Quote:
Originally Posted by jr_tech
Yes, I am using the on-line schematic... somewhat hard to read, but the 2 tuner schematics (pages 15 & 16) are pretty clear. I expand the picture as necessary on this iPad. The varicap diodes are fairly easy to locate, just follow the lines from the "tuning" input(s) of each tuner down to the 33k isolation resistors to the VC diodes.
I have no idea how to check them or how to find replacements. 
jr |
Ok I got them I just took 2 of them out its like brain surgery . I read to test them like a regular diode so I checked the 2 out of 4 and I get a reading one way but the other way I get a reading but only momentary then nothing. I'm wondering if one is bad will I shut down the oscillator which is where they are along with transistors. I don't know if getting a momentary reading may mean they are leaking. Oh and they have numbers, mpn3404. Do you know which is the vhf tuner , would it be the smaller case ?