In message , Nigel M
writes
I've got two pairs of Pye Pocketfone 9 Series Transmitters & Receivers.
I want to put them on eBay, but I don't really know much about them.

They used to be used for studio talkback in a Commercial TV Studio in SE
London,
ITN used to use them as talkback many years ago.

but were replaced in a recent refurbishment. For security
purposes, the crystals have been unplugged, but I have managed to
acquire eight of them. The crystals are all colour coded green (as are
the 9Rs) and have values 470.1 470.2 and 470.4 - presumably MHz.

Please note that if by "crystals" you mean the plug in cube at the
bottom then this is more than just the crystal. The crystal is inside
this unit, without the plug in they are not much use. One BIG word of
advice is if you have the TX apart do NOT touch the PCB while it is
powered up as this can cause the PSU inverter to go over volt and blow
all sorts of interesting things!

I'd almost forgotten about PF9s, I used to make them many years ago.



Can anyone give me any more info? Are these of use to radio amateurs?

If you want short range simplex or live near a repeater they are great,
one advantage is that the RX had an RF sensor that would detect the TX
and mute the RX to stop feed back. There is also an earpiece socket on
the top, if you look closely two of the speaker holes are slightly
different and these take a two pin plug, as used on many pro' earpieces.
--
Bill