07-06-2015, 12:41 PM
That one was a PITA. Wired up the filters and a few stray wires to there appropriate places fired it up and it blew out the 25Z5. After a few more 25Z5's we figured we got us a short in the B+(not in the FC side). Started unsoldering the B+ wires to find it and found it at the IF transformer. Fixed that. Now it was playing but had a nasty 60cy hum and it was modulating the audio. So add 40uf to the filtering and it helped a little. Added more bypassing to the 1st audio and IF amp. Did nothing. Changed out all of the toobs to make sure there wasn't a leaky cathode/grid somewhere. Did nothing. Bypassed the plate of the 75 to B- that helped a lot but still has a fair amount of hum. Now that I've been thinking about it it could be the grid resistor on the 75 is open. This set runs the audio wide open and adjusts the volume by the amount of RF it allows down the ant. It's pretty cramped under the chassis and a PITA to work on.
The other sets when quick. Bad spkr, miswired cap, and figure out what tubes go in this chassis. The barking dog forum gave Kirk the wrong ID for the chassis so when he pulled up the schematic it didn't match. Got it sorted out and when it got back home (abt 9pm) I found the proper model and schematic for it.
A good time was had by all! Kirk is a gracious host kept me well fed and and full of beverage. House looks great too!
Terry
The other sets when quick. Bad spkr, miswired cap, and figure out what tubes go in this chassis. The barking dog forum gave Kirk the wrong ID for the chassis so when he pulled up the schematic it didn't match. Got it sorted out and when it got back home (abt 9pm) I found the proper model and schematic for it.
A good time was had by all! Kirk is a gracious host kept me well fed and and full of beverage. House looks great too!
Terry