04-19-2014, 08:42 AM
Stinkkin intermittents! If anyone has ever dealt with one of these, you know what I mean! Anyways, I still have a volume coming and going issue. Thought I had it traced to the tuner HF trimmer - not. I've had to (more or less) table to project for now, and will be real hit or miss over the next few months as to how much I can get done as I am now 'owned' by my job for the season. About the only chances I will have will be a rainy Sunday afternoon.
I have spent quite a bit of time tracing things out, thinking the problem may be around the 1st detector area. I disabled the osc by removing the 27 tube, and have been connecting the gen at IF freq' to the grids of the different tubes up to the 1st af/2nd det. I get the most noted effect from the 1st det grid, and RF tube. Seems those two tubes work back and forth (one affects the other and vice a versa. ) It is difficult to tell since I think I hear some change no matter where I inject the signal, but it is most noted in this area. Could be that if a tube current is changing (due to a bad connection) it will effect others on down the line. I havent pulled the RF tube yet to run checks without it in the circuit.
All coils check, tubes swapped around, resistors, voltages, etc. One issue in trying to check things is checking plate voltages - kills the signal, then I cant tell if it is acting up when I am watching voltages.
I think I am down to resoldering connections and taking bakelites back out in the area to check my work. Any thoughts?
I have spent quite a bit of time tracing things out, thinking the problem may be around the 1st detector area. I disabled the osc by removing the 27 tube, and have been connecting the gen at IF freq' to the grids of the different tubes up to the 1st af/2nd det. I get the most noted effect from the 1st det grid, and RF tube. Seems those two tubes work back and forth (one affects the other and vice a versa. ) It is difficult to tell since I think I hear some change no matter where I inject the signal, but it is most noted in this area. Could be that if a tube current is changing (due to a bad connection) it will effect others on down the line. I havent pulled the RF tube yet to run checks without it in the circuit.
All coils check, tubes swapped around, resistors, voltages, etc. One issue in trying to check things is checking plate voltages - kills the signal, then I cant tell if it is acting up when I am watching voltages.
I think I am down to resoldering connections and taking bakelites back out in the area to check my work. Any thoughts?
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
