Working on a JL1000. The outputs have 2 mica heatsink insulators strips stacked on top of each other. , where all other heatsink mounted components (rectifiers and PS fets) only have one. Is that by design? or a mistake somewhere down the line?
It could be either. Sometimes, the output FETs have thicker insulators to help reduce the coupling of high frequencies to the heatsink.
The only time that you can reasonably believe that it was a mistake is when there is no heatsink compound between the two insulators.
The only time that you can reasonably believe that it was a mistake is when there is no heatsink compound between the two insulators.
Re-soldered the 10 pin connector on the pre-amp board and it seems to have solved the intermittent loss of drive on the low power supply fet. If I wiggled the preamp board on the remote-in area the fet would lose drive signal and get a flat 5vdc drive (which is what probably destroyed the fet in the first place).
For the JL 1000, you almost always need a battery. The low-voltage protection is very sensitive. None of my power supplies alone can supply clean enough voltage to allow high power testing. If you use a battery, you MUST use a fuse. A 60-80 amp fuse in addition to to your power supply may be good enough.