Thanks Garey, well the meter seems OK, the DMM on lowest resistance range causes it to deflect a tad. I had to repair the AVC switch at one point, I guess I should check there, among other places.
Chuck, K1OM On Feb 6, 2008 4:20 PM, Garey Barrell <[EMAIL PROTECTED]> wrote: > > Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist > gang > ---------------------------------------------------------------------- > Chuck - > > The S-Meter is a simple bridge circuit that compares the plate current > of V2 and V3 with the plate current of V4 and V5. There are only two > resistors and two trim-pots! Since the radio seems to be working more > or less normally, those tubes are probably "good enough". If the meter > needle is just sitting there on the mechanical zero point, it's most > likely an "open" in that circuitry. Just as a guess, I'd first check > the meter terminal connections, then wonder about the S-Meter > Sensitivity pot, but it could be a bad connection or (YIKES!) an open > meter movement. The movement itself is 3 mA, as are ALL the R-4/T-4 > meters, so can be checked with a DMM for continuity. Don't try to use a > VOM, as they put too much current through the ohmmeter circuit. > > 73, Garey - K4OAH > Glen Allen, VA > > Drake 2-B, 4-B & C-Line Service Supplement CDs > <www.k4oah.com> > > > > Chuck Grandgent wrote: > > R4A, S-meter was working OK, just noticed it is not right now, don't > > know for quite how long. > > > > AVC is working, as evidenced by turning RF gain all the way down and > > then back up, AVC slow takes very noticeably longer for the RF leve to > > return once I turn up RF gain, compared to AVC fast. > > > > Adjusting R40 and R42 for S-meter and balance have zero effect, > > S-meter is all the way to the left. > > > > Things to try ? > > > > Tnx, Chuck, K1OM > > > > > > ---------------------------------------------------------------------- > Submissions: [EMAIL PROTECTED] > Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body > Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net > ---------------------------------------------------------------------- >
