From w5jo at brightok.net Sat Nov 1 11:32:31 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Sat, 1 Nov 2014 10:32:31 -0500 Subject: [AMRadio] Tektronix repair Message-ID: <24660CB1E95B47D1BAA29A43A36AFC7C@JimPC> Is there anyone who repairs Tek scopes other than professional labs? I have a couple that need repairs but am just too shaky to do it. It would be nice if they are close to me to lessen the shipping costs. I am in Oklahoma. Jim W5JO From kj4hyd at gmail.com Sat Nov 1 12:32:48 2014 From: kj4hyd at gmail.com (Kevin Raper) Date: Sat, 1 Nov 2014 12:32:48 -0400 Subject: [AMRadio] Tektronix repair In-Reply-To: <24660CB1E95B47D1BAA29A43A36AFC7C@JimPC> References: <24660CB1E95B47D1BAA29A43A36AFC7C@JimPC> Message-ID: On Nov 1, 2014, at 11:32 AM, Jim Wilhite wrote: > Is there anyone who repairs Tek scopes other than professional labs? I have a couple that need repairs but am just too shaky to do it. It would be nice if they are close to me to lessen the shipping costs. I am in Oklahoma. Try this guy, He is known to do better than OEM work. http://michaelpatton.com 73, Kevin Raper KJ4HYD CE WCKI WQIZ WLTQ There is no limitation to the fidelity of AM radio. From a mathematical standpoint, AM does better in frequency response than FM. - Leonard Kahn From amradio at mailman.qth.net Mon Nov 3 18:35:34 2014 From: amradio at mailman.qth.net (Don Merz via AMRadio) Date: Mon, 3 Nov 2014 23:35:34 +0000 (UTC) Subject: [AMRadio] Tektronix repair In-Reply-To: <24660CB1E95B47D1BAA29A43A36AFC7C@JimPC> References: <24660CB1E95B47D1BAA29A43A36AFC7C@JimPC> Message-ID: <2057536538.434559.1415057734973.JavaMail.yahoo@jws10662.mail.bf1.yahoo.com> Unless you are a collector who wants a working vintage scope, the chances of this being economical are slim and none. You can almost certainly go buy a good working scope for less than the repair cost of the ones you have. It's a 2014 harsh reality.? 73 de N3RHT From: Jim Wilhite To: AM Radio List Sent: Saturday, November 1, 2014 11:32 AM Subject: [AMRadio] Tektronix repair Is there anyone who repairs Tek scopes other than professional labs?? I have a couple that need repairs but am just too shaky to do it.? It would be nice if they are close to me to lessen the shipping costs.? I am in Oklahoma. Jim W5JO ______________________________________________________________ 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 From w3slk at verizon.net Mon Nov 3 19:13:54 2014 From: w3slk at verizon.net (w3slk at verizon.net) Date: Mon, 03 Nov 2014 19:13:54 -0500 Subject: [AMRadio] Tektronix repair In-Reply-To: <2057536538.434559.1415057734973.JavaMail.yahoo@jws10662.mail.bf1.yahoo.com> References: <24660CB1E95B47D1BAA29A43A36AFC7C@JimPC> <2057536538.434559.1415057734973.JavaMail.yahoo@jws10662.mail.bf1.yahoo.com> Message-ID: <5D4FAABEEF324B28AB9A1FC20CE4D6EC@MikeyPC> Not to play pile on, but I have done repairs on many of Tektronix equipment. If you have the service manual, then you are in shape to fix it yourself. At least in my opinion, Tek manuals were the best in the business. I used to repair their old copiers, printers, plotters, scopes, digital terminals etc. If I were you, I would take a shot at it myself. Mod-U-Lator, Mike(y) W3SLK -----Original Message----- From: Don Merz via AMRadio Sent: Monday, November 3, 2014 6:35 PM To: Jim Wilhite ; AM Radio List Subject: Re: [AMRadio] Tektronix repair Unless you are a collector who wants a working vintage scope, the chances of this being economical are slim and none. You can almost certainly go buy a good working scope for less than the repair cost of the ones you have. It's a 2014 harsh reality. 73 de N3RHT From: Jim Wilhite To: AM Radio List Sent: Saturday, November 1, 2014 11:32 AM Subject: [AMRadio] Tektronix repair Is there anyone who repairs Tek scopes other than professional labs? I have a couple that need repairs but am just too shaky to do it. It would be nice if they are close to me to lessen the shipping costs. I am in Oklahoma. Jim W5JO ______________________________________________________________ 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 ______________________________________________________________ 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 From w5jo at brightok.net Mon Nov 3 22:06:35 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Mon, 3 Nov 2014 21:06:35 -0600 Subject: [AMRadio] Tektronix repair In-Reply-To: <5D4FAABEEF324B28AB9A1FC20CE4D6EC@MikeyPC> References: <24660CB1E95B47D1BAA29A43A36AFC7C@JimPC> <2057536538.434559.1415057734973.JavaMail.yahoo@jws10662.mail.bf1.yahoo.com> <5D4FAABEEF324B28AB9A1FC20CE4D6EC@MikeyPC> Message-ID: <703E562998224E15B7F3B79C254439CE@JimPC> Thanks for the suggestions guys. But (a big word), the scope I have in mind is a 485 and I am sort of attached to it and have the cart for it. I believe it is a 350 Mc scope and works fine other than the traces do not respond to the position control properly. I really can't tell you why I want it fixed but just thought if I could find someone, I would do it. As for repairing things now a days, it is difficult Mike. I have trouble keeping from burning wires in my Champion or King. Not only that my eyes are not what they were even a year ago. Believe me it is hell getting old but it is sort of fun, but not in cases like this. I do have the manuals for it but have trouble with reading it. Tnx and 73 guys Jim W5JO -----Original Message----- Not to play pile on, but I have done repairs on many of Tektronix equipment. If you have the service manual, then you are in shape to fix it yourself. At least in my opinion, Tek manuals were the best in the business. I used to repair their old copiers, printers, plotters, scopes, digital terminals etc. If I were you, I would take a shot at it myself. Mod-U-Lator, Mike(y) W3SLK -----Original Message----- Unless you are a collector who wants a working vintage scope, the chances of this being economical are slim and none. You can almost certainly go buy a good working scope for less than the repair cost of the ones you have. It's a 2014 harsh reality. 73 de N3RHT From jtml at losalamos.com Wed Nov 5 01:35:59 2014 From: jtml at losalamos.com (John Lyles) Date: Tue, 04 Nov 2014 23:35:59 -0700 Subject: [AMRadio] Tektronix repair In-Reply-To: References: Message-ID: <5459C54F.3080102@losalamos.com> Hey Jim, My experience is with a 7623 or one of the similar mainframes. Had a problem but was a bear to get to. They didn't build those scopes for easy take apart. Layers on top of layers of circuitry with tiny coax and ribbon cables plugged into fragile connectors. I eventually gave up, and scrapped it for parts. Long before, I took on a 465 that had an issue, and found it was similarly tough to get down to the board level. I think there were some ICs that were custom made, big things, for horizontal deflection, etc. So when they failed, it was worthless. Anyway, unlike the advice I saw in replies, I would not suggest trying to repair one unless you have the original manual, plenty of time and patience, and willing to give up when you cannot go any further. Best of 73s John Lyles K5PRO Santa Fe County, NM > > ------------------------------ > > Message: 7 > Date: Mon, 3 Nov 2014 21:06:35 -0600 > From: "Jim Wilhite" > To: "AM Radio List" > Subject: Re: [AMRadio] Tektronix repair > Message-ID: <703E562998224E15B7F3B79C254439CE at JimPC> > Content-Type: text/plain; format=flowed; charset="UTF-8"; > reply-type=response > > Thanks for the suggestions guys. But (a big word), the scope I have in mind > is a 485 and I am sort of attached to it and have the cart for it. I > believe it is a 350 Mc scope and works fine other than the traces do not > respond to the position control properly. I really can't tell you why I > want it fixed but just thought if I could find someone, I would do it. > > As for repairing things now a days, it is difficult Mike. I have trouble > keeping from burning wires in my Champion or King. Not only that my eyes > are not what they were even a year ago. Believe me it is hell getting old > but it is sort of fun, but not in cases like this. I do have the manuals > for it but have trouble with reading it. > > Tnx and 73 guys > > Jim > W5JO > > -----Original Message----- > > > Not to play pile on, but I have done repairs on many of Tektronix equipment. > If you have the service manual, then you are in shape to fix it yourself. At > least in my opinion, Tek manuals were the best in the business. I used to > repair their old copiers, printers, plotters, scopes, digital terminals etc. > If I were you, I would take a shot at it myself. > > Mod-U-Lator, > Mike(y) > W3SLK > > -----Original Message----- > > > > Unless you are a collector who wants a working vintage scope, the chances of > this being economical are slim and none. You can almost certainly go buy a > good working scope for less than the repair cost of the ones you have. It's > a 2014 harsh reality. > > 73 de N3RHT > > > > > > ------------------------------ > > Subject: Digest Footer > > ______________________________________________________________ > 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 > > > ------------------------------ > > End of AMRadio Digest, Vol 130, Issue 1 > *************************************** > From ranchorobbo at gmail.com Wed Nov 5 05:52:50 2014 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Wed, 5 Nov 2014 04:52:50 -0600 Subject: [AMRadio] Tektronix repair In-Reply-To: <5459C54F.3080102@losalamos.com> References: <5459C54F.3080102@losalamos.com> Message-ID: You can try google with your scope model and make and what is wrong: Tek 485 intermittent widget or whatever it is, and see if anything comes up. I do that frequently and sometimes wind up looking at web forums I didn't know existed where someone had the same problem and got useful help. Of course there can also be bad advice so you have to be able to discriminate but I've been able to connect some dots that way and get lucky at times. 73 Rob K5UJ From w5jo at brightok.net Wed Nov 5 11:06:00 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Wed, 5 Nov 2014 10:06:00 -0600 Subject: [AMRadio] Tektronix repair In-Reply-To: <5459C54F.3080102@losalamos.com> References: <5459C54F.3080102@losalamos.com> Message-ID: Hi John, How is everything in the mountains? I sure miss that climate. This problem is a trace location problem. The position knobs won't move them as they should and I am hoping against hope that it may be a simple fix. I have reached the point that small, delicate connectors and such are a real problem. That is why I am looking to see if anyone can fix it rather than myself. To give you an idea as to how things are for me, I also have a 2230 that I managed to blow the horizontal trace circuit. I was working on something and dropped the probe which went into the HV buss and boom. I do have a parts unit for that one but would rather have the 485 if possible. My guess is both may be headed for the parts heap like me. 73, Jim -----Original Message----- Hey Jim, My experience is with a 7623 or one of the similar mainframes. Had a problem but was a bear to get to. They didn't build those scopes for easy take apart. Layers on top of layers of circuitry with tiny coax and ribbon cables plugged into fragile connectors. I eventually gave up, and scrapped it for parts. Long before, I took on a 465 that had an issue, and found it was similarly tough to get down to the board level. I think there were some ICs that were custom made, big things, for horizontal deflection, etc. So when they failed, it was worthless. Anyway, unlike the advice I saw in replies, I would not suggest trying to repair one unless you have the original manual, plenty of time and patience, and willing to give up when you cannot go any further. Best of 73s John Lyles K5PRO Santa Fe County, NM > > ------------------------------ > > Message: 7 > Date: Mon, 3 Nov 2014 21:06:35 -0600 > From: "Jim Wilhite" > To: "AM Radio List" > Subject: Re: [AMRadio] Tektronix repair > Message-ID: <703E562998224E15B7F3B79C254439CE at JimPC> > Content-Type: text/plain; format=flowed; charset="UTF-8"; > reply-type=response > > Thanks for the suggestions guys. But (a big word), the scope I have in > mind > is a 485 and I am sort of attached to it and have the cart for it. I > believe it is a 350 Mc scope and works fine other than the traces do not > respond to the position control properly. I really can't tell you why I > want it fixed but just thought if I could find someone, I would do it. > > As for repairing things now a days, it is difficult Mike. I have trouble > keeping from burning wires in my Champion or King. Not only that my eyes > are not what they were even a year ago. Believe me it is hell getting old > but it is sort of fun, but not in cases like this. I do have the manuals > for it but have trouble with reading it. > > Tnx and 73 guys > > Jim > W5JO > > -----Original Message----- > > > Not to play pile on, but I have done repairs on many of Tektronix > equipment. > If you have the service manual, then you are in shape to fix it yourself. > At > least in my opinion, Tek manuals were the best in the business. I used to > repair their old copiers, printers, plotters, scopes, digital terminals > etc. > If I were you, I would take a shot at it myself. > > Mod-U-Lator, > Mike(y) > W3SLK > > -----Original Message----- > > > > Unless you are a collector who wants a working vintage scope, the chances > of > this being economical are slim and none. You can almost certainly go buy a > good working scope for less than the repair cost of the ones you have. > It's > a 2014 harsh reality. > > 73 de N3RHT > > > > > > ------------------------------ > > Subject: Digest Footer > > ______________________________________________________________ > 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 > > > ------------------------------ > > End of AMRadio Digest, Vol 130, Issue 1 > *************************************** > ______________________________________________________________ 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 From w5jo at brightok.net Tue Nov 11 17:36:43 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Tue, 11 Nov 2014 16:36:43 -0600 Subject: [AMRadio] Tube shield Message-ID: <7C41A1B8C32B4D078766D86C8FC8CAFC@JimPC> Does anyone have a tube shield that will fit a 6CL6? I need one with the bayonet base. Does not have to have the spring. I am not sure but thing the 12BY7 shield is the same????? Jim W5JO From ne1s at securespeed.us Wed Nov 12 07:25:02 2014 From: ne1s at securespeed.us (Larry Szendrei) Date: Wed, 12 Nov 2014 07:25:02 -0500 Subject: [AMRadio] Tube shield In-Reply-To: <7C41A1B8C32B4D078766D86C8FC8CAFC@JimPC> References: <7C41A1B8C32B4D078766D86C8FC8CAFC@JimPC> Message-ID: <5463519E.5020808@securespeed.us> On 11/11/14 5:36 PM, Jim Wilhite wrote: > Does anyone have a tube shield that will fit a 6CL6? I need one with the bayonet base. Does not have to have the spring. I am not sure but thing the 12BY7 shield is the same????? > > Jim > W5JO > Jim, I see no reason why a shield for the 12BY7 should not also work for the 6CL6. You want one of those black heat-dissipating shields with the corrugated inserts, as these tubes get hot in normal service. A garden-variety plain steel shield will reflect too much of the heat back to the tube, and/or not dissipate it to the environment at a high enough rate. 73, -Larry/NE1S From ranchorobbo at gmail.com Tue Nov 18 05:56:20 2014 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Tue, 18 Nov 2014 04:56:20 -0600 Subject: [AMRadio] Lightning detector Message-ID: Well we don't have to worry about lightning up here now when it is 3 degrees outside, but this gadget got my attention when it was mentioned in a broadcaster magazine. Not wild about gadgets normally, especially since most have a monthly bleed fee, but this seems to be (surprisingly) like the old days, a gadget you pay for once and use. Acurite lightning detector: http://www.acurite.com/lightning-detector-02020.html Anyone ever used one of these things? Might be nice in summer when roaming around the QTH and not checking a computer. 73 Rob K5UJ From w3slk at verizon.net Tue Nov 18 06:27:50 2014 From: w3slk at verizon.net (w3slk at verizon.net) Date: Tue, 18 Nov 2014 06:27:50 -0500 Subject: [AMRadio] Lightning detector In-Reply-To: References: Message-ID: <2F55EF71A4084355BC8D272D9EDCB4EE@MikeyPC> Rob, I got one similar to that when I purchased my weather station years ago. I got more false reports on it to the point it couldn't be trusted. I'm not sure if the technology has changed but looking at the price, I would say not. I don't know how much of a Luddite you are, but if you do happen to own a smart phone, Weather Bug has an app imbedded that detects lightning with almost deadly accuracy. $44 for a safety item? I don't think I would put a lot of stock into it. But that is just my opinion. Mod-U-Lator, Mike(y) W3SLK -----Original Message----- From: Rob Atkinson Sent: Tuesday, November 18, 2014 5:56 AM To: Discussion of AM Radio in the Amateur Service Subject: [AMRadio] Lightning detector Well we don't have to worry about lightning up here now when it is 3 degrees outside, but this gadget got my attention when it was mentioned in a broadcaster magazine. Not wild about gadgets normally, especially since most have a monthly bleed fee, but this seems to be (surprisingly) like the old days, a gadget you pay for once and use. Acurite lightning detector: http://www.acurite.com/lightning-detector-02020.html Anyone ever used one of these things? Might be nice in summer when roaming around the QTH and not checking a computer. 73 Rob K5UJ ______________________________________________________________ From ranchorobbo at gmail.com Tue Nov 18 12:31:50 2014 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Tue, 18 Nov 2014 11:31:50 -0600 Subject: [AMRadio] Lightning detector In-Reply-To: <2F55EF71A4084355BC8D272D9EDCB4EE@MikeyPC> References: <2F55EF71A4084355BC8D272D9EDCB4EE@MikeyPC> Message-ID: Mike thanks--I think this works better though. No "smartphone" here--no interest in the monthly bleed fee and no time to spend on yet another gadget. Life is too short for gadgets. 73 Rob K5UJ On Tue, Nov 18, 2014 at 5:27 AM, wrote: > Rob, > I got one similar to that when I purchased my weather station years > ago. I got more false reports on it to the point it couldn't be trusted. > I'm not sure if the technology has changed but looking at the price, I > would say not. I don't know how much of a Luddite you are, but if you do > happen to own a smart phone, Weather Bug has an app imbedded that detects > lightning with almost deadly accuracy. $44 for a safety item? I don't think > I would put a lot of stock into it. But that is just my opinion. > > Mod-U-Lator, > Mike(y) > W3SLK > > -----Original Message----- From: Rob Atkinson > Sent: Tuesday, November 18, 2014 5:56 AM > To: Discussion of AM Radio in the Amateur Service > Subject: [AMRadio] Lightning detector > > > Well we don't have to worry about lightning up here now when it is 3 > degrees outside, but this gadget got my attention when it was mentioned in > a broadcaster magazine. Not wild about gadgets normally, especially since > most have a monthly bleed fee, but this seems to be (surprisingly) like the > old days, a gadget you pay for once and use. > > Acurite lightning detector: > http://www.acurite.com/lightning-detector-02020.html > > Anyone ever used one of these things? Might be nice in summer when > roaming around the QTH and not checking a computer. > > 73 > > Rob > K5UJ > ______________________________________________________________ > > > From w5jo at brightok.net Tue Nov 18 16:36:34 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Tue, 18 Nov 2014 15:36:34 -0600 Subject: [AMRadio] Something strange Message-ID: About 2-3 years back I replaced the electrolytic caps in a Globe Champion on which I was doing an electrical restoration. I used Sprague Atom caps in the set, the bias circuit and the low voltage circuit. The low voltage runs about 300 volts and I used a 450 volt capacitor. In the bias circuit I used 350 volt capacitors where the voltage is about 100 volts. I have been using the set off and on since restoration and last week it suddenly developed a lot of hum on the carrier. That was with the audio off so it was a puzzle. I found one of the 350 volt filter capacitors in the bias circuit has opened. Not only that, the one in the Low Voltage supply had opened as well. The two caps were in different lots and I formed them with a TO 6 before installation. If I did a value check, they checked the proper value, but when I did the leak test they started out fine but quickly developed an open. All voltages were in specification and replacing them fixed the problem. I thought it strange two would go at the same time in different circuits and am a bit puzzled by it. Oh well it gave me something to do for a few days. Jim W5JO From pulsarxp at embarqmail.com Tue Nov 18 17:19:34 2014 From: pulsarxp at embarqmail.com (L L bahr ) Date: Tue, 18 Nov 2014 17:19:34 -0500 (EST) Subject: [AMRadio] Something strange In-Reply-To: Message-ID: <1596261801.5218327.1416349174850.JavaMail.root@embarqmail.com> How old were the caps when you first put them in there, Jim? If they were old to begin with, that might be your problem. Caps dry out with age. Lee, w0vt About 2-3 years back I replaced the electrolytic caps in a Globe Champion on which I was doing an electrical restoration. I used Sprague Atom caps in the set, the bias circuit and the low voltage circuit. The low voltage runs about 300 volts and I used a 450 volt capacitor. In the bias circuit I used 350 volt capacitors where the voltage is about 100 volts. I have been using the set off and on since restoration and last week it suddenly developed a lot of hum on the carrier. That was with the audio off so it was a puzzle. I found one of the 350 volt filter capacitors in the bias circuit has opened. Not only that, the one in the Low Voltage supply had opened as well. The two caps were in different lots and I formed them with a TO 6 before installation. If I did a value check, they checked the proper value, but when I did the leak test they started out fine but quickly developed an open. All voltages were in specification and replacing them fixed the problem. I thought it strange two would go at the same time in different circuits and am a bit puzzled by it. Oh well it gave me something to do for a few days. Jim W5JO From amradio at mailman.qth.net Tue Nov 18 17:41:36 2014 From: amradio at mailman.qth.net (Bill Guyger via AMRadio) Date: Tue, 18 Nov 2014 22:41:36 +0000 (UTC) Subject: [AMRadio] Something strange In-Reply-To: References: Message-ID: <1199880740.1475167.1416350496802.JavaMail.yahoo@jws100208.mail.ne1.yahoo.com> Jim I?think Lee is onto something. Sprague Atoms are still around (except they're Vishay Sprague now.....?another foreign buy out of America)?but if they've been?sitting around?in a goodie box for years I don't know that I'd trust them. I found a NOS?stash of?"old time"?Spragues?at the KTCK transmitter site, but am?leery of them...... Bill AD5OL ? From: Jim Wilhite To: AM Radio List Sent: Tuesday, November 18, 2014 3:36 PM Subject: [AMRadio] Something strange About 2-3 years back I replaced the electrolytic caps in a Globe Champion on which I was doing an? electrical restoration.? I used Sprague Atom caps in the set, the bias circuit and the low voltage circuit.? The low voltage runs about 300 volts and I used a 450 volt capacitor.? In the bias circuit I used 350 volt capacitors where the voltage is about 100 volts. I have been using the set off and on since restoration and last week it suddenly developed a lot of hum on the carrier.? That was with the audio off so it was a puzzle.? I found one of the 350 volt filter capacitors in the bias circuit has opened.? Not only that, the one in the Low Voltage supply had opened as well.? The two caps were in different lots and I formed them with a TO 6 before installation.? If I did a value check, they checked the proper value, but when I did the leak test they started out fine but quickly developed an open.? All voltages were in specification and replacing them fixed the problem. I thought it strange two would go at the same time in different circuits and am a bit puzzled by it.? Oh well it gave me something to do for a few days. Jim W5JO ______________________________________________________________ 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 From w5jo at brightok.net Tue Nov 18 18:37:44 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Tue, 18 Nov 2014 17:37:44 -0600 Subject: [AMRadio] Something strange In-Reply-To: <1596261801.5218327.1416349174850.JavaMail.root@embarqmail.com> References: <1596261801.5218327.1416349174850.JavaMail.root@embarqmail.com> Message-ID: <2D9A51847DA64175A9831AC4AE301DDA@JimPC> I ordered them just before installation. Now I can't tell anyone how long the supplier (Mouser) had them in stock, but they were new to me. Jim W5JO -----Original Message----- How old were the caps when you first put them in there, Jim? If they were old to begin with, that might be your problem. Caps dry out with age. From Tonne at Comcast.net Tue Nov 18 19:33:49 2014 From: Tonne at Comcast.net (Jim Tonne) Date: Tue, 18 Nov 2014 19:33:49 -0500 Subject: [AMRadio] Something strange In-Reply-To: <2D9A51847DA64175A9831AC4AE301DDA@JimPC> References: <1596261801.5218327.1416349174850.JavaMail.root@embarqmail.com> <2D9A51847DA64175A9831AC4AE301DDA@JimPC> Message-ID: <546BE56D.6000907@Comcast.net> Jim: Look at the code date invariably stamped on them. Year and week. - JimT W4ENE On 11/18/2014 6:37 PM, Jim Wilhite wrote: > I ordered them just before installation. Now I can't tell anyone how > long the supplier (Mouser) had them in stock, but they were new to me. > Jim > W5JO > > -----Original Message----- > > How old were the caps when you first put them in there, Jim? If they > were old to begin with, that might be your problem. Caps dry out with > age. > > ______________________________________________________________ > 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 > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4765 / Virus Database: 4189/8594 - Release Date: 11/18/14 > > From amradio at mailman.qth.net Tue Nov 18 19:43:01 2014 From: amradio at mailman.qth.net (Mel Farrer via AMRadio) Date: Wed, 19 Nov 2014 00:43:01 +0000 (UTC) Subject: [AMRadio] Something strange In-Reply-To: <546BE56D.6000907@Comcast.net> References: <546BE56D.6000907@Comcast.net> Message-ID: <99224797.826050.1416357781660.JavaMail.yahoo@jws10732.mail.gq1.yahoo.com> Just as a point,? a company called:? JUSTRADIO has a great catalog for old radio equipment.? Take a look. Mel, K6KBE From: Jim Tonne To: amradio at mailman.qth.net Sent: Tuesday, November 18, 2014 4:33 PM Subject: Re: [AMRadio] Something strange Jim: Look at the code date invariably stamped on them.? Year and week. - JimT W4ENE On 11/18/2014 6:37 PM, Jim Wilhite wrote: > I ordered them just before installation.? Now I can't tell anyone how > long the supplier (Mouser) had them in stock, but they were new to me. > Jim > W5JO > > -----Original Message----- > > How old were the caps when you first put them in there, Jim?? If they > were old to begin with, that might be your problem.? Caps dry out with > age. > > ______________________________________________________________ > 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 > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4765 / Virus Database: 4189/8594 - Release Date: 11/18/14 > > ______________________________________________________________ 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 From w5jo at brightok.net Tue Nov 18 20:14:02 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Tue, 18 Nov 2014 19:14:02 -0600 Subject: [AMRadio] Something strange In-Reply-To: <546BE56D.6000907@Comcast.net> References: <1596261801.5218327.1416349174850.JavaMail.root@embarqmail.com><2D9A51847DA64175A9831AC4AE301DDA@JimPC> <546BE56D.6000907@Comcast.net> Message-ID: Hi Jim, I am looking at the date code, 1148. Now that I think about it, I ordered by part number and wonder if they were left on the shelf or what. They are standard values and could have been stock. The strange thing about it is, in all my years I have never had Sprague fail like this, if the were the same value then I could better understand. These were manufactured in the US to boot and have been stored inside so the climate was not prone to temperature extremes. Oh well from now on I will put any electrolytic on the tester and leave it for several hours. Total operating time on these two was about 3 hours. Jim, W5JO -----Original Message----- Jim: Look at the code date invariably stamped on them. Year and week. - JimT W4ENE From Tonne at Comcast.net Tue Nov 18 20:30:08 2014 From: Tonne at Comcast.net (Jim Tonne) Date: Tue, 18 Nov 2014 20:30:08 -0500 Subject: [AMRadio] Something strange In-Reply-To: References: <1596261801.5218327.1416349174850.JavaMail.root@embarqmail.com><2D9A51847DA64175A9831AC4AE301DDA@JimPC> <546BE56D.6000907@Comcast.net> Message-ID: <546BF2A0.2090201@Comcast.net> Jim JO: 48th week of 2011. Those should be fine. - Jim W4ENE On 11/18/2014 8:14 PM, Jim Wilhite wrote: > Hi Jim, > > I am looking at the date code, 1148. From w5jo at brightok.net Tue Nov 18 20:47:56 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Tue, 18 Nov 2014 19:47:56 -0600 Subject: [AMRadio] Something strange In-Reply-To: <546BF2A0.2090201@Comcast.net> References: <1596261801.5218327.1416349174850.JavaMail.root@embarqmail.com><2D9A51847DA64175A9831AC4AE301DDA@JimPC> <546BE56D.6000907@Comcast.net> <546BF2A0.2090201@Comcast.net> Message-ID: <1804F05DDD2F4B3CACC427707BE3228E@JimPC> That is why I made the original post Jim. I have been around this stuff as an amateur since 1955 and, commercially from 1977 till 2004, but never saw a coincidence like this. Oh well live and conquer. 73 Jim W5JO -----Original Message----- Jim JO: 48th week of 2011. Those should be fine. - Jim W4ENE On 11/18/2014 8:14 PM, Jim Wilhite wrote: > Hi Jim, > > I am looking at the date code, 1148. From amradio at mailman.qth.net Tue Nov 18 20:56:07 2014 From: amradio at mailman.qth.net (CL in NC via AMRadio) Date: Tue, 18 Nov 2014 17:56:07 -0800 Subject: [AMRadio] Something strange In-Reply-To: Message-ID: <1416362167.67359.YahooMailBasic@web160606.mail.bf1.yahoo.com> By any chance where the the first filter cap after the rectifier? Could be a peak to peak ripple issue Charlie W4MEC in NC. From w5jo at brightok.net Tue Nov 18 21:09:37 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Tue, 18 Nov 2014 20:09:37 -0600 Subject: [AMRadio] Something strange In-Reply-To: <1416362167.67359.YahooMailBasic@web160606.mail.bf1.yahoo.com> References: <1416362167.67359.YahooMailBasic@web160606.mail.bf1.yahoo.com> Message-ID: I don't think so Charlie, I can't find evidence of that. The low voltage is choke input, the bias is cap, resistor, cap. The only thing I can think of is some sort of spike sometime that played havoc. I live in a rural area and one never knows. My line monitor does not show problems though. Jim W5JO -----Original Message----- By any chance where the the first filter cap after the rectifier? Could be a peak to peak ripple issue Charlie W4MEC in NC. ______________________________________________________________ From ne1s at securespeed.us Wed Nov 19 07:26:02 2014 From: ne1s at securespeed.us (Larry Szendrei) Date: Wed, 19 Nov 2014 07:26:02 -0500 Subject: [AMRadio] Something strange In-Reply-To: <1416362167.67359.YahooMailBasic@web160606.mail.bf1.yahoo.com> References: <1416362167.67359.YahooMailBasic@web160606.mail.bf1.yahoo.com> Message-ID: <546C8C5A.3020909@securespeed.us> On 11/18/14 8:56 PM, CL in NC via AMRadio wrote: > By any chance where the the first filter cap after the rectifier? Could be a peak to peak ripple issue > > Could be. I had a recurring problem with electrolytics repeatedly failing in a the low voltage supply in my Viking Ranger. The power supply was not stock, because the original power transformer had failed (I never owned the Ranger when the original power xfmr was present, so I've never ieven seen it.) Instead the power transformer was from an old tube-typed TV, with a silicon diode bridge around the HV secondary and low-voltage B+ taken from the center-tap of the winding. The high-voltage B+ went to a choke-input filter, but the low-voltage B+ was capacitor-input - simply a 450WVDC electrolytic in the 40-80uF range from the HV center-tap to ground. (I used several capacitors of different values in this range as they kept failing, and I replaced them with whatever I had on hand. The original low-voltage filter choke was also missing from the rig.) The failure mode was always open, or high series resistance. I finally eliminated the problem by installing a replacement choke from the junkbox to make the low-voltage B+ supply filter choke-input, like the rig originally used, and like the high-voltage B+ supply. This was probably over 10 years ago, and I have not had a failure since. I had to conclude it was a peak voltage or peak current problem killing the capacitors. I had used many different brands of capacitors, both modern and NOS, all failed eventually before I added the choke. Also, I have had experiences of modern off-shore manufactured electrolytics overheating and letting their smoke out, sometimes spectacularly, when used as replacements on the input side of a conventional pi capacitor-input filter in high-voltage supplies. I started using Nichicons and have not experienced this since. YMMV. 73, -Larry/NE1S From james.liles at comcast.net Wed Nov 19 11:11:19 2014 From: james.liles at comcast.net (james.liles at comcast.net) Date: Wed, 19 Nov 2014 10:11:19 -0600 Subject: [AMRadio] Something strange In-Reply-To: <546C8C5A.3020909@securespeed.us> References: <1416362167.67359.YahooMailBasic@web160606.mail.bf1.yahoo.com> <546C8C5A.3020909@securespeed.us> Message-ID: <402ADF88BE944172B66B4BCA3DF8EE8E@LILESJLAPTOP> Try a 100 ohm resistor in series from the low voltage diode stack to the capacitors. Should take care of the capacitor problem and reduce the ripple. Kindest regards Jim K9AXN -----Original Message----- From: Larry Szendrei Sent: Wednesday, November 19, 2014 6:26 AM To: amradio at mailman.qth.net Subject: Re: [AMRadio] Something strange On 11/18/14 8:56 PM, CL in NC via AMRadio wrote: > By any chance where the the first filter cap after the rectifier? Could > be a peak to peak ripple issue > > Could be. I had a recurring problem with electrolytics repeatedly failing in a the low voltage supply in my Viking Ranger. The power supply was not stock, because the original power transformer had failed (I never owned the Ranger when the original power xfmr was present, so I've never ieven seen it.) Instead the power transformer was from an old tube-typed TV, with a silicon diode bridge around the HV secondary and low-voltage B+ taken from the center-tap of the winding. The high-voltage B+ went to a choke-input filter, but the low-voltage B+ was capacitor-input - simply a 450WVDC electrolytic in the 40-80uF range from the HV center-tap to ground. (I used several capacitors of different values in this range as they kept failing, and I replaced them with whatever I had on hand. The original low-voltage filter choke was also missing from the rig.) The failure mode was always open, or high series resistance. I finally eliminated the problem by installing a replacement choke from the junkbox to make the low-voltage B+ supply filter choke-input, like the rig originally used, and like the high-voltage B+ supply. This was probably over 10 years ago, and I have not had a failure since. I had to conclude it was a peak voltage or peak current problem killing the capacitors. I had used many different brands of capacitors, both modern and NOS, all failed eventually before I added the choke. Also, I have had experiences of modern off-shore manufactured electrolytics overheating and letting their smoke out, sometimes spectacularly, when used as replacements on the input side of a conventional pi capacitor-input filter in high-voltage supplies. I started using Nichicons and have not experienced this since. YMMV. 73, -Larry/NE1S ______________________________________________________________ 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 From Tonne at Comcast.net Wed Nov 19 11:23:37 2014 From: Tonne at Comcast.net (Jim Tonne) Date: Wed, 19 Nov 2014 11:23:37 -0500 Subject: [AMRadio] Something strange In-Reply-To: <402ADF88BE944172B66B4BCA3DF8EE8E@LILESJLAPTOP> References: <1416362167.67359.YahooMailBasic@web160606.mail.bf1.yahoo.com> <546C8C5A.3020909@securespeed.us> <402ADF88BE944172B66B4BCA3DF8EE8E@LILESJLAPTOP> Message-ID: <546CC409.60701@Comcast.net> Jim K9AXN: A poor-man's filter choke! Definitely worth a try. - JimT W4ENE On 11/19/2014 11:11 AM, james.liles at comcast.net wrote: > Try a 100 ohm resistor in series from the low voltage diode stack to > the capacitors. Should take care of the capacitor problem and reduce > the ripple. > > Kindest regards Jim K9AXN From w5jo at brightok.net Wed Nov 19 19:05:03 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Wed, 19 Nov 2014 18:05:03 -0600 Subject: [AMRadio] [AM Radio] Something strange Message-ID: You guys have some good thoughts on this. A couple of things I did not mention. The transformer output is rectified by a 5U4 and has a 50 K bleeder resistor across the output. The CT is lifted above ground to kill the voltage in standby. Everything is standard 1955 and should not have this trouble. This circuit is a choke input with a single capacitor filter with the bleeder across it, but the bias is cap, resistor, cap. This full wave low voltage is really a mystery to me, and given the failure of another cap of different value bought at the same time makes me wonder if there was a bad run and I managed to get two of them. The bias circuit is 110 volts rectified by a Selenium (replaced by a silicon diode, 1N4007) and previous sets like this that I restored never had a problem with them. So I have different caps in it now and will try it. I have checked the choke and diodes along with associated tubes and other parts and found nothing that should cause the trouble. The transformer is a recent rewind with a 125 volt primary (Don't ask how that happens to be). Thanks all and I will watch it out of the case for a number of hours and if nothing happens, it will go into the case. If something does, I will put a 100 ohm resistor in the appropriate place and hope that does it. Larry, these Sprague were marked Made in the US. Motorola used to buy offshore parts and assemble pagers in this country so they could say Made in the US, I don't know if that is what happened in this case or not, but nothing would surprise me. Thanks guys, Jim W5JO P.S. Pardon me Larry for sending this to you two times. -----Original Message----- On 11/18/14 8:56 PM, CL in NC via AMRadio wrote: > By any chance where the the first filter cap after the rectifier? Could > be a peak to peak ripple issue > > Could be. I had a recurring problem with electrolytics repeatedly failing in a the low voltage supply in my Viking Ranger. The power supply was not stock, because the original power transformer had failed (I never owned the Ranger when the original power xfmr was present, so I've never ieven seen it.) Instead the power transformer was from an old tube-typed TV, with a silicon diode bridge around the HV secondary and low-voltage B+ taken from the center-tap of the winding. The high-voltage B+ went to a choke-input filter, but the low-voltage B+ was capacitor-input - simply a 450WVDC electrolytic in the 40-80uF range from the HV center-tap to ground. (I used several capacitors of different values in this range as they kept failing, and I replaced them with whatever I had on hand. The original low-voltage filter choke was also missing from the rig.) The failure mode was always open, or high series resistance. I finally eliminated the problem by installing a replacement choke from the junkbox to make the low-voltage B+ supply filter choke-input, like the rig originally used, and like the high-voltage B+ supply. This was probably over 10 years ago, and I have not had a failure since. I had to conclude it was a peak voltage or peak current problem killing the capacitors. I had used many different brands of capacitors, both modern and NOS, all failed eventually before I added the choke. Also, I have had experiences of modern off-shore manufactured electrolytics overheating and letting their smoke out, sometimes spectacularly, when used as replacements on the input side of a conventional pi capacitor-input filter in high-voltage supplies. I started using Nichicons and have not experienced this since. YMMV. 73, -Larry/NE1S From ranchorobbo at gmail.com Thu Nov 20 05:51:22 2014 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Thu, 20 Nov 2014 04:51:22 -0600 Subject: [AMRadio] [AM Radio] Something strange In-Reply-To: References: Message-ID: The CT is lifted above ground to kill > the voltage in standby. Everything is standard 1955 and should not have > this trouble. > > I don't understand how lifting the CT ground kills the B+ Rob K5UJ From amradio at mailman.qth.net Thu Nov 20 09:19:44 2014 From: amradio at mailman.qth.net (CL in NC via AMRadio) Date: Thu, 20 Nov 2014 06:19:44 -0800 Subject: [AMRadio] Liftin center tap to kill B+ Message-ID: <1416493184.87027.YahooMailBasic@web160606.mail.bf1.yahoo.com> Lifting the CT removes the return path. That rectified voltage has to get back to the xfmr some way, and the CT is it. An xfmr with no CT but using a bridge, the bridge swaps each end of the TX secondary to ground on each half cycle, where as a full wave CT only uses 1/2 the secondary on each half cycle. Charlie W4MEC in NC From ranchorobbo at gmail.com Thu Nov 20 10:20:24 2014 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Thu, 20 Nov 2014 09:20:24 -0600 Subject: [AMRadio] Liftin center tap to kill B+ In-Reply-To: <1416493184.87027.YahooMailBasic@web160606.mail.bf1.yahoo.com> References: <1416493184.87027.YahooMailBasic@web160606.mail.bf1.yahoo.com> Message-ID: Yeah but Jim says he has a full wave bridge. anyway, I'd check the voltage at the center tap when it is lifted. Nothing happens magically. There as to be a reason the caps blew. Rob K5UJ On Thu, Nov 20, 2014 at 8:19 AM, CL in NC via AMRadio < amradio at mailman.qth.net> wrote: > Lifting the CT removes the return path. That rectified voltage has to get > back to the xfmr some way, and the CT is it. An xfmr with no CT but using > a bridge, the bridge swaps each end of the TX secondary to ground on each > half cycle, where as a full wave CT only uses 1/2 the secondary on each > half cycle. > > 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 > From w5jo at brightok.net Thu Nov 20 10:41:44 2014 From: w5jo at brightok.net (Jim Wilhite) Date: Thu, 20 Nov 2014 09:41:44 -0600 Subject: [AMRadio] Liftin center tap to kill B+ In-Reply-To: References: <1416493184.87027.YahooMailBasic@web160606.mail.bf1.yahoo.com> Message-ID: No the circuit is a full wave rectifier as opposed to half wave which requires different handling and normally not used in HV circuits for transmitters. Jim W5JO -----Original Message----- Yeah but Jim says he has a full wave bridge. anyway, I'd check the voltage at the center tap when it is lifted. Nothing happens magically. There as to be a reason the caps blew. Rob K5UJ On Thu, Nov 20, 2014 at 8:19 AM, CL in NC via AMRadio < amradio at mailman.qth.net> wrote: > Lifting the CT removes the return path. That rectified voltage has to get > back to the xfmr some way, and the CT is it. An xfmr with no CT but using > a bridge, the bridge swaps each end of the TX secondary to ground on each > half cycle, where as a full wave CT only uses 1/2 the secondary on each > half cycle. > > Charlie W4MEC in NC From ne1s at securespeed.us Thu Nov 20 13:56:17 2014 From: ne1s at securespeed.us (Larry Szendrei) Date: Thu, 20 Nov 2014 13:56:17 -0500 Subject: [AMRadio] [AM Radio] Something strange In-Reply-To: References: Message-ID: <546E3951.9050803@securespeed.us> On 11/20/14 5:51 AM, Rob Atkinson wrote: > I don't understand how lifting the CT ground kills the B+ Rob K5UJ In a typical vacuum-tube full-wave rectified HV supply the CT of the HV secondary is the negative lead of the DC output. So letting the CT float breaks the circuit in the negative lead. Strictly speaking, it kills the B- ;-) 73, -Larry/NE1S From pete at zilliox.net Sun Nov 23 23:24:45 2014 From: pete at zilliox.net (pete zilliox) Date: Sun, 23 Nov 2014 20:24:45 -0800 Subject: [AMRadio] Collins 820D-2 AM Broadcast TX Schematic Message-ID: I have a manual (several found on Google Searches) but I can't find a schematic. However, I do have an entire schematic on an 8.5 x11 copy of a copy. I can't read most of the print. So, doesn't anyone have a schematic with a high definition quality soft copy that I could take to Kinkos to print on a large sheet of paper? Many thanks for any help you can offer. Best 73 Pete - K5PZ Huntington Beach, California

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