05-15-2012, 02:31 PM
This thing is ticking me off. Lets start from the beginning. When I first rewound the coil I wound the secondary in a CW direction from the common point and the primary in a CCW direction. No oscillation. Attaching a 4.7K resistor across the 6K, as suggested, did nothing.
Removed the coil and found a cut in the secondary and repaired it. Rewound the primary in a CW direction, even gave it 2 extra turns, and retried. Still nothing. Tacked in the 4.7K resistor and still nothing. The "gimmick" is in place and the wiring is correct.
I do have noise/squeal, whatever, thru the speaker as I bring finger close to the grid of the 77 second detector. I just tried sending a 460KC thru the radio with the generator set on high output using a AM loop placed close to the chassis and nothing. Checking the IF transformer shows all connections/ continuity is good.
Using a transistor radio I tried checking for an oscillator with the transistor radio set around 700KC and turning the tuning cap of the Philco. Nothing. I've already gone trhu and resoldered all connections including redoing all the ground connections off of the tube socket rivots and the B+ is good. All caps and resistors have been replaced.
I got my 77 tubes from a fellow ARF'er and they checked good on my tube tester. I even tried swapping them around in the radio and that proved pointless. I did ask for a picture of the underside of the chassis which I was kindly supplied but now that I actually pay attention to it the picture shows that all the tube sockets have been replaced with octals so who knows what the actual wiring should look like.
I'm kinda stuck here and need a good clear picture of the underside of an umolested 84 to compare with and also any advice of what to try next.
Removed the coil and found a cut in the secondary and repaired it. Rewound the primary in a CW direction, even gave it 2 extra turns, and retried. Still nothing. Tacked in the 4.7K resistor and still nothing. The "gimmick" is in place and the wiring is correct.
I do have noise/squeal, whatever, thru the speaker as I bring finger close to the grid of the 77 second detector. I just tried sending a 460KC thru the radio with the generator set on high output using a AM loop placed close to the chassis and nothing. Checking the IF transformer shows all connections/ continuity is good.
Using a transistor radio I tried checking for an oscillator with the transistor radio set around 700KC and turning the tuning cap of the Philco. Nothing. I've already gone trhu and resoldered all connections including redoing all the ground connections off of the tube socket rivots and the B+ is good. All caps and resistors have been replaced.
I got my 77 tubes from a fellow ARF'er and they checked good on my tube tester. I even tried swapping them around in the radio and that proved pointless. I did ask for a picture of the underside of the chassis which I was kindly supplied but now that I actually pay attention to it the picture shows that all the tube sockets have been replaced with octals so who knows what the actual wiring should look like.
I'm kinda stuck here and need a good clear picture of the underside of an umolested 84 to compare with and also any advice of what to try next.
