Hi Chris
My mistake the other valve is a VR136 not VR138 the unit is a bit
tarnished, strange that transmitting valve is there? I can't believe
its a transmitter, or transmits in any way, there is no change over and
the controls and connections are real simplicity, it looks like a
straightforward simple HF receiver? Anyway thanks for the info, I guess
by the lack of replies its an unusual one
cheers
from Ron...


Chris Suslowicz wrote:
"ron_ayling" wrote:

Hi, I've recently purchased what looks like an old Ex WD unit, with no
identity plates, and I'd really like to identify it, I'm sure its a
receiver though it could be a converter of some description, quite
large front panel 280 by 170mm 300mm deep, centre left of the front
panel are three controls marked Aerial RF and Oscillator, each having a
little window that clicks round 0 to 9, to the right is a paxolin
panel with test points marked V1 to V10, bottom of panel sockets left
to right marked RF input, Output, Power Input, Gain control, inside the
three front panel controls connect to what looks like a front end box
which held two valves marked VR138 and VR137, there are then six IF
cans with a single coil inside and six valve holders alongside marked
VR65...

With those valves, it's ex-RAF, probably late WW2 to 1950s vintage.

VR137 is an EC52 low power VHF transmitting triode on B9G base.
VR138 is unlisted in anything I have to hand, unfortunately.
VR65 is an SP61 pentode (100MHz max frequency) on Maxda Octal base.

The EC52 is capable of 7 watts and 300MHz, so it's a transceiver
or transponder of some sort, I'd guess. (Possibly IFF?)

Hope this is some help,

Chris.