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
