From n4tua at aol.com Mon Jan 2 22:26:17 2017 From: n4tua at aol.com (Collin) Date: Mon, 2 Jan 2017 22:26:17 -0500 Subject: [AMRadio] GK500 OTA almost Message-ID: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> Dear AMers, I am having a time with this Globe King 500B. I have it ready to make RF but no modulation yet. Something is just not right and I can't quite put my finger on it yet. Maybe some of you have had an experience like this and might be able to lend me a hand. Tuning the final goes fairly well until I take it out of tune and the full screen voltage is applied to the final. Tuning is very touchy acting and reaches a point where plate current suddenly pegs the meter and some arcing/flashing happens inside of the tube. I can tame this and get it to stay stabilized but increasing loading and the plate current pegs. Any ideas? I have cleaned and secured grounding of tune and load air variable capacitors and also disassembled each air variable and cleaned and buffed all contact surfaces. I have cleaned the final tank band switch. I have inspected every connection and contact between the antenna connector and the plate cap on the final amp. I will not give up! Good Day, Collin From w5jo at brightok.net Mon Jan 2 22:50:48 2017 From: w5jo at brightok.net (w5jo at brightok.net) Date: Mon, 2 Jan 2017 21:50:48 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> Message-ID: <09EDBFB3452D48BF9DE4BC35BA818FEE@JimPC> Is the set unmodified in the tank circuit? If it is stock, check the mica capacitors on the coarse loading switch or the contacts on the switch (I have seen the switch mis-wired). Have the coils been changed in any way? You don't mention which band, is it on 160, 80, 40 or all of them? That is just a shot in the dark. Jim W5JO -----Original Message----- Dear AMers, I am having a time with this Globe King 500B. I have it ready to make RF but no modulation yet. Something is just not right and I can't quite put my finger on it yet. Maybe some of you have had an experience like this and might be able to lend me a hand. Tuning the final goes fairly well until I take it out of tune and the full screen voltage is applied to the final. Tuning is very touchy acting and reaches a point where plate current suddenly pegs the meter and some arcing/flashing happens inside of the tube. I can tame this and get it to stay stabilized but increasing loading and the plate current pegs. Any ideas? I have cleaned and secured grounding of tune and load air variable capacitors and also disassembled each air variable and cleaned and buffed all contact surfaces. I have cleaned the final tank band switch. I have inspected every connection and contact between the antenna connector and the plate cap on the final amp. I will not give up! Good Day, Collin From ranchorobbo at gmail.com Tue Jan 3 05:57:02 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Tue, 3 Jan 2017 04:57:02 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> Message-ID: Don't give up--I almost did a few times with a rig here but when it finally got on the air it was like when I was 5 years old at Christmas. I've never owned a Globe King but it sounds like the final PA breaks into parasitic oscillation. Get a cheap crummy battery powered transistor FM broadcast receiver, something with a telescoping whip and 9 v. or 2 AA batteries and put it between stations and next to or on top if the rig. Don't know the parasitic frequency for the tube but my experience has been if the final oscillates you hear a lot of hash on the cheap FM set. The parasitic choke can be fine but if there is a grounding problem, rusty rivets, poor bonding between chassis and panel, tube socket and chassis, and most important, the bonding between the output pi net caps and ground (chassis) that can set things off. If the output pi net caps are connected to the chassis via the front panel that could be your problem. Keep in mind the problem could be something else entirely--I'm just an armchair troubleshooter. 73 Rob K5UJ On 1/2/17, Collin via AMRadio wrote: > > Dear AMers, > I am having a time with this Globe King 500B. I have it ready to make RF but > no modulation yet. > Something is just not right and I can't quite put my finger on it yet. Maybe > some of you have had an experience like this and might be able to lend me a > hand. > Tuning the final goes fairly well until I take it out of tune and the full > screen voltage is applied to the final. Tuning is very touchy acting and > reaches a point where plate current suddenly pegs the meter and some > arcing/flashing happens inside of the tube. I can tame this and get it to > stay stabilized but increasing loading and the plate current pegs. Any > ideas? > I have cleaned and secured grounding of tune and load air variable > capacitors and also disassembled each air variable and cleaned and buffed > all contact surfaces. I have cleaned the final tank band switch. I have > inspected every connection and contact between the antenna connector and the > plate cap on the final amp. > I will not give up! > From jcandela at prodigy.net Tue Jan 3 07:22:39 2017 From: jcandela at prodigy.net (Jim Candela) Date: Tue, 3 Jan 2017 12:22:39 +0000 (UTC) Subject: [AMRadio] GK500 OTA almost In-Reply-To: References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> Message-ID: <1753326871.5846020.1483446159315@mail.yahoo.com> It's been? while since I have owned a GK 500B. The RF PA stage is not neutralized, and therefore it tends to be slightly unstable from some regeneration. On the upper bands, plate dip and screen current max does not coincide with maximum output. That said, it is not prone to parasitics either. With many class C RF amplifiers, opening up the loading capacitor in the Pi net allows a greater amount of harmonic energy to reach the RF output, and also might push the final RF amp closer to instability. I would try to go simplistic and use a crystal instead of the VFO. This eliminates one form of RF ingress. Many GK owners use a copper braid chassis to chassis, one piece, straight up and down. If the RF PA tube has been flashing inside, the tube might be toast...but not necessarily the cause of the problem A neon bulb fastened to a popsicle stick, and placed near the PA tube plate will glow orange when transmitting. Whenever there is a parasitic, the bulb color will shift to violet. Don't hold that stick...just place it nearby, hot melt it in place. Is the instability there when transmitting into a good 50 ohm dummy load? Also see the post from K1JJ here:"on air tuning causing stability issues" http://amfone.net/Amforum/index.php?topic=42379.0 JimWd5JKO On Tuesday, January 3, 2017 4:57 AM, Rob Atkinson wrote: Don't give up--I almost did a few times with a rig here but when it finally got on the air it was like when I was 5 years old at Christmas. I've never owned a Globe King but it sounds like the final PA breaks into parasitic oscillation.? Get a cheap crummy battery powered transistor FM broadcast receiver, something with a telescoping whip and 9 v. or 2 AA batteries and put it between stations and next to or on top if the rig.? Don't know the parasitic frequency for the tube but my experience has been if the final oscillates you hear a lot of hash on the cheap FM set. The parasitic choke can be fine but if there is a grounding problem, rusty rivets, poor bonding between chassis and panel, tube socket and chassis, and most important, the bonding between the output pi? net caps and ground (chassis) that can set things off. If the output pi net caps are connected to the chassis via the front panel that could be your problem.? Keep in mind the problem could be something else entirely--I'm just an armchair troubleshooter. 73 Rob K5UJ On 1/2/17, Collin via AMRadio wrote: > > Dear AMers, > I am having a time with this Globe King 500B. I have it ready to make RF but > no modulation yet. > Something is just not right and I can't quite put my finger on it yet. Maybe > some of you have had an experience like this and might be able to lend me a > hand. > Tuning the final goes fairly well until I take it out of tune and the full > screen voltage is applied to the final. Tuning is very touchy acting and > reaches a point where plate current suddenly pegs the meter and some > arcing/flashing happens inside of the tube. I can tame this and get it to > stay stabilized but increasing loading and the plate current pegs. Any > ideas? > I have cleaned and secured grounding of tune and load air variable > capacitors and also disassembled each air variable and cleaned and buffed > all contact surfaces. I have cleaned the final tank band switch. I have > inspected every connection and contact between the antenna connector and the > plate cap on the final amp. > I will not give up! > ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Archives: http://mailman.qth.net/pipermail/amradio/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio at mailman.qth.net To unsubscribe, send an email to amradio-request at mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jcandela at prodigy.net From n4tua at aol.com Tue Jan 3 08:33:35 2017 From: n4tua at aol.com (Collin) Date: Tue, 3 Jan 2017 08:33:35 -0500 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <1753326871.5846020.1483446159315@mail.yahoo.com> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> <1753326871.5846020.1483446159315@mail.yahoo.com> Message-ID: <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> Well, I have had many great responses. Thank you all. First of all some more info. I am testing using a cantenna dummy load with only the RF deck and the Power Supply deck lashed together with a home-brew HV power supply made from parts of an old BC-610 PS. Rectifiers are SS and all of the rest of the PS is BC-610 parts. I am using a variac to dial down the HV to about 1800 vdc. I am monitoring HV as I go. I am using a crystal and it is on 3883 kcs. The final tank is stock. There is some problem with the coarse load switch but the problem contact finger is not being used. Parasitic oscillations sound possible. Now that I think about it there is NO parasitic choke. I will have to look at the schematic when I get back home to see if it is shown. It did not have one when I got it. My 2 meter rig nearby does occasionally pick up hash when key down on GK500. I hope everyone who replied to my post can see all of the responses here. I will send my comments to the reflector so all can see. Thank you, Collin > On Jan 3, 2017, at 7:22 AM, Jim Candela wrote: > > > It's been while since I have owned a GK 500B. The RF PA stage is not neutralized, and therefore it tends to be slightly unstable from some regeneration. On the upper bands, plate dip and screen current max does not coincide with maximum output. That said, it is not prone to parasitics either. With many class C RF amplifiers, opening up the loading capacitor in the Pi net allows a greater amount of harmonic energy to reach the RF output, and also might push the final RF amp closer to instability. > > I would try to go simplistic and use a crystal instead of the VFO. This eliminates one form of RF ingress. > > Many GK owners use a copper braid chassis to chassis, one piece, straight up and down. > > If the RF PA tube has been flashing inside, the tube might be toast...but not necessarily the cause of the problem > > A neon bulb fastened to a popsicle stick, and placed near the PA tube plate will glow orange when transmitting. Whenever there is a parasitic, the bulb color will shift to violet. Don't hold that stick...just place it nearby, hot melt it in place. > > Is the instability there when transmitting into a good 50 ohm dummy load? > > Also see the post from K1JJ here: > "on air tuning causing stability issues" > http://amfone.net/Amforum/index.php?topic=42379.0 > > Jim > Wd5JKO > > > > > > On Tuesday, January 3, 2017 4:57 AM, Rob Atkinson wrote: > > > Don't give up--I almost did a few times with a rig here but when it > finally got on the air it was like when I was 5 years old at > Christmas. > > I've never owned a Globe King but it sounds like the final PA breaks > into parasitic oscillation. Get a cheap crummy battery powered > transistor FM broadcast receiver, something with a telescoping whip > and 9 v. or 2 AA batteries and put it between stations and next to or > on top if the rig. Don't know the parasitic frequency for the tube > but my experience has been if the final oscillates you hear a lot of > hash on the cheap FM set. > > The parasitic choke can be fine but if there is a grounding problem, > rusty rivets, poor bonding between chassis and panel, tube socket and > chassis, and most important, the bonding between the output pi net > caps and ground (chassis) that can set things off. > > If the output pi net caps are connected to the chassis via the front > panel that could be your problem. Keep in mind the problem could be > something else entirely--I'm just an armchair troubleshooter. > > 73 > > Rob > K5UJ > > > On 1/2/17, Collin via AMRadio wrote: > > > > Dear AMers, > > I am having a time with this Globe King 500B. I have it ready to make RF but > > no modulation yet. > > Something is just not right and I can't quite put my finger on it yet. Maybe > > some of you have had an experience like this and might be able to lend me a > > hand. > > Tuning the final goes fairly well until I take it out of tune and the full > > screen voltage is applied to the final. Tuning is very touchy acting and > > reaches a point where plate current suddenly pegs the meter and some > > arcing/flashing happens inside of the tube. I can tame this and get it to > > stay stabilized but increasing loading and the plate current pegs. Any > > ideas? > > I have cleaned and secured grounding of tune and load air variable > > capacitors and also disassembled each air variable and cleaned and buffed > > all contact surfaces. I have cleaned the final tank band switch. I have > > inspected every connection and contact between the antenna connector and the > > plate cap on the final amp. > > I will not give up! > > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Archives: http://mailman.qth.net/pipermail/amradio/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio at mailman.qth.net > To unsubscribe, send an email to amradio-request at mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to jcandela at prodigy.net > > From ars.w5omr at gmail.com Tue Jan 3 08:46:12 2017 From: ars.w5omr at gmail.com (Geoff) Date: Tue, 3 Jan 2017 07:46:12 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> <1753326871.5846020.1483446159315@mail.yahoo.com> <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> Message-ID: On 01/03/2017 07:33 AM, Collin via AMRadio wrote: > Well, I have had many great responses. Thank you all. > First of all some more info. I am testing using a cantenna dummy load with only the RF deck and the Power Supply deck lashed together with a home-brew HV power supply made from parts of an old BC-610 PS. Rectifiers are SS and all of the rest of the PS is BC-610 parts. I am using a variac to dial down the HV to about 1800 vdc. I am monitoring HV as I go. > I am using a crystal and it is on 3883 kcs. > The final tank is stock. There is some problem with the coarse load switch but the problem contact finger is not being used. > Parasitic oscillations sound possible. Now that I think about it there is NO parasitic choke. I will have to look at the schematic when I get back home to see if it is shown. It did not have one when I got it. My 2 meter rig nearby does occasionally pick up hash when key down on GK500. > I hope everyone who replied to my post can see all of the responses here. I will send my comments to the reflector so all can see. > > > Thank you, Collin A great resource on the Globe King 500 would be Mike/WA5CMI in Garland, TX. Not sure Mike is a member of this group, but he's taking a GK500 and stripped it down to the bare chassis, and rebuilt the thing all the way back to being on the air. He's on 3.890 with that GK500 *at this time* and usually on every morning on 3.890, Monday thru Saturday, from about 6:30am till they get done. 73 = Best Regards, -Geoff/W5OMR From ranchorobbo at gmail.com Tue Jan 3 09:08:29 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Tue, 3 Jan 2017 08:08:29 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> <1753326871.5846020.1483446159315@mail.yahoo.com> <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> Message-ID: > Now that I think about it there is NO parasitic choke. I will have to look at the schematic when I get back home to see if it is shown. It did not have one when I got it. My 2 meter rig nearby does occasionally pick up hash when key down on GK500. > Oh my gosh, first thing is to get a couple 2 watt 200 ohm carbons and parallel them and strip some no. 14 solid copper wire and wind a 4 turn coil around the resistors and put that assembly in series with the plate and see what that does. coil diameter 1/2 inch 1/16 inch spacing between turns approximately. rob k5uj From w5jo at brightok.net Tue Jan 3 10:01:42 2017 From: w5jo at brightok.net (w5jo at brightok.net) Date: Tue, 3 Jan 2017 09:01:42 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com><1753326871.5846020.1483446159315@mail.yahoo.com> <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> Message-ID: <3ABDDAA793EA4BFD8096102ACCBC0588@JimPC> When things are right with the RF deck a parasitic suppressor is not needed on the plate of the final tube. The design by WRL did not use one. There is one on the plate of the driver, a 6146. What is the condition of that one? Is there any evidence of burn marks or arcing of the RF choke feeding the plate of the tube. Is there a doorknob bypass at the bottom of the choke and one beside the input for the HV? If so, what is their condition? Do you know the condition of the tube itself? Have you a spare 4-400 or even a 4-250 you can try? What about the RF bypass capacitors, .005? Any burn marks or cracked discs around the socket of the final? The one I have tunes smoothly from 160 meters all the way up through 10 meters. Because of the size of the variable, it is delicate but it works. Did you start trying to tune with the coarse switch in the #6 position and reduce it after the plate dips? I tune into a cantenna before putting mine on the air and, when tuned that switch is in the #2 position. Jim W5JO -----Original Message----- Well, I have had many great responses. Thank you all. First of all some more info. I am testing using a cantenna dummy load with only the RF deck and the Power Supply deck lashed together with a home-brew HV power supply made from parts of an old BC-610 PS. Rectifiers are SS and all of the rest of the PS is BC-610 parts. I am using a variac to dial down the HV to about 1800 vdc. I am monitoring HV as I go. I am using a crystal and it is on 3883 kcs. The final tank is stock. There is some problem with the coarse load switch but the problem contact finger is not being used. Parasitic oscillations sound possible. Now that I think about it there is NO parasitic choke. I will have to look at the schematic when I get back home to see if it is shown. It did not have one when I got it. My 2 meter rig nearby does occasionally pick up hash when key down on GK500. I hope everyone who replied to my post can see all of the responses here. I will send my comments to the reflector so all can see. Thank you, Collin From zehelmer at yahoo.com Tue Jan 3 11:34:20 2017 From: zehelmer at yahoo.com (zehelmer at yahoo.com) Date: Tue, 3 Jan 2017 16:34:20 +0000 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <3ABDDAA793EA4BFD8096102ACCBC0588@JimPC> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com><1753326871.5846020.1483446159315@mail.yahoo.com> <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> <3ABDDAA793EA4BFD8096102ACCBC0588@JimPC> Message-ID: <9585.78621.bm@smtp213.mail.bf1.yahoo.com> Hello! I had to Google for updated OTA: Over-the-air programming (OTA) refers to various methods of distributing new software, configuration settings, and even updating encryption keys to devices like cellphones, set-top boxes or secure voice communication equipment (encrypted 2-way radios). One important feature of OTA is that one central location can send an update to all the users, who are unable to refuse, defeat, or alter that update, and that the update applies immediately to everyone on the channel. A user could "refuse" OTA but the "channel manager" could also "kick them off" the channel automatically. - Are we going to keep our OTA? ? *** Happy New Year *** Jose? Silva / CT1AXG Enviado do Correio para Windows 10 De: w5jo at brightok.net Enviado: 3 de janeiro de 2017 15:03 Para: Collin; AM Radio Reflector Assunto: Re: [AMRadio] GK500 OTA almost When things are right with the RF deck a parasitic suppressor is not needed on the plate of the final tube. The design by WRL did not use one. There is one on the plate of the driver, a 6146. What is the condition of that one? Is there any evidence of burn marks or arcing of the RF choke feeding the plate of the tube. Is there a doorknob bypass at the bottom of the choke and one beside the input for the HV? If so, what is their condition? Do you know the condition of the tube itself? Have you a spare 4-400 or even a 4-250 you can try? What about the RF bypass capacitors, .005? Any burn marks or cracked discs around the socket of the final? The one I have tunes smoothly from 160 meters all the way up through 10 meters. Because of the size of the variable, it is delicate but it works. Did you start trying to tune with the coarse switch in the #6 position and reduce it after the plate dips? I tune into a cantenna before putting mine on the air and, when tuned that switch is in the #2 position. Jim W5JO -----Original Message----- Well, I have had many great responses. Thank you all. First of all some more info. I am testing using a cantenna dummy load with only the RF deck and the Power Supply deck lashed together with a home-brew HV power supply made from parts of an old BC-610 PS. Rectifiers are SS and all of the rest of the PS is BC-610 parts. I am using a variac to dial down the HV to about 1800 vdc. I am monitoring HV as I go. I am using a crystal and it is on 3883 kcs. The final tank is stock. There is some problem with the coarse load switch but the problem contact finger is not being used. Parasitic oscillations sound possible. Now that I think about it there is NO parasitic choke. I will have to look at the schematic when I get back home to see if it is shown. It did not have one when I got it. My 2 meter rig nearby does occasionally pick up hash when key down on GK500. I hope everyone who replied to my post can see all of the responses here. I will send my comments to the reflector so all can see. Thank you, Collin ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Archives: http://mailman.qth.net/pipermail/amradio/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio at mailman.qth.net To unsubscribe, send an email to amradio-request at mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to zehelmer at yahoo.com From jcandela at prodigy.net Tue Jan 3 12:23:30 2017 From: jcandela at prodigy.net (Jim Candela) Date: Tue, 3 Jan 2017 17:23:30 +0000 (UTC) Subject: [AMRadio] GK500 OTA almost In-Reply-To: <9585.78621.bm@smtp213.mail.bf1.yahoo.com> References: <73450FAE-C4CC-48DD-981B-5B3571C12904@aol.com> <1753326871.5846020.1483446159315@mail.yahoo.com> <2750ED83-B37B-4403-8D14-31D3306A9414@aol.com> <3ABDDAA793EA4BFD8096102ACCBC0588@JimPC> <9585.78621.bm@smtp213.mail.bf1.yahoo.com> Message-ID: <1628213289.6021016.1483464210188@mail.yahoo.com> Good point! "Over-the-air programming (OTA) refers to various methods of distributing new software, configuration settings, and even updating encryption keys to devices like cellphones, set-top boxes or secure voice communication equipment (encrypted 2-way radios)" The GK500A does not have a VFO, so if they run Rev B firmware in a Rev A GK, then they will either get a checksum error or a 404 error. Then of course if one goes to www.wrl.com in Council Bluffs Iowa, they can download the correct firmware. If there are any questions, email Leo at Leo.Myerson at wrl.com JimWd5JKO On Tuesday, January 3, 2017 10:34 AM, CT1AXG via AMRadio wrote: Hello! I had to Google for updated OTA: Over-the-air programming (OTA) refers to various methods of distributing new software, configuration settings, and even updating encryption keys to devices like cellphones, set-top boxes or secure voice communication equipment (encrypted 2-way radios). One important feature of OTA is that one central location can send an update to all the users, who are unable to refuse, defeat, or alter that update, and that the update applies immediately to everyone on the channel. A user could "refuse" OTA but the "channel manager" could also "kick them off" the channel automatically. - Are we going to keep our OTA? ? *** Happy New Year *** Jose? Silva / CT1AXG Enviado do Correio para Windows 10 De: w5jo at brightok.net Enviado: 3 de janeiro de 2017 15:03 Para: Collin; AM Radio Reflector Assunto: Re: [AMRadio] GK500 OTA almost When things are right with the RF deck a parasitic suppressor is not needed on the plate of the final tube.? The design by WRL did not use one. There is one on the plate of the driver, a 6146.? What is the condition of that one? Is there any evidence of burn marks or arcing of the RF choke feeding the plate of the tube.? Is there a doorknob bypass at the bottom of the choke and one beside the input for the HV?? If so, what is their condition? Do you know the condition of the tube itself?? Have you a spare 4-400 or even a 4-250 you can try? What about the RF bypass capacitors, .005?? Any burn marks or cracked discs around the socket of the final? The one I have tunes smoothly from 160 meters all the way up through 10 meters.? Because of the size of the variable, it is delicate but it works. Did you start trying to tune with the coarse switch in the #6 position and reduce it after the plate dips?? I tune into a cantenna before putting mine on the air and, when tuned that switch is in the #2 position. Jim W5JO -----Original Message----- Well, I have had many great responses. Thank you all. First of all some more info. I am testing using a cantenna dummy load with only the RF deck and the Power Supply deck lashed together with a? home-brew HV power supply made from parts of an old BC-610 PS. Rectifiers are SS and all of the rest of the PS is BC-610 parts. I am using a variac to dial down the HV to about 1800 vdc. I am monitoring HV as I go. I am using a crystal and it is on 3883 kcs. The final tank is stock. There is some problem with the coarse load switch but the problem contact finger is not being used. Parasitic oscillations sound possible.? Now that I think about it there is NO parasitic choke. I will have to look at the schematic when I get back home to see if it is shown. It did not have one when I got it. My 2 meter rig nearby does occasionally pick up hash when key down on GK500. I hope everyone who replied to my post can see all of the responses here. I will send my comments to the reflector so all can see. Thank you, Collin ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Archives: http://mailman.qth.net/pipermail/amradio/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio at mailman.qth.net To unsubscribe, send an email to amradio-request at mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to zehelmer at yahoo.com ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Archives: http://mailman.qth.net/pipermail/amradio/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio at mailman.qth.net To unsubscribe, send an email to amradio-request at mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jcandela at prodigy.net From kb2wig at twcny.rr.com Tue Jan 3 15:17:50 2017 From: kb2wig at twcny.rr.com (kb2wig at twcny.rr.com) Date: Tue, 3 Jan 2017 20:17:50 +0000 Subject: [AMRadio] Merry Christmass, Festivus, Hanukkah and a happy New Year Message-ID: <20170103201750.XKMGK.236662.root@cdptpa-web10> The header says it all.... .. I hope I didn't leave anyone out. Best Wishes to the List, KLC From jcandela at prodigy.net Tue Jan 3 16:46:44 2017 From: jcandela at prodigy.net (Jim Candela) Date: Tue, 3 Jan 2017 21:46:44 +0000 (UTC) Subject: [AMRadio] GK500 OTA almost In-Reply-To: <26D0A7C5-8D3E-4CD9-990B-221316148199@aol.com> References: <26D0A7C5-8D3E-4CD9-990B-221316148199@aol.com> Message-ID: <540747595.6274322.1483480004245@mail.yahoo.com> Collin, ??? One thing I remember on my GK-500B was the single screen bypass capacitor for the 4-400 tube. It was something like a 0.002 uf Mica-mold condenser. I replaced mine with four 500PF HV caps, two on each G2 pin, and then going to each grounding to a socket hold down screw using a solder type terminal lug. I also bypassed the filament leads in a similar way, but the exact details escape me now. I do recall that those changes made the King load up closer to ideal....max out and MIN plate current dip, and when the screen current was at a peak...In fact I liked to use the loading control to get no more than ~ 40ma screen current. ?? The GK 500 has a high impedance Screen supply, therefore the screen voltage rises as the screen current drops. It might be something like 600V at 20ma screen, and 400v at 100ma screen. The screen current on a tetrode drops as the tube is heavily loaded, and therefore the screen voltage rises. Perhaps your in a situation where loading to > 300ma plate current causes the screen voltage to go too high, and then the power sensitivity will be so high that a parasitic is more likely?? The screen bypassing, and a whole host of issues might be at play here, but the point however is that low screen current from a heavily loaded plate current might make parasitic oscillation more possible. It just depends how much regeneration you got going on..You don't want to solid state that screen supply. JimWd5JKO On Tuesday, January 3, 2017 2:39 PM, Collin wrote: I will check out the buffer amp parasitic choke when I get home. The RF plate choke looks good and I see no burn or scorched areas. I will pull the HV bypass capacitors and check them.? Good Day, Collin "You can live to be a hundred if you give up all the things that make you want to live to be a hundred."??Woody Allen On Jan 3, 2017, at 12:23 PM, Jim Candela wrote: Jim W5JO From n4tua at aol.com Tue Jan 3 21:21:26 2017 From: n4tua at aol.com (Collin) Date: Tue, 3 Jan 2017 21:21:26 -0500 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <540747595.6274322.1483480004245@mail.yahoo.com> References: <26D0A7C5-8D3E-4CD9-990B-221316148199@aol.com> <540747595.6274322.1483480004245@mail.yahoo.com> Message-ID: <72ADDDA5-BFF0-40B6-B206-2AF0A28B033D@aol.com> Now wait a minute. I may be sleepy but I think that there is a wiring problem in the buffer amp plate circuit. It is not wired like the schematic. Anyway, I am out of time right now. Will be back in front of it tomorrow evening. More to come. You guys are giving me all sorts of things to look at and I am so slow. I may be on to something in this buffer amp plate circuit though. I took the parasitic choke out and there was a capacitor attached with it, they both checked good but while looking at the schematic verses what was hooked up something looks wrong. Let me tell you about this jewel. I bought it for a song but it was in sad shape when I got it. It had been sitting in a barn and then in a carport and had been wet and did I say rusty? Really rusty. I tore it down and sandblasted the chassis and painted them. Then cleaned and checked this as I reassembled. Painted transformers back to black. It looks nice. I have not done the front panels yet. I want RF out if this rig first. Anyway, you might be able to tell, at this point that I am in a personal relationship with this mess. Have been for years. Told you I was slow. So for now goodnight, see you at 0415. Good Day, Collin "You can live to be a hundred if you give up all the things that make you want to live to be a hundred." Woody Allen > On Jan 3, 2017, at 4:46 PM, Jim Candela wrote: > > Collin, > > One thing I remember on my GK-500B was the single screen bypass capacitor for the 4-400 tube. It was something like a 0.002 uf Mica-mold condenser. I replaced mine with four 500PF HV caps, two on each G2 pin, and then going to each grounding to a socket hold down screw using a solder type terminal lug. I also bypassed the filament leads in a similar way, but the exact details escape me now. I do recall that those changes made the King load up closer to ideal....max out and MIN plate current dip, and when the screen current was at a peak...In fact I liked to use the loading control to get no more than ~ 40ma screen current. > > The GK 500 has a high impedance Screen supply, therefore the screen voltage rises as the screen current drops. It might be something like 600V at 20ma screen, and 400v at 100ma screen. The screen current on a tetrode drops as the tube is heavily loaded, and therefore the screen voltage rises. Perhaps your in a situation where loading to > 300ma plate current causes the screen voltage to go too high, and then the power sensitivity will be so high that a parasitic is more likely?? The screen bypassing, and a whole host of issues might be at play here, but the point however is that low screen current from a heavily loaded plate current might make parasitic oscillation more possible. It just depends how much regeneration you got going on..You don't want to solid state that screen supply. > > Jim > Wd5JKO > > > On Tuesday, January 3, 2017 2:39 PM, Collin wrote: > > > I will check out the buffer amp parasitic choke when I get home. The RF plate choke looks good and I see no burn or scorched areas. I will pull the HV bypass capacitors and check them. > Good Day, Collin > > "You can live to be a hundred if you give up all the things that make you want to live to be a hundred." Woody Allen > > > >> On Jan 3, 2017, at 12:23 PM, Jim Candela wrote: >> >> Jim >> W5JO > > From Tonne at Comcast.net Wed Jan 4 16:26:23 2017 From: Tonne at Comcast.net (Jim Tonne) Date: Wed, 4 Jan 2017 16:26:23 -0500 Subject: [AMRadio] Article about allpass networks Message-ID: <586D687F.8010007@Comcast.net> I have just written a paper about allpass networks and how they can benefit the AM guy. Comments are invited. See it here: http://tonnesoftware.com/appnotes/allpass/Allpass.pdf - Jim Tonne W4ENE From ranchorobbo at gmail.com Wed Jan 4 20:10:00 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Wed, 4 Jan 2017 19:10:00 -0600 Subject: [AMRadio] Article about allpass networks In-Reply-To: <586D687F.8010007@Comcast.net> References: <586D687F.8010007@Comcast.net> Message-ID: Is this the same thing as an all-pass filter? tnx Rob K5UJ From ranchorobbo at gmail.com Wed Jan 4 20:12:19 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Wed, 4 Jan 2017 19:12:19 -0600 Subject: [AMRadio] What happened when the power went off Message-ID: What happened to AM radio (and Millennials) http://www.huffingtonpost.com/fred-lundgren/what-happened-to-am-radio_b_13876742.html Rob K5UJ From Tonne at Comcast.net Wed Jan 4 20:33:21 2017 From: Tonne at Comcast.net (Jim Tonne) Date: Wed, 4 Jan 2017 20:33:21 -0500 Subject: [AMRadio] Article about allpass networks In-Reply-To: References: <586D687F.8010007@Comcast.net> Message-ID: <586DA261.3030101@Comcast.net> Yes it is. - JimT On 1/4/2017 8:10 PM, Rob Atkinson wrote: > Is this the same thing as an all-pass filter? > > tnx > > Rob > K5UJ > From mjcal77 at yahoo.com Wed Jan 4 20:52:39 2017 From: mjcal77 at yahoo.com (CL in NC) Date: Thu, 5 Jan 2017 01:52:39 +0000 (UTC) Subject: [AMRadio] Power off is fun References: <709914701.154705.1483581159774.ref@mail.yahoo.com> Message-ID: <709914701.154705.1483581159774@mail.yahoo.com> Interesting article, millennials lack of understanding of how everyday things work, or don't work is quite common which also follows into millennials as hams too, in many cases. That may explain the love of the SDR and it's computer interface. I agree though, when the power goes off around here, my battery supplied VLF rig comes out and it is amazing how quiet the band is, even at midday. Strange the FCC is all worried about hams on the VLF interfering with whatever, but all that whatever is allowed to obliterate everything else on or near its spectrum. Charlie W4MEC in NC From n4tua at aol.com Wed Jan 4 21:45:23 2017 From: n4tua at aol.com (Collin) Date: Wed, 4 Jan 2017 21:45:23 -0500 Subject: [AMRadio] GK500 OTA almost Message-ID: <46E6BE32-1A98-4424-9F69-B7A3E61F355C@aol.com> OK, Jim, I think I am posting with reply all. Here goes. I had a few minutes to work on the GK500B tonight and checked the schematic again around the buffer amp plate circuit. One capacitor is not connected as it is shown on the schematic. Incidentally, the same capacitor on the crystal oscillator is misconnected the same way. Although, I don't think it makes any difference because that capacitor blocks DC from going through the coil in either position. I have the luxury of having a junker to compare with also and it is wire the same way as my keeper, different from what the schematic shows. That is not the only problem I have found with this GK500B documentation. There are two resistors with different values that what the parts list shows. Both of these check out on my junker example also. So, I did find what might be a poor ground on the bypass capacitor at the DC input to the plate choke. I have cleaned it up and reassembled everything. Check these, buffer amp parasitic choke and blocking capacitor final amp DC input bypass capacitors (2) and plate choke All look and test good. Tomorrow evening I will fire it up again and note any changes in results. I hate to do to many things and fix the problem and then not know what it actually was that caused the problem. Best 73rds, Collin > On Jan 3, 2017, at 9:21 PM, Collin wrote: > > Now wait a minute. I may be sleepy but I think that there is a wiring problem in the buffer amp plate circuit. It is not wired like the schematic. > > Anyway, I am out of time right now. Will be back in front of it tomorrow evening. More to come. You guys are giving me all sorts of things to look at and I am so slow. I may be on to something in this buffer amp plate circuit though. I took the parasitic choke out and there was a capacitor attached with it, they both checked good but while looking at the schematic verses what was hooked up something looks wrong. > > Let me tell you about this jewel. I bought it for a song but it was in sad shape when I got it. It had been sitting in a barn and then in a carport and had been wet and did I say rusty? Really rusty. I tore it down and sandblasted the chassis and painted them. Then cleaned and checked this as I reassembled. Painted transformers back to black. It looks nice. I have not done the front panels yet. I want RF out if this rig first. Anyway, you might be able to tell, at this point that I am in a personal relationship with this mess. Have been for years. Told you I was slow. > > So for now goodnight, see you at 0415. > > > Good Day, Collin > > "You can live to be a hundred if you give up all the things that make you want to live to be a hundred." Woody Allen > > > >> On Jan 3, 2017, at 4:46 PM, Jim Candela wrote: >> >> Collin, >> >> One thing I remember on my GK-500B was the single screen bypass capacitor for the 4-400 tube. It was something like a 0.002 uf Mica-mold condenser. I replaced mine with four 500PF HV caps, two on each G2 pin, and then going to each grounding to a socket hold down screw using a solder type terminal lug. I also bypassed the filament leads in a similar way, but the exact details escape me now. I do recall that those changes made the King load up closer to ideal....max out and MIN plate current dip, and when the screen current was at a peak...In fact I liked to use the loading control to get no more than ~ 40ma screen current. >> >> The GK 500 has a high impedance Screen supply, therefore the screen voltage rises as the screen current drops. It might be something like 600V at 20ma screen, and 400v at 100ma screen. The screen current on a tetrode drops as the tube is heavily loaded, and therefore the screen voltage rises. Perhaps your in a situation where loading to > 300ma plate current causes the screen voltage to go too high, and then the power sensitivity will be so high that a parasitic is more likely?? The screen bypassing, and a whole host of issues might be at play here, but the point however is that low screen current from a heavily loaded plate current might make parasitic oscillation more possible. It just depends how much regeneration you got going on..You don't want to solid state that screen supply. >> >> Jim >> Wd5JKO >> >> >> On Tuesday, January 3, 2017 2:39 PM, Collin wrote: >> >> >> I will check out the buffer amp parasitic choke when I get home. The RF plate choke looks good and I see no burn or scorched areas. I will pull the HV bypass capacitors and check them. >> Good Day, Collin >> >> "You can live to be a hundred if you give up all the things that make you want to live to be a hundred." Woody Allen >> >> >> >>> On Jan 3, 2017, at 12:23 PM, Jim Candela wrote: >>> >>> Jim >>> W5JO >> >> > From ranchorobbo at gmail.com Wed Jan 4 21:52:54 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Wed, 4 Jan 2017 20:52:54 -0600 Subject: [AMRadio] Power off is fun In-Reply-To: <709914701.154705.1483581159774@mail.yahoo.com> References: <709914701.154705.1483581159774.ref@mail.yahoo.com> <709914701.154705.1483581159774@mail.yahoo.com> Message-ID: I think FCC was worried about hams QRMing Power Line Communications instead of the other way around, which was or is ridiculous given the ham LF or VLF power limit. Millennials looking at a GE Superadio--What is that? Incredible. 73 Rob K5UJ On 1/4/17, CL in NC via AMRadio wrote: > Interesting article, millennials lack of understanding of how everyday > things work, or don't work is quite common which also follows into > millennials as hams too, in many cases. That may explain the love of the > SDR and it's computer interface. I agree though, when the power goes off > around here, my battery supplied VLF rig comes out and it is amazing how > quiet the band is, even at midday. Strange the FCC is all worried about > hams on the VLF interfering with whatever, but all that whatever is allowed > to obliterate everything else on or near its spectrum. From w5jo at brightok.net Wed Jan 4 22:41:17 2017 From: w5jo at brightok.net (w5jo at brightok.net) Date: Wed, 4 Jan 2017 21:41:17 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <46E6BE32-1A98-4424-9F69-B7A3E61F355C@aol.com> References: <46E6BE32-1A98-4424-9F69-B7A3E61F355C@aol.com> Message-ID: You are and thanks for posting so everyone can see. WRL documentation is sometimes terrible Collin. Also there is always the possibility that the set has been "modified" by previous owners which can make thing more difficult. I think I speak for everyone here, we are here to help if you want. Jim W5JO Moderator -----Original Message----- OK, Jim, I think I am posting with reply all. Here goes. I had a few minutes to work on the GK500B tonight and checked the schematic again around the buffer amp plate circuit. One capacitor is not connected as it is shown on the schematic. Incidentally, the same capacitor on the crystal oscillator is misconnected the same way. Although, I don't think it makes any difference because that capacitor blocks DC from going through the coil in either position. I have the luxury of having a junker to compare with also and it is wire the same way as my keeper, different from what the schematic shows. That is not the only problem I have found with this GK500B documentation. There are two resistors with different values that what the parts list shows. Both of these check out on my junker example also. So, I did find what might be a poor ground on the bypass capacitor at the DC input to the plate choke. I have cleaned it up and reassembled everything. Check these, buffer amp parasitic choke and blocking capacitor final amp DC input bypass capacitors (2) and plate choke All look and test good. Tomorrow evening I will fire it up again and note any changes in results. I hate to do to many things and fix the problem and then not know what it actually was that caused the problem. Best 73rds, Collin From ranchorobbo at gmail.com Thu Jan 5 06:31:29 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Thu, 5 Jan 2017 05:31:29 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: References: <46E6BE32-1A98-4424-9F69-B7A3E61F355C@aol.com> Message-ID: > > WRL documentation is sometimes terrible Collin. One of the first things I had to discover is that manufacturer schematics are often not telling me what I should see for the item in front of me. A lot of them made little changes in mid-production without changing the schematics or parts lists. If you run out of 200 ohm resistors and have to keep the assembly line going you raid the 400 ohms and parallel two and keep moving but a manual re-print for that? Too costly. In the old days computer inventorying and next day shipping didn't exist. Rob K5UJ From n4tua at aol.com Thu Jan 5 08:39:57 2017 From: n4tua at aol.com (Collin) Date: Thu, 5 Jan 2017 08:39:57 -0500 Subject: [AMRadio] GK500 OTA almost Message-ID: <0A17E8A5-466C-4887-9DF1-1E9725CFD6B6@aol.com> Jim, I know WRL used what was available and what was cheap. The example though I noticed was in the final amp screen grid circuit there is a resistor which the parts list shows 2500 ohm, 20 watt. The actual part used is 25K ohm, 20 watt. The part in my keeper and both junkers are all the same and look original. When I found this, I really thought I had something. Now, I just don't know and left it alone like it was. Good Day, Collin On Jan 5, 2017, at 6:31 AM, Rob Atkinson wrote: >> >> WRL documentation is sometimes terrible Collin. > > One of the first things I had to discover is that manufacturer > schematics are often not telling me what I should see for the item in > front of me. > > A lot of them made little changes in mid-production without changing > the schematics or parts lists. If you run out of 200 ohm resistors > and have to keep the assembly line going you raid the 400 ohms and > parallel two and keep moving but a manual re-print for that? Too > costly. > > In the old days computer inventorying and next day shipping didn't exist. > > Rob > K5UJ > From w5jo at brightok.net Thu Jan 5 09:17:13 2017 From: w5jo at brightok.net (w5jo at brightok.net) Date: Thu, 5 Jan 2017 08:17:13 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <0A17E8A5-466C-4887-9DF1-1E9725CFD6B6@aol.com> References: <0A17E8A5-466C-4887-9DF1-1E9725CFD6B6@aol.com> Message-ID: <07209DD7A2B443DFB507147A17D92D70@JimPC> I am not surprised, they did not spend a lot of time proof reading it seems. The copy of the manual I have shows that screen dropping resistor to be 20K and your units have 25K. Another example is my 500A has a parasitic suppressor in the driver plate lead but the manual that came with the unit does not show it. The manual is the original document furnished by the WRL in 1954. Jim W5JO -----Original Message----- Jim, I know WRL used what was available and what was cheap. The example though I noticed was in the final amp screen grid circuit there is a resistor which the parts list shows 2500 ohm, 20 watt. The actual part used is 25K ohm, 20 watt. The part in my keeper and both junkers are all the same and look original. When I found this, I really thought I had something. Now, I just don't know and left it alone like it was. Good Day, Collin From k4kyv at charter.net Thu Jan 5 15:32:34 2017 From: k4kyv at charter.net (Donald Chester) Date: Thu, 5 Jan 2017 14:32:34 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: References: <46E6BE32-1A98-4424-9F69-B7A3E61F355C@aol.com> Message-ID: <000701d26792$d8ef8e30$8aceaa90$@charter.net> > A lot of them made little changes in mid-production without changing > the schematics or parts lists. If you run out of 200 ohm resistors > and have to keep the assembly line going you raid the 400 ohms and parallel > two and keep moving but a manual re-print for that? Too costly. One of the worst offenders for this was the UTC transformer company. They sometimes made drastic changes in the essential characteristics of some of their transformers without making any change in the type number, not even adding an "-A" suffix. One example is a power transformer that had plate, rectifier filament, bias, and tube filament windings. The filament winding on the original was 2.5 volts. Later editions of that same transformer, with no alteration of the type number, were identical to the original except that the filament winding was changed to 6.3 volts. An unwary customer might have purchased a newer version of the transformer to replace a burnt-out original, and unknowingly zap all the 2.5 volt tubes with 6.3 volts, until the 6.3 volt winding gave up the ghost because all the 2.5 volt tubes wired in parallel put a near dead-short load on it. Another example was a broadcast-grade class B driver transformer, in which they drastically altered the step-down turns ratio without changing the transformer's type number. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus From k4kyv at charter.net Thu Jan 5 18:15:34 2017 From: k4kyv at charter.net (Donald Chester) Date: Thu, 5 Jan 2017 17:15:34 -0600 Subject: [AMRadio] How Radio Works Message-ID: <000101d267a9$9e685fa0$db391ee0$@charter.net> 1943 video but love the old buzzardly equipment that could be from a decade earlier. Extremely simplified, elementary presentation, but technically correct. The guy speaks with that peculiar movie/radio accent you hear in 1930s recordings; I don't think people ever actually talked like that. https://www.youtube.com/watch?v=jqGAneO79lY --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus From n4tua at aol.com Thu Jan 5 21:30:11 2017 From: n4tua at aol.com (Collin) Date: Thu, 5 Jan 2017 21:30:11 -0500 Subject: [AMRadio] GK500 OTA almost Message-ID: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> Great Day, we got it. I believe the GK500B is behaving now. It was parasitic oscillations and Rob hit it right on. I should have tried that first. Took two 240 ohm two watt carbon resistors from the junk box. Didn't have any 200 ohm. Paralleled them and wound 4 turns of wire around and replaced that copper strap with my new lash up. Now she tunes very smooth and predictable with NO arc/flash and no wild uncontrollable plate current. There may well be other GK500s out there that would benefit from this simple and cheap modification. You guys on here are great and I thank each of you for the inspiration and help. This is a great community of AMers. Your right Rob, I feel like a 5 year old at Christmas. Now, to get that modulator deck put back together. Stay tuned. Good Day, Collin On Jan 5, 2017, at 6:31 AM, Rob Atkinson wrote: >> >> WRL documentation is sometimes terrible Collin. > > One of the first things I had to discover is that manufacturer > schematics are often not telling me what I should see for the item in > front of me. > > A lot of them made little changes in mid-production without changing > the schematics or parts lists. If you run out of 200 ohm resistors > and have to keep the assembly line going you raid the 400 ohms and > parallel two and keep moving but a manual re-print for that? Too > costly. > > In the old days computer inventorying and next day shipping didn't exist. > > Rob > K5UJ > From w8au at sssnet.com Thu Jan 5 22:05:12 2017 From: w8au at sssnet.com (w8au at sssnet.com) Date: Thu, 05 Jan 2017 22:05:12 -0500 Subject: [AMRadio] How Radio Works In-Reply-To: <000101d267a9$9e685fa0$db391ee0$@charter.net> References: <000101d267a9$9e685fa0$db391ee0$@charter.net> Message-ID: At 06:15 PM 1/5/2017, Donald Chester wrote: >1943 video but love the old buzzardly equipment that could be from a >decade earlier. Extremely simplified, elementary presentation, but >technically correct. The guy speaks with that peculiar movie/radio accent >you hear in 1930s recordings; I don't think people ever actually talked like >that. Don: Years ago a local Classical FM station did Saturday night fun nights. One of the skits was "How Radio Announcers converse with each other when meeting on the street." You get the idea... :-D Great stuff! Perry w8au >https://www.youtube.com/watch?v=jqGAneO79lY From don.kd2fo at gmail.com Thu Jan 5 22:21:56 2017 From: don.kd2fo at gmail.com (Don Rasmussen) Date: Thu, 5 Jan 2017 22:21:56 -0500 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> References: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> Message-ID: I believe you may need to NEUTRALIZE the final. Any grid driven Class C final will need to be neutralized. Sometimes you can avoid re-neutralizing going to new final , but maybe not. To neutralize you need to REMOVE BOTH PLATE & SCREEN VOLTAGE.....then listen with a sensitive device coupled to the GK-500 plate circuit, while applying normal grid drive.....up o the 10 or 15 meter band. There is a neutralizing capacitor which should be tuned for MINIMUM RF "FEED-THROUGH"? on your sensitive device (i.e. rcvr s-meter reading) coupled to the temporarily disable RF plate circuit. When the procedure is finished , re-connect both PLATE and SCREEN vooltages to the tube for normal operation. CAUTION.....IF PLATE VOLTAGE IS REMOVED WITHOUT DISCONNECTING SCREEN VOLTAGE.....YOU WILL BURN UP THE SCREEN INSTANTLY. I am the owner of a GK-500A (currently running a 4-400A) and you have my opinion.....even if there is some other issue, for best NON-OSCILLATING operation of the final.....it SHOULD BE NEUTRALIZED. A badly out of neutralization final will OSCILLATE.....it sounds like this is possibly your problem. 73, Don KD2FO From don.kd2fo at gmail.com Thu Jan 5 22:34:03 2017 From: don.kd2fo at gmail.com (Don Rasmussen) Date: Thu, 5 Jan 2017 22:34:03 -0500 Subject: [AMRadio] GK500 OTA almost In-Reply-To: References: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> Message-ID: Further Note.....I just wrote suggesting neutralizing the final of the GK-500. IF there is NOT a neutralizing capacitor installed on your rig, please see the ARRL Handbook (older issues) to see where to place a neutralizing capacitor on grid driven amplifier projects.....this could well save the day for an amplifier that is "a little unstable" ! 73, Don KD2FO P.S. - Vacuum tube Heathkit AM Transmitters Just used a Wire sticking up through the chassis (insulated from chassis - of course) up fully along side the final tube, which could be bent back and forth for proper coupling to the tube plate....inside the envelope. This forms a nice neutralizing capacitor for many TETRODE FINALS.....which require less neutralizing capacity than triode finals ! On Thu, Jan 5, 2017 at 10:21 PM, Don Rasmussen wrote: > I believe you may need to NEUTRALIZE the final. Any grid driven Class > C final will need to be neutralized. Sometimes you can avoid > re-neutralizing going to new final , but maybe not. > > To neutralize you need to REMOVE BOTH PLATE & SCREEN VOLTAGE.....then > listen with a sensitive device coupled to the GK-500 plate circuit, while > applying normal grid drive.....up o the 10 or 15 meter band. There is > a neutralizing capacitor which should be tuned for MINIMUM RF > "FEED-THROUGH"? on your sensitive device (i.e. rcvr s-meter reading) > coupled to the temporarily disable RF plate circuit. > > When the procedure is finished , re-connect both PLATE and SCREEN > vooltages to the tube for normal operation. > > CAUTION.....IF PLATE VOLTAGE IS REMOVED WITHOUT DISCONNECTING SCREEN > VOLTAGE.....YOU WILL BURN UP THE SCREEN INSTANTLY. > > I am the owner of a GK-500A (currently running a 4-400A) and you have my > opinion.....even if there is some other issue, for best NON-OSCILLATING > operation of the final.....it SHOULD BE NEUTRALIZED. A badly out of > neutralization final will OSCILLATE.....it sounds like this is possibly > your problem. > > 73, Don KD2FO > From ranchorobbo at gmail.com Fri Jan 6 05:53:38 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Fri, 6 Jan 2017 04:53:38 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> References: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> Message-ID: Glad you got it working Colin & hope to hear you on the air with it. Hope the audio is smooth sailing also. 73 Rob K5UJ On 1/5/17, Collin wrote: > Great Day, we got it. I believe the GK500B is behaving now. It was parasitic > oscillations and Rob hit it right on. I should have tried that first. Took > two 240 ohm two watt carbon resistors from the junk box. Didn't have any 200 > ohm. Paralleled them and wound 4 turns of wire around and replaced that > copper strap with my new lash up. Now she tunes very smooth and predictable > with NO arc/flash and no wild uncontrollable plate current. There may well > be other GK500s out there that would benefit from this simple and cheap > modification. From jcandela at prodigy.net Fri Jan 6 07:06:34 2017 From: jcandela at prodigy.net (Jim Candela) Date: Fri, 6 Jan 2017 12:06:34 +0000 (UTC) Subject: [AMRadio] GK500 OTA almost In-Reply-To: References: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> Message-ID: <1630157379.1119038.1483704394446@mail.yahoo.com> Collin, ? ?I am glad you made progress. Is it really fixed though? Think of this like a regenerative receiver that was breaking into oscillation. What you did could have been similar to turning the regen knob CCW till it wasn't oscillating. But is there enough regeneration left that might make the GK 500 final unstable under various tuning conditions and then under modulation? ? ?What I and others said still might need to be considered. Look at plate dip, screen peak, and maximum RF output. If they do not ALL occur at the same point, then the PA stage might take off under certain conditions, kind of like a dog seeing the tip of his tail, and deciding to go for it, round and round. ? ?Others have mentioned neutralization. This would be ideal, but WRL and Leo made a trade off to NOT do that. Doing so now might be a bigger project than what you want to take on. ? ?The neon bulb trick is handy here. Anytime it goes from orange to violet you have VHF/UHF energy present.? JimWd5JKO On Friday, January 6, 2017 4:53 AM, Rob Atkinson wrote: Glad you got it working Colin & hope to hear you on the air with it. Hope the audio is smooth sailing also. 73 Rob K5UJ On 1/5/17, Collin wrote: > Great Day, we got it. I believe the GK500B is behaving now. It was parasitic > oscillations and Rob hit it right on. I should have tried that first. Took > two 240 ohm two watt carbon resistors from the junk box. Didn't have any 200 > ohm. Paralleled them and wound 4 turns of wire around and replaced that > copper strap with my new lash up. Now she tunes very smooth and predictable > with NO arc/flash and no wild uncontrollable plate current. There may well > be other GK500s out there that would benefit from this simple and cheap > modification. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Archives: http://mailman.qth.net/pipermail/amradio/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio at mailman.qth.net To unsubscribe, send an email to amradio-request at mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jcandela at prodigy.net From ranchorobbo at gmail.com Fri Jan 6 12:46:19 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Fri, 6 Jan 2017 11:46:19 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: <1630157379.1119038.1483704394446@mail.yahoo.com> References: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> <1630157379.1119038.1483704394446@mail.yahoo.com> Message-ID: On Fri, Jan 6, 2017 at 6:06 AM, Jim Candela wrote: > Collin, > > I am glad you made progress. Is it really fixed though? \ agree with some of Jim's comments but if it looks like a duck, quacks like a duck, walks like a duck, it's a duck. IOW, the rig's problems are reportedly gone. In my book that means it got fixed. Don't get too anal looking for probs that don't exist, however, it's a good idea to check for neutralization by dipping the plate and seeing if the grid current peaks at the same time. A common misunderstanding regarding plate parasitic suppressors is that they stop oscillation. Actually they create an environment where they are simply not possible at all. > Think of this > like a regenerative receiver that was breaking into oscillation. What you > did could have been similar to turning the regen knob CCW till it wasn't > oscillating. But is there enough regeneration left that might make the GK > 500 final unstable under various tuning conditions and then under > modulation? > > What I and others said still might need to be considered. Look at plate > dip, screen peak, and maximum RF output. If they do not ALL occur at the > same point, then the PA stage might take off under certain conditions, kind > of like a dog seeing the tip of his tail, and deciding to go for it, round > and round. > > Others have mentioned neutralization. This would be ideal, but WRL and > Leo made a trade off to NOT do that. Doing so now might be a bigger project > than what you want to take on. that occurred to me also. You might be into modifying the grid input to get the capacitor back to the grid out of phase. But I don't know anything about the GK tetrode rig so I'm out of my area. 73 Rob K5UJ From n4tua at aol.com Fri Jan 6 13:31:58 2017 From: n4tua at aol.com (Collin) Date: Fri, 6 Jan 2017 13:31:58 -0500 Subject: [AMRadio] GK500 OTA almost In-Reply-To: References: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> <1630157379.1119038.1483704394446@mail.yahoo.com> Message-ID: <7C9CCC9C-1EC2-4756-9121-83E6D6F03312@aol.com> I am reluctant to reinvent the wheel so to speak. It is working and making much RF. I will investigate a little better as I go with the scope and the watt meter. I am not sure how to add neutralization to this rig. The plate current moves up and down smoothly and equally as I rock the tune capacitor back and forth from resonance and the screen current peaks at resonance and and dips on either side. Much unlike it was doing. Good Day, Collin > On Jan 6, 2017, at 12:46 PM, Rob Atkinson wrote: > >> On Fri, Jan 6, 2017 at 6:06 AM, Jim Candela wrote: >> Collin, >> >> I am glad you made progress. Is it really fixed though? \ > > > agree with some of Jim's comments but if it looks like a duck, quacks > like a duck, walks like a duck, it's a duck. IOW, the rig's problems > are reportedly gone. In my book that means it got fixed. > Don't get too anal looking for probs that don't exist, however, it's a > good idea to check for neutralization by dipping the plate and seeing > if the grid current peaks at the same time. > > A common misunderstanding regarding plate parasitic suppressors is > that they stop oscillation. Actually they create an environment where > they are simply not possible at all. > > >> Think of this >> like a regenerative receiver that was breaking into oscillation. What you >> did could have been similar to turning the regen knob CCW till it wasn't >> oscillating. But is there enough regeneration left that might make the GK >> 500 final unstable under various tuning conditions and then under >> modulation? >> >> What I and others said still might need to be considered. Look at plate >> dip, screen peak, and maximum RF output. If they do not ALL occur at the >> same point, then the PA stage might take off under certain conditions, kind >> of like a dog seeing the tip of his tail, and deciding to go for it, round >> and round. >> >> Others have mentioned neutralization. This would be ideal, but WRL and >> Leo made a trade off to NOT do that. Doing so now might be a bigger project >> than what you want to take on. > > that occurred to me also. You might be into modifying the grid input > to get the capacitor back to the grid out of phase. But I don't know > anything about the GK tetrode rig so I'm out of my area. > > 73 > > Rob > K5UJ From k4kyv at charter.net Fri Jan 6 14:41:24 2017 From: k4kyv at charter.net (Donald Chester) Date: Fri, 6 Jan 2017 13:41:24 -0600 Subject: [AMRadio] GK500 OTA almost In-Reply-To: References: <581B73FE-19E0-43ED-8336-9B45A01F51F6@aol.com> Message-ID: <001301d26854$dd1729b0$97457d10$@charter.net> > I believe you may need to NEUTRALIZE the final. Any grid driven Class C > final will need to be neutralized. Sometimes you can avoid > re-neutralizing going to new final , but maybe not. Some grid-driven tetrode and pentode finals can eek by without neutralisation if carefully laid out. Given the "value engineering" that went into the GK-500, it doesn't surprise me that this may have been needed but wasn't included in the stock design, just like the parasitic suppressors. > > To neutralize you need to REMOVE BOTH PLATE & SCREEN VOLTAGE..... Something else, seldom mentioned in the handbooks but which I found from experience, is that with a single-ended neutralised TRIODE final, the +HV lead from the plate supply must be PHYSICALLY DISCONNECTED from the PA. Just switching off the power supply isn't enough. If there is DC continuity from the tube's plate to ground through the power supply components, as soon as grid drive is applied, you may see a phantom plate current indication even though there is no +HV on the final. With MV rectifiers, this phantom current may be enough to cause a visible blue glow in the tubes. When grid drive is applied to the final, some of the electrons attracted to the grid from the cathode when the grid swings positive at RF cycle peaks, will miss the grid and continue on to the plate even though it has no positive DC plate voltage. With DC continuity, these electrons will seek ground, causing a pulsating DC plate current to flow in step with the RF peaks. This pulsating DC appears as an RF voltage in the tank circuit, and can make accurate neutralisation impossible, since the tank will still show the presence of RF feed-through even when the neutralising capacitor is set properly. Physically disconnecting the +HV lead will make this problem go away, since the electrons no longer have a path to ground. I have not noticed this in the case of a push-pull triode final; evidently the phantom plate currents in each of the two tubes balance each other out. I see the phantom plate current in the 211 driver stage of my HF-300 rig, but none in push-pull final, and it neutralises OK without the lead disconnected, although I usually do so anyway just to make sure. I have had limited experience with screen-grid tubes, so I can't say whether or not this is ever a problem with tetrodes and pentodes. Don k4kyv --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus From tobiebw2 at newmexico.com Sat Jan 7 17:01:57 2017 From: tobiebw2 at newmexico.com (Steve Wender) Date: Sat, 7 Jan 2017 15:01:57 -0700 Subject: [AMRadio] Electro-impulse PM-19 dummy load Message-ID: Hi all, I am tinkering with an Electro-impulse mode PM-19 dummy load which has a power meter and range scale. It does not work on the higher ranges. Does anyone know anything about this unit? I am now going to try to trace out the circuit. Thanks, Steve KC5WN From mjcal77 at yahoo.com Sat Jan 7 18:18:27 2017 From: mjcal77 at yahoo.com (CL in NC) Date: Sat, 7 Jan 2017 23:18:27 +0000 (UTC) Subject: [AMRadio] Burn in, yes or no? References: <1711957213.559873.1483831107144.ref@mail.yahoo.com> Message-ID: <1711957213.559873.1483831107144@mail.yahoo.com> I hope this question does not take off on a tangent, but needed some input on firing up an old amp. A fellow ham gave me a Heath SB200 he wants me to check out and sell for him. The amp had not been turned on in at least 10 years. I did the usual, ohm check and bring it up on the variac, etc., tubes out of course, and it seems to be working OK just sitting there making HV. Only needed to replace one 4.7 M resistor in the HV meter string to get the meter to read right. Would you put the tubes in, go back on the variac and with HV disconnected, bring up the 572B filaments a little at a time over several hours? These are Cetron tubes, and the amp and tubes do show some mileage. Charlie, W4MEC in NC From ranchorobbo at gmail.com Sat Jan 7 19:41:30 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Sat, 7 Jan 2017 18:41:30 -0600 Subject: [AMRadio] Burn in, yes or no? In-Reply-To: <1711957213.559873.1483831107144@mail.yahoo.com> References: <1711957213.559873.1483831107144.ref@mail.yahoo.com> <1711957213.559873.1483831107144@mail.yahoo.com> Message-ID: Hi Charlie, I'd run the filaments only for a few hours and then use the variac to put the h.v. at 1 KV and put the amp in transmit and let the idle current run for 10 minutes or so. If no problems I'd put in on full B+ and try it with drive. I don't know how those tubes are gettered--I don't know if the anode has to show color or not. I have cetrons in my 75 m. rig modulator and they're good 572Bs. 73 Rob K5UJ From n4tua at aol.com Mon Jan 9 06:36:52 2017 From: n4tua at aol.com (Collin) Date: Mon, 9 Jan 2017 06:36:52 -0500 Subject: [AMRadio] AMRadio Digest, Vol 156, Issue 6 In-Reply-To: References: Message-ID: <68B05FE9-E558-4A4B-939F-1303E7752EFB@aol.com> I did not get much time to be with the GK this past weekend but I did make some progress. Fired it up again with a 7050 kc crystal and tuned up nicely on 40 and 20 meters. Listening on a monitor receiver sounds great. Good sounding tone with no ripple, keying circuit works. Will know more about key shape when I get the scope inline. Need to lash up some more coax jumpers and get the watt meter hooked up to. Good Day, Collin > On Jan 6, 2017, at 1:32 PM, amradio-request at mailman.qth.net wrote: > > Send AMRadio mailing list submissions to > amradio at mailman.qth.net > > To subscribe or unsubscribe via the World Wide Web, visit > http://mailman.qth.net/mailman/listinfo/amradio > or, via email, send a message with subject or body 'help' to > amradio-request at mailman.qth.net > > You can reach the person managing the list at > amradio-owner at mailman.qth.net > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of AMRadio digest..." > Today's Topics: > > 1. Re: GK500 OTA almost (Don Rasmussen) > 2. Re: GK500 OTA almost (Rob Atkinson) > 3. Re: GK500 OTA almost (Jim Candela) > 4. Re: GK500 OTA almost (Rob Atkinson) > 5. Re: GK500 OTA almost (Collin) > > > > > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio at mailman.qth.net From n4tua at aol.com Mon Jan 9 22:00:09 2017 From: n4tua at aol.com (Collin) Date: Mon, 9 Jan 2017 22:00:09 -0500 Subject: [AMRadio] AMRadio Digest, Vol 156, Issue 6 In-Reply-To: References: Message-ID: I did get the watt meter inline with the Globe King 500B this evening and tuned up on the crystals I have been using to test out the RF deck and homespun power supply. I was able to squeeze out 310 watts on 3883 kc 350 watts on 7050 kc Ran out of time on 14100 kc Looking good so far. I'm going to break it down and work on the modulator deck next. I stripped all of the decks down to the chassis and blasted them because they were badly rusted when I got it. Rebuilding each component by component as I reassemble them. Let me tell you about my HV power supply. Or should I say more accurately MV power supply. The HV transformer on this GK was replaced before I got it with a huge potted transformer that did not even fit on the chassis. What a mess, it was hanging over the edges and too big physically but that was not all, it was shorted and I could not repair it. Found a sad looking junker BC-610 power supply deck with a leaky oil filled transformer and all of the parts needed to make a 3000 volt plus power supply. Gutted the leaky oil filled transformer and salvaged the core, it is fine and works great air cooled. Long story short this GK will have a forth deck, an external power supply for the final amplifier tube. Good Day, Collin > On Jan 6, 2017, at 1:32 PM, amradio-request at mailman.qth.net wrote: > > Send AMRadio mailing list submissions to > amradio at mailman.qth.net > > To subscribe or unsubscribe via the World Wide Web, visit > http://mailman.qth.net/mailman/listinfo/amradio > or, via email, send a message with subject or body 'help' to > amradio-request at mailman.qth.net > > You can reach the person managing the list at > amradio-owner at mailman.qth.net > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of AMRadio digest..." > Today's Topics: > > 1. Re: GK500 OTA almost (Don Rasmussen) > 2. Re: GK500 OTA almost (Rob Atkinson) > 3. Re: GK500 OTA almost (Jim Candela) > 4. Re: GK500 OTA almost (Rob Atkinson) > 5. Re: GK500 OTA almost (Collin) > > > > > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio at mailman.qth.net From mjcal77 at yahoo.com Mon Jan 9 22:12:58 2017 From: mjcal77 at yahoo.com (CL in NC) Date: Tue, 10 Jan 2017 03:12:58 +0000 (UTC) Subject: [AMRadio] 'A' battery References: <1277240296.86297.1484017978178.ref@mail.yahoo.com> Message-ID: <1277240296.86297.1484017978178@mail.yahoo.com> I have an older radio with 1.5V filament, and after researching since I have no info on what type battery fit in it, the battery box takes a cell that has the dimensions of a 'G' cell. The G today is a modern lithium for some gadget, but has anybody ever seen a G cell anywhere? Other than a physical description on a few sites, no pictures exist. If it is not a G and the G is about the height of 2 C cells stacked, has anybody seen a battery box that takes 2 C cells, puts them in line and + to -, with no connection between them such that you have a double C cell battery but only 1.5 volts out? A lantern battery contains 4 F cells, and even though half again bigger than a D, still too short. Tried a few vintage radio sites for their knowledge, but no luck. I have tried building a 1.5 v power supply to drive this, but the filter requirements are extremely hard to meet. Even the slightest ripple in the single digit millivolt range makes the radio buzz, where battery power is dead quiet. Charlie, W4MEC in NC From ka1kaq at gmail.com Tue Jan 10 00:13:13 2017 From: ka1kaq at gmail.com (Todd, KA1KAQ) Date: Tue, 10 Jan 2017 00:13:13 -0500 Subject: [AMRadio] 'A' battery In-Reply-To: <1277240296.86297.1484017978178@mail.yahoo.com> References: <1277240296.86297.1484017978178.ref@mail.yahoo.com> <1277240296.86297.1484017978178@mail.yahoo.com> Message-ID: Sounds like one of those funky 50s batteries, Charlie. Something weird like a long C cell with a 9 volt type clip on one end? I have a number of sets here that use 1.5 volt filament voltage, but their A cell is/was a typical old dry cell. Haven't seen one of those in years, but at least someone is making cases that you can stuff a bunch of D cells into and it looks the same. Been playing with an old Radiola Senior lately with a single WD-11 tube. A lot of fun. I use a single D cell for filament and three 9 volt cells for the B voltage. Bought a few cheapy plastic battery holders online and hooked them to a board. Not pretty but works fine. ~ Todd, KA1KAQ/4 On Mon, Jan 9, 2017 at 10:12 PM, CL in NC via AMRadio < amradio at mailman.qth.net> wrote: > I have an older radio with 1.5V filament, and after researching since I > have no info on what type battery fit in it, the battery box takes a cell > that has the dimensions of a 'G' cell. The G today is a modern lithium for > some gadget, but has anybody ever seen a G cell anywhere? Other than a > physical description on a few sites, no pictures exist. If it is not a G > and the G is about the height of 2 C cells stacked, has anybody seen a > battery box that takes 2 C cells, puts them in line and + to -, with no > connection between them such that you have a double C cell battery but only > 1.5 volts out? A lantern battery contains 4 F cells, and even though half > again bigger than a D, still too short. Tried a few vintage radio sites > for their knowledge, but no luck. I have tried building a 1.5 v power > supply to drive this, but the filter requirements are extremely hard to > meet. Even the slightest ripple in the single digit millivolt range makes > the radio buzz, where battery power > is dead quiet. > > Charlie, W4MEC in NC > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Archives: http://mailman.qth.net/pipermail/amradio/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio at mailman.qth.net > To unsubscribe, send an email to amradio-request at mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to ka1kaq at gmail.com > From ars.w5omr at gmail.com Tue Jan 10 13:14:55 2017 From: ars.w5omr at gmail.com (Geoff) Date: Tue, 10 Jan 2017 12:14:55 -0600 Subject: [AMRadio] 'A' battery In-Reply-To: References: <1277240296.86297.1484017978178.ref@mail.yahoo.com> <1277240296.86297.1484017978178@mail.yahoo.com> Message-ID: <4c0775bd-f1b1-b6b6-3b43-f8e90c62c19f@gmail.com> On 01/09/2017 11:13 PM, Todd, KA1KAQ wrote: > Sounds like one of those funky 50s batteries, Charlie. Something weird like > a long C cell with a 9 volt type clip on one end? Back in High School, in the Radio and TV class I was taking, I came across a 9v looking battery - had the same exact 9v looking clip on top, but it was about 2.5 times 'longer' than a 9v. I had developed the habit of touching the 9v batteries to my tongue to see how/if they were charged. I tried that with this thing I found - just like the 9v's... a very quick, ever so slight touch on the tongue and ... the Lights went Out! I found myself knocked over a row of desks and flat on my butt! Got my nerves back together again, and found that offensive temporary storage of 'Hell Fury waiting to be unleashed' and looked at the thing, and while it had the Cat jumping through the O in Ray-O-Vac, underneath that, in very clear, plain and distinctive lettering, were the numerals 45 and the letter V afterward. In all my 17 years of being raised with a Ham Operator/Broadcast Chief Engineer, I'd never -seen- a 45v battery before, let alone -heard- of one.... Oh, and I don't 'taste' batteries anymore after that, either. Theventy three = Betht Regardth -Geoff/W5OMR From Ron.K3PID at sbcglobal.net Tue Jan 24 19:39:47 2017 From: Ron.K3PID at sbcglobal.net (K3PID) Date: Tue, 24 Jan 2017 18:39:47 -0600 Subject: [AMRadio] HMR 2017 Message-ID: In case you didn?t get the latest issue of ER, Ray has scheduled the 2017 Heavy Metal Rally for Saturday Feb. 4th... Hope to see ( er hear ) many members of this group... 73 Ron K3PID, T368 & R390 ( non A) From don.kd2fo at gmail.com Wed Jan 25 07:25:00 2017 From: don.kd2fo at gmail.com (Don Rasmussen) Date: Wed, 25 Jan 2017 07:25:00 -0500 Subject: [AMRadio] HMR 2017 In-Reply-To: References: Message-ID: I'd like the frequency & Time for "The Heavy Metal Rally" in February 4th. 73, Don kd2fo On Tue, Jan 24, 2017 at 7:39 PM, K3PID wrote: > In case you didn?t get the latest issue of ER, Ray has scheduled the 2017 > Heavy Metal Rally for Saturday Feb. 4th... Hope to see ( er hear ) many > members of this group... > > 73 > Ron K3PID, T368 & R390 ( non A) > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Archives: http://mailman.qth.net/pipermail/amradio/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio at mailman.qth.net > To unsubscribe, send an email to amradio-request at mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to don.kd2fo at gmail.com From ranchorobbo at gmail.com Wed Jan 25 09:47:40 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Wed, 25 Jan 2017 08:47:40 -0600 Subject: [AMRadio] HMR 2017 In-Reply-To: References: Message-ID: In ER, Ray didn't specify a frequency beyond the so-called "AM Window" on 75 m., 3870 to 3890 if you ask me. He also advised tuning around and listening for stations. Rob K5UJ On Wed, Jan 25, 2017 at 6:25 AM, Don Rasmussen wrote: > I'd like the frequency & Time for "The Heavy Metal Rally" in February 4th. > > 73, Don kd2fo > > From don.kd2fo at gmail.com Wed Jan 25 10:19:19 2017 From: don.kd2fo at gmail.com (Don Rasmussen) Date: Wed, 25 Jan 2017 10:19:19 -0500 Subject: [AMRadio] HMR 2017 In-Reply-To: References: Message-ID: Thank you Rob.....see you there ! Hoping to put my Globe King 500 back on the air by then. 73, Don kd2fo On Wed, Jan 25, 2017 at 9:47 AM, Rob Atkinson wrote: > In ER, Ray didn't specify a frequency beyond the so-called "AM Window" > on 75 m., 3870 to 3890 if you ask me. He also advised tuning around > and listening for stations. > > Rob > K5UJ > > On Wed, Jan 25, 2017 at 6:25 AM, Don Rasmussen > wrote: > > I'd like the frequency & Time for "The Heavy Metal Rally" in February > 4th. > > > > 73, Don kd2fo > > > > > From k4kyv at charter.net Wed Jan 25 13:11:23 2017 From: k4kyv at charter.net (Donald Chester) Date: Wed, 25 Jan 2017 12:11:23 -0600 Subject: [AMRadio] HMR 2017 In-Reply-To: References: Message-ID: <001c01d27736$6fc9ef50$4f5dcdf0$@charter.net> > In ER, Ray didn't specify a frequency beyond the so-called "AM Window" > on 75 m., 3870 to 3890 if you ask me. He also advised tuning around and > listening for stations. > > Rob > K5UJ I'd say operate on any frequency your licence allows. Don k4kyv --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

This page last updated 17 Oct 2017.