1/13/2011 9:38:51 PMDaniel M.(92496:0)
Good evening,
I just recapped a Bulova, model 100, installed a new AC line cord, rechecked my work and powered the chassis on using a variac and 2 meters one to measure the AC input and one to measure the DC output on the output filter capacitor. The chassis powered on just fine. The problem is no audio output from the speaker. This radio played before I started the recap process. Had a hum but did play stations.
What would be the place to check now? I tested the 50C5 and showed a weak tube but radio should show some form of life I would think? Any idea, I would be very greatful!! Thank you all!!!
Daniel M.
1/13/2011 10:38:23 PMTerry Decker(92498:92496)
:Good evening,
: I just recapped a Bulova, model 100, installed a new AC line cord, rechecked my work and powered the chassis on using a variac and 2 meters one to measure the AC input and one to measure the DC output on the output filter capacitor. The chassis powered on just fine. The problem is no audio output from the speaker. This radio played before I started the recap process. Had a hum but did play stations.
:What would be the place to check now? I tested the 50C5 and showed a weak tube but radio should show some form of life I would think? Any idea, I would be very greatful!! Thank you all!!!
:Daniel M.
:
You forgot one elemental rule in replacing components- If you have a working radio always test it after EVERY substitution. Now you have to start troubleshooting at the beginning. I'm sure I don't have to remind you to look for solder globs on sockets, wires touching, etc. My guess is that you've accidentally switched wires someplace. I don't have the schematic, but a simple test is to start at the input grid of the output tube with a 'buzz' test, (a screwdriver or even unplugged soldering iron to generate a hum). Go back one stage at a time until the buzz stops. Your problem is in that stage.
Good luck and keep us posted.
Terry
1/14/2011 2:33:06 AMWarren(92511:92498)
Agree with Terry again. A lot of times an easy mistake to make is right there in the power supply. Do you have B+ on all the plates? A wire misplaced going to the audio output tube grid from power supply ?