PCMA001 -01

[yaggiboom]

I'm sure someone has come across this updated version of the PCMA001S board. It has -01 at the end of the ID No. It is used in the Nato 2000, Tristar 747, 848, Lafayette LMS230, 2400, Superstar 2200.............etc. It has a few but significant differences to the layout and components. Switch transistors Q3 and Q9 are no longer on the board, or the silkscreen locators. They are replaced with D61 and D62 steering diodes.

More significantly is the replacement of Q19 in the first mixer, from a NPN transistor C2839 or C2724 with a 3SK107e MOSFET. This is also found in the PCMA002F UK FM board used in the Amstrad etc radio's. Coils L4, 5, 6, 7, and 25 in the offset crystal circuit have been replaced with resistors

The schematic will have changed and if anyone has got a copy I would be very grateful if I could have one

[Mitch]

If you have a look at the ham multi 3/concorde 3/jumbo 3 circuit ptbm133a4x, that uses a fet for the first mixer but it's q17 there. It's in the cybernet service manual available online if you haven't got a copy. Is that similar?

[yaggiboom]

You're correct. All the changes are also present in the 133 circuit. It also looks like Q36 on the PCMA board has been replaced with a 7808 voltage reg.