In message , Gazz writes
I have taken the 40 way channel selector switch out of an old CB radio,
and want to see if i can figure out how it works, with a view of using
it on my computer (i need 10 switch detents over a 90 degree arc for a
control lever, hence the 40 switch detents over 360 degrees of the CB
switch gives me what i want when i use a quarter of a turn on it)

The switch is made by uniden, and has the following markings on it...
SR-334, P-79 2-5A, they are stamped in, the UNIDEN word is cast in the
back plate as well as 'PSS-23'

i apeers to be made up of 4 x wafers, each individual wafer has 5 pins,
and they are stacked front to back, i.e. there's room for 6 pins, but
one is missing giving 2 space 3 pins, then the next wafer is 3 space 2
pins and repeat.

that gives a total of 20 pins,

i'm going to play with the multimeter on it, but wondered if anyone
knew how they work internaly,

i need to make it work like a 2 bit gray scale rotary encoder, know how
to do that with a single pole rotary switch where there's an obvious 1
common pin and the switched pins (uses a few diodes to give the A, B,
AB, 0, A, B AB etc output) but can i do that with this switch?

In the 1980s, I modified a few UK CB sets for use at the top end of the
amateur 10m band. Most designs used a limited variety of dedicated
synthesiser ICs - the LC7317 being a typical example (the intention
being to make it difficult to move them off the original CB
frequencies), and the channel was selected by a binary coded decimal
address. The channel selection switch was designed to provide the
appropriate address directly. However, I don't really have any immediate
access to any further useful information.
--
Ian

Ian Jackson wrote:
In message , Gazz writes
I have taken the 40 way channel selector switch out of an old CB
radio, and want to see if i can figure out how it works, with a view
of using it on my computer (i need 10 switch detents over a 90 degree
arc for a control lever, hence the 40 switch detents over 360 degrees
of the CB switch gives me what i want when i use a quarter of a turn
on it)

The switch is made by uniden, and has the following markings on it...
SR-334, P-79 2-5A, they are stamped in, the UNIDEN word is cast in
the back plate as well as 'PSS-23'

i apeers to be made up of 4 x wafers, each individual wafer has 5
pins, and they are stacked front to back, i.e. there's room for 6
pins, but one is missing giving 2 space 3 pins, then the next wafer is
3 space 2 pins and repeat.

that gives a total of 20 pins,

i'm going to play with the multimeter on it, but wondered if anyone
knew how they work internaly,

i need to make it work like a 2 bit gray scale rotary encoder, know
how to do that with a single pole rotary switch where there's an
obvious 1 common pin and the switched pins (uses a few diodes to give
the A, B, AB, 0, A, B AB etc output) but can i do that with this switch?

In the 1980s, I modified a few UK CB sets for use at the top end of the
amateur 10m band. Most designs used a limited variety of dedicated
synthesiser ICs - the LC7317 being a typical example (the intention
being to make it difficult to move them off the original CB
frequencies), and the channel was selected by a binary coded decimal
address. The channel selection switch was designed to provide the
appropriate address directly. However, I don't really have any immediate
access to any further useful information.

Fairly sure that there are logic chips to turn the sorts of outputs that
might give to whatever you want. Or use a PIC/ATMEL etc and a few lines
of code..