08-04-2013, 12:55 PM
OK, proceeding.
Restored the wire, got the voltages.
Populated the output, the driver and the 1st audio.
Got a bit scared of large voltages while measuring output.
Then I lowered the Variac, waited about 30 sec, touched the wiper of the volume and got the buzz.
Releazed the wiper, heard the noise.
Nice.
Then I realized that I have 1kOhm/V meter.
Believe it or not...NO DIFFERENCE!!!! DMM (FLUKE 189) or my MX-815 B/U...within the tolerance both show the same.
Now, I put the voltage to 110V, waited 'till the noise appeared...all voltages then fell exactly in the range shown in the chart. 290V at the output, 225V at the driver. Again, no difference when using DMM or 1kOhm/V meter.
Then again, 1kOhm/V at the 500V scale makes it 500 kOhm load which is fairly small, 0.5mA at these voltages.
So I guess for big radios where the currents are large, especially at the audio stage where there are no resistors in series with B+, it does not matter what one uses for measurements.
OK, so WE ARE BUZZING AND HISSING!!!
Nice.
Restored the wire, got the voltages.
Populated the output, the driver and the 1st audio.
Got a bit scared of large voltages while measuring output.
Then I lowered the Variac, waited about 30 sec, touched the wiper of the volume and got the buzz.
Releazed the wiper, heard the noise.
Nice.
Then I realized that I have 1kOhm/V meter.
Believe it or not...NO DIFFERENCE!!!! DMM (FLUKE 189) or my MX-815 B/U...within the tolerance both show the same.
Now, I put the voltage to 110V, waited 'till the noise appeared...all voltages then fell exactly in the range shown in the chart. 290V at the output, 225V at the driver. Again, no difference when using DMM or 1kOhm/V meter.
Then again, 1kOhm/V at the 500V scale makes it 500 kOhm load which is fairly small, 0.5mA at these voltages.
So I guess for big radios where the currents are large, especially at the audio stage where there are no resistors in series with B+, it does not matter what one uses for measurements.
OK, so WE ARE BUZZING AND HISSING!!!
Nice.