Hello Everyone,
I have picked up an Advance J1B audio generator at a garage sale that someone has attempted to repair previously. There is a tube missing, there are a number of wires cut, and there are burned resistors.
I wonder if anyone could help me out with schematics.
The generator is a tube based Wien-bridge circuit with a dual gang capacitor tuning. Interestingly, there is no bulb based stabilizer circuit, like in a HP generator. There are three frequency ranges from 15Hz to 150KHz, and it looks like that amplitude feed-back is also switched with the range. The generator has 5ohm and 600ohm outputs. The tube complement is an EC90, ECC88 (6DJ8), EZ81, and an EL84 (6BQ5) missing according to the scribbling on the panel. I only have 6GK6, which should be equivalent to the 6BQ5, except for pinout. I would like to bring back the generator to life as the reduction gear and the scale seems to be decent quality.
Thanks, Peter