Hi Bob, Actually I was checking both. It was the resistance values which were extremely high and I was trying to make sure it wasn’t because of the meter I was using and I suppose it wasn’t.
When I get it reassembled, I can check voltages with something more appropriate. Thanks, Barry > On Sep 2, 2024, at 11:33 AM, Bob Camp <[email protected]> wrote: > > Hi > > Ok, I’m guessing we have a typo. > > We’re measuring voltage at the test points rather than resistances. Let’s > see, I’ve probably only made about 10 typo’s in this message so far … :) :) > > Some of the old VTVM’s had pretty crazy input impedances. It would a bit > unusual to find one that was above 10 Meg *and* something you would use in a > radio with hundreds of volts running around in it. > > Something like a Simpson 260 would be a much lower input impedance device > when set up for looking at test point voltages. Simple answer in this case, > grab that Simpson and see what it reads. > > Bob > >> On Sep 2, 2024, at 10:31 AM, Barry <[email protected]> wrote: >> >> Did Collins specify what input impedance a meter should be to properly read >> the resistance values in the manuals? I did see where a TS-352 was >> mentioned but that's selectable between 20,000 ohms/volt and 1,000 ohms/volt. >> >> I started checking the RF Deck in my R-390 and, starting with V201, I noted >> a few values that are significantly high. I was using a modern DMM with 10M >> input impedance so not sure if that could be the problem but I doubt it >> would account for that much difference but who knows. >> >> The voltages were off a bit as well but not nearly as much as the resistance >> values. I suspect the radio will still work with wacky voltages but the R >> values really have me thinking I have work to do. >> >> Thanks, >> Barry - N4BUQ >> ______________________________________________________________ >> R-390 mailing list >> Home: http://mailman.qth.net/mailman/listinfo/r-390 >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
