09-20-2016, 09:35 PM
OK Terry (and anyone else who is better at this than I am), hang with me on this...
I have the "new" power transformer installed from the model 16 parts chassis. I'm getting a 3 to 4 amp current draw and the sound becoming somewhat garbled as the set plays a few minutes. One of the 42 audio output's (the one closest to the outside of the chassis) gets a lot hotter and brighter than the one right next to it. In checking voltages, on both 42 audio output tubes, P to K I'm getting 288 / 300 volts and it should be 190. Way too high. The 42 driver tube, which should also read 190, is low. It reads 160 P to K.
In trying to isolate where the draw is coming from, I removed the rectifier tube and brought it up to 120VAC on the variac. Of course I get no draw. Zero.
Then I reinstalled the rectifier and removed both 42 audio output tubes. Again at 120 VAC I have only 1 amp of AC draw.
With only one #42 audio output tube in (the inside socket), at 120 VAC I get 2 amps draw. Switching this #42 to the outside socket (the one that was running hot), I'm back to 3 amps draw.
Leaving both audio output tubes in, and just removing the #42 driver tube, I'm pushing 4 amps draw at 120 VAC.
I'm probably confusing you as to why I'm wasting my time or having you shake your head in bewilderment right about now
But I'm trying to take a logical approach to try to isolate the area where the draw first starts occurring. If, based on what I'm finding, you have any thoughts or ideas as to where to look first (the link to the schematic is on page one of this thread), I would be most deeply appreciative. I checked all of my solder joints and did not find anything amiss.
I have the "new" power transformer installed from the model 16 parts chassis. I'm getting a 3 to 4 amp current draw and the sound becoming somewhat garbled as the set plays a few minutes. One of the 42 audio output's (the one closest to the outside of the chassis) gets a lot hotter and brighter than the one right next to it. In checking voltages, on both 42 audio output tubes, P to K I'm getting 288 / 300 volts and it should be 190. Way too high. The 42 driver tube, which should also read 190, is low. It reads 160 P to K.
In trying to isolate where the draw is coming from, I removed the rectifier tube and brought it up to 120VAC on the variac. Of course I get no draw. Zero.
Then I reinstalled the rectifier and removed both 42 audio output tubes. Again at 120 VAC I have only 1 amp of AC draw.
With only one #42 audio output tube in (the inside socket), at 120 VAC I get 2 amps draw. Switching this #42 to the outside socket (the one that was running hot), I'm back to 3 amps draw.
Leaving both audio output tubes in, and just removing the #42 driver tube, I'm pushing 4 amps draw at 120 VAC.
I'm probably confusing you as to why I'm wasting my time or having you shake your head in bewilderment right about now
But I'm trying to take a logical approach to try to isolate the area where the draw first starts occurring. If, based on what I'm finding, you have any thoughts or ideas as to where to look first (the link to the schematic is on page one of this thread), I would be most deeply appreciative. I checked all of my solder joints and did not find anything amiss.
Greg V.
West Bend, WI
Member WARCI.org
