From ne1s at securespeed.us Wed Nov 1 07:25:36 2017 From: ne1s at securespeed.us (Larry Szendrei) Date: Wed, 1 Nov 2017 07:25:36 -0400 Subject: [AMRadio] [Glowbugs] Re: [AWA] Tek 535/545 vertical amp calibration question In-Reply-To: <18bf6df9-2fe8-9345-1400-7c0bcc3378b0@aafradio.org> References: <6297b473-5152-61b0-95da-1e1b1500e953@securespeed.us> <18bf6df9-2fe8-9345-1400-7c0bcc3378b0@aafradio.org> Message-ID: <8c5b1906-1106-4908-38e8-ab51ff4a2754@securespeed.us> On 10/28/17 12:26 PM, Michael Hanz wrote: > Just make one - it seems pretty simple: > https://groups.io/g/TekScopes/topic/951626?p=,,,20,0,0,0::,,,0,0,0,951626 > > On 10/28/2017 9:41 AM, Larry Szendrei ne1s at securespeed.us > [antiquewirelessassociation] wrote: >> >> I wonder if anyone has any tips for how to calibrate the vertical >> amplifier on a Tektronics 535 and/or 545 oscilloscope without the EP53A >> Gain Set Adaptor called for in the manuals' procedure? >> A final note on this topic that may prove helpful to anyone who needs to calibrate the vertical amp on one of these fine old, but beastly, instruments: Using the information in the link that Mike provided (see above), I was able to take one channel of a spare, unused type CA dual-trace plug-in I had and convert it to calibrate the vertical amps in both my 535A and RM45 'scopes. One input of the plug-in now bypasses its amplifier and accepts a signal from the internal calibrator to set the sensitivity of the mainframe vertical amplifier to 100mv/cm. After calibrating the mainframe amp I calibrated the plug-ins (two more type CAs and one type K). After (and despite) the repair/maintenance dose to the scopes, which in the case of the RM45 was quite extensive, the calibrations weren't that far off. 73, -Larry/NE1S From k4kyv at charter.net Thu Nov 16 17:09:20 2017 From: k4kyv at charter.net (Donald Chester) Date: Thu, 16 Nov 2017 16:09:20 -0600 Subject: [AMRadio] History of AM power proceeding now viewable on FCC website Message-ID: <001101d35f27$8d507560$a7f16020$@charter.net> Facts in the case are laid out in chronological order, followed by supporting documentation that pre-dates FCC archives (which extend only back to 1992). This should make it easy for those not thoroughly familiar with this case to discover and understand the past agenda of those in power at the FCC at that time, and how this has affected use of the AM mode in amateur radio. This was submitted in response to a public enquiry announced by the FCC's Office of Engineering and Technology Technological Advisory Council (TAC), seeking comments about technical regulations and the regulatory process used for adopting and updating them. Part 1: Chronological timeline 1983-1990, Exhibits 1-9 https://ecfsapi.fcc.gov/file/11142326307940/17110802.pdf Part 2: Exhibits 10-16 https://ecfsapi.fcc.gov/file/11142326307940/17110802-2.pdf --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus From don.kd2fo at gmail.com Thu Nov 16 17:22:39 2017 From: don.kd2fo at gmail.com (Don Rasmussen) Date: Thu, 16 Nov 2017 17:22:39 -0500 Subject: [AMRadio] History of AM power proceeding now viewable on FCC website In-Reply-To: <001101d35f27$8d507560$a7f16020$@charter.net> References: <001101d35f27$8d507560$a7f16020$@charter.net> Message-ID: Hi, Just today I came upon an ARRL publication from 1970, entitled "Single Sideband for the Radio Amateur". It has an interesting article that explains AM PEP power correctly......which is NOT 4X Carrier as largely spoken of today.....and I can also prove it as an engineer. The article on page 9 of the 1970 SSB Manual is entitled "Why Single Sideband".....it contains a great explanation of Amplitude Modulation, with FULL carrier and illustrates it using Figures #1, #2, #3 contained in the article. I am not an expert on the FCC proceedings, and our AM legal limit does depend on FCC WORDINGS within part 97 as well as outright limitations, but couldn't my 2 cents worth because recent mis-understandings. I am willing to explain my position, but am hoping to write an article.....if someone will publish it. 73, Don, Kd2fo On Thu, Nov 16, 2017 at 5:09 PM, Donald Chester wrote: > Facts in the case are laid out in chronological order, followed by > supporting documentation that pre-dates FCC archives (which extend only > back to 1992). This should make it easy for those not thoroughly familiar > with this case to discover and understand the past agenda of those in power > at the FCC at that time, and how this has affected use of the AM mode in > amateur radio. > > > > This was submitted in response to a public enquiry announced by the FCC's > Office of Engineering and Technology Technological Advisory Council (TAC), > seeking comments about technical regulations and the regulatory process > used > for adopting and updating them. > > > > Part 1: Chronological timeline 1983-1990, Exhibits 1-9 > > https://ecfsapi.fcc.gov/file/11142326307940/17110802.pdf > > > > Part 2: Exhibits 10-16 > > https://ecfsapi.fcc.gov/file/11142326307940/17110802-2.pdf > > > > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > ______________________________________________________________ > 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 hro5-2 at cox.net Fri Nov 17 11:30:46 2017 From: hro5-2 at cox.net (Jim Hill) Date: Fri, 17 Nov 2017 08:30:46 -0800 Subject: [AMRadio] Test equipment In-Reply-To: References: Message-ID: <20171117163045.QRTG14996.fed1rmfepo101.cox.net@fed1rmimpo209.cox.net> My Heath capacitor tester has a leakage tester. The capacitance range selector is frozen, but the the leakage tester is very useful for reforming electrolytics. I like to not replace electrolytics until I get the equipment running and see where I stand. If you work on yours, check the resistors in the voltage range switch. Jim At 08:09 AM 8/20/2017, Ed via AMRadio wrote: >A recent search for a signal generator found one on Amazon with >pretty good reviews. > >My meager bench hosts a few bits of equipment that I use the most, >everything else being either too expensive or really just >superfluous. Things I couldn't do without: oscilloscope, frequency >counter, signal generator, analog multimeter ( an ancient Simpson) >and a grid dip meter. I have a heathkit capacitor checker, the type >that checks for leakage, but its down and out now. > >Whats your list of tools you cant live without? > >VR, Ed Mullin From k4kyv at charter.net Sat Nov 18 11:21:05 2017 From: k4kyv at charter.net (Donald Chester) Date: Sat, 18 Nov 2017 10:21:05 -0600 Subject: [AMRadio] Test equipment - Heathkit capacitor tester Message-ID: <000b01d36089$3c4e8040$b4eb80c0$@charter.net> > From: amradio-bounces at mailman.qth.net [mailto:amradio- > bounces at mailman.qth.net] On Behalf Of Jim Hill > > My Heath capacitor tester has a leakage tester. The capacitance range > selector is frozen, but the the leakage tester is very useful for reforming > electrolytics. I like to not replace electrolytics until I get the equipment > running and see where I stand. If you work on yours, check the resistors in > the voltage range switch. > Jim I use mine (pulled from a dumpster) primarily for the leakage test, which works very well for checking leakage as well as reforming electrolytics. The capacitance measurement is all but useless: very inaccurate, lucky to get within 50% so I never use that; I have my NEC digital capacitance meter which is accurate and with ranges down to a few pf. I sometimes use the leakage test as a low-current voltage source for up to 450 volts or so. Once a capacitor shows low leakage with the magic eye, I sometimes connect my DVM in the micro amp range, or a 50 micro amp panel meter, in series with the capacitor to measure the actual leakage current at the test voltage (risky if you are not careful). Don k4kyv --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus From ranchorobbo at gmail.com Sun Nov 19 18:22:24 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Sun, 19 Nov 2017 17:22:24 -0600 Subject: [AMRadio] Test equipment - Heathkit capacitor tester In-Reply-To: <000b01d36089$3c4e8040$b4eb80c0$@charter.net> References: <000b01d36089$3c4e8040$b4eb80c0$@charter.net> Message-ID: There's a cruder way to check for leakage that's more of a pass/fail method. with clip leads and a knife switch and VOM spread out on a bench run a clip lead from the + lug on the capacitor tester variable DC supply to one side of the spst knife switch and another clip lead from the other side of the switch to one lug of the cap under test. The free lug on the cap goes to the + terminal of the VOM set to measure next voltage scale above the maximum positive DC supply voltage and the minus lug on the VOM returns to the minus lug on the variable dc supply with a last clip lead. with knife switch open run the voltage up to near the maximum rating of the capacitor and drop the switch blade. The VOM should swing up to whatever that voltage is, and as the cap charges, drop down. If there's no leakage it should get to zero volts eventually. With leaky old oil caps it will drop down to around 10 or 20 volts and hang there. For comparison try the same test with a modern new 1 mfd polypropylene 600 v. cap. VOM will quickly swing down to zero. > I like to not replace electrolytics until I get the > equipment >> running and see where I stand. > One of the first things I do is cut out and toss out old paper wrapped and wax sealed electrolytics and replace them with new. I don't give them a chance to destroy a transformer by trying to get the equipment running with them in there. 73 Rob K5UJ From mjcal77 at yahoo.com Sun Nov 19 18:50:43 2017 From: mjcal77 at yahoo.com (CL in NC) Date: Sun, 19 Nov 2017 23:50:43 +0000 (UTC) Subject: [AMRadio] I hate Micamolds References: <649350706.1268864.1511135443350.ref@mail.yahoo.com> Message-ID: <649350706.1268864.1511135443350@mail.yahoo.com> Micamold caps have to be the best 'planned obsolescence' part ever made. These caps that can fool you as they look like a common postage stamp mica, always need to be checked. I have never found one that was not more resistor than capacitor. At least they are easy to spot as the proudly print their name somewhere on them. They are really just a wax cap in the postage stamp looking package. I am redoing a piece of gear full of Micamolds and purchased appropriate modern replacements. Now, your standard low value 'real' postage stamp micas seldom give me a problem and I didn't even bother to spot check any of those. Well, I discovered this unit has a bunch of .01 postage stamp style micas that I overlooked, and on the cap checker and ohm meter, they are leaking.... a bit. Now these are all in circuits with only 28VDC on them, and they show 100+meg, and short on the cap checker at around 75 volts, they are supposed to be a 300volt cap. These are all in bypass situations, no freq determining or coupling use. What is a consensus on changing all these out? 100+meg is plenty or 100+ meg is a leaker? 100+ meg on a screen circuit to ground fed through a 47K from B+ will not load the circuit down that much, but how effective a bypass cap will it be? Thanks for some thoughts on this. Charlie, W4MEC in NC From K4TQF at yahoo.com Sun Nov 19 19:38:55 2017 From: K4TQF at yahoo.com (Mike Durff) Date: Mon, 20 Nov 2017 00:38:55 +0000 (UTC) Subject: [AMRadio] Techicnal Inquiry Into Reforming Technical Regulations by Federal Communications Commission 24 OCT 2017 References: <1469267513.1143083.1511138335840.ref@mail.yahoo.com> Message-ID: <1469267513.1143083.1511138335840@mail.yahoo.com> I have made all 16 articles available in print at cost $7.07. ( cheaper than a printer cartridge ! ) 8 1/2" X 11" format, spiral bound, 102 pages. Techicnal Inquiry Into Reforming Technical Regulations by Federal Communications Commission 24 OCT 2017 (Paperback) - Lulu | | | Techicnal Inquiry Into Reforming Technical Regulations by Federal Communications Commission 24 OCT 2017 (Paperback) -... Buy Techicnal Inquiry Into Reforming Technical Regulations by Federal Communications Commission 24 OCT 2017 (Pap... | | | From ranchorobbo at gmail.com Sun Nov 19 22:16:26 2017 From: ranchorobbo at gmail.com (Rob Atkinson) Date: Sun, 19 Nov 2017 21:16:26 -0600 Subject: [AMRadio] I hate Micamolds In-Reply-To: <649350706.1268864.1511135443350@mail.yahoo.com> References: <649350706.1268864.1511135443350.ref@mail.yahoo.com> <649350706.1268864.1511135443350@mail.yahoo.com> Message-ID: There's a complex byzantine method for telling micamolds from real micas and I read it once in an email post to some boatanchor list, but I can't remember what I had for lunch Friday, and there's no way in the world I'll ever remember the fine points or dull points of mica disambiguation, so they all get shotgunned out if it's up to me and I move on. That method saves more time than repeated crapouts. 73 Rob K5UJ On Sun, Nov 19, 2017 at 5:50 PM, CL in NC via AMRadio wrote: > Micamold caps have to be the best 'planned obsolescence' part ever made. These caps that can fool you as they look like a common postage stamp mica, always need to be checked. I have never found one that was not more resistor than capacitor. At least they are easy to spot as the proudly print their name somewhere on them. They are really just a wax cap in the postage stamp looking package. I am redoing a piece of gear full of Micamolds and purchased appropriate modern replacements. Now, your standard low value 'real' postage stamp micas seldom give me a problem and I didn't even bother to spot check any of those. Well, I discovered this unit has a bunch of .01 postage stamp style micas that I overlooked, and on the cap checker and ohm meter, they are leaking.... a bit. Now these are all in circuits with only 28VDC on them, and they show 100+meg, and short on the cap checker at around 75 volts, they are supposed to be a 300volt cap. These are all in bypass situations, > no freq determining or coupling use. What is a consensus on changing all these out? 100+meg is plenty or 100+ meg is a leaker? 100+ meg on a screen circuit to ground fed through a 47K from B+ will not load the circuit down that much, but how effective a bypass cap will it be? Thanks for some thoughts on this. > >

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