[Icom] IC-756

[Greg Ordy]

Tony, VE6CGX wrote:

>>>> That IR opto chopper has to be in alignment because it uses two pulses.

Sadly, the encoder in the 756, the PRO, the PRO 2, and I
suspect many other recent vintage ICOM radios uses a
magnetic disk as opposed to an optical chopper. If it were
an optical chopper, fixing and cleaning might be much
easier (and cheaper). The magnetic disk contains approximately 250 individual
magnets that pass by a coil which senses the movement.
The encoder case contains the disk, the coil, and a PC
board with several ICs and trimmers. 

I once got involved with trying to find a cheaper source for the
ICOM encoder, which was $130 in the US. For some reason,
it is much cheaper in Europe. Go figure.

The whole thing blew up in my face, and was one of my
bigger and better follies. You can read about it on the following
web page:


http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/IC756%20Encoder.htm

    Greg Ordy, W8WWV