Picked up bunch of 19 Set stuff

[Mike K]

Originally Posted by Bruce Parker

There are a lot of little differences, usually things added to the later Mk.III. The biggest difference is that the Mk.II has a noisy electric motor providing the required voltages and it runs all the time. The Mk.III has the same noisy motor that kicks in when you transmit or need it but otherwise runs on a quietly humming vibrator.

I believe the British made Mk111 power supply has two small genemotors , one for receive and one for transmit , these are mounted one above the other .

I did have a Canadian Mk111 power unit with the vibrator unit for receive mode , it had the 12 pin socket