Hello. Merry Xmas to all of you. Still need some help on my 2-B that still on the bench.
I have calibrated the S-Meter using the manual instructions. The radio was turned on for a long time BTW. The process was straightforward. Too bad that even a 15Mohm voltmeter shunts the AVC line. The manuals procedure takes this in account. Later I realized that when I turned the radio on again, the S-meter did not go to S1 right away. This is what happens: When I turn on the 2-B, the S-meter goes to around S9+10 and then goes down to S8. Then it starts a process that takes around 10 minutes until it goes to S1 (to the calibrated position). I have verified the whole AVC circuit (resistors and capacitors). The AVC is working apparently well. It acts, as it should. I have also replaced the 6BF6 (AVC amplifier). Nothing changes this behavior. I also realized that there is a slight change on the S meter S1 when the AVC is set from fast to slow (or vice versa). On Slow the S meter goes closer to S2. When the resting process is happening, I tried to monitor the AVC2 voltage with the VTVM or with an oscilloscope, but the measurement instruments load difficult the task and even changes the S-meter position. I do not think it has to do with heat because sometimes I turn the receiver off for few minutes and turn it on and all happens once again. I am wondering if someone have experimented that and/or has any tip. Thanks and regards Fred _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
