Hello Aerial
Thanks for the heads up for the STR37E radio, I did manage to find one in the end on a vintage radio forum.
I am still after the amplifier unit which fits in a cradle in the nose of the helicopter. Apparently when this 6W amplifier was fitted to the STR37E it makes it an STR38, which caused some initial confusion.
Here is my radio and the cradle missing its amplifier which would of measured 9.5cms across and 32cms in length.

[ATTACH=CONFIG]224093[/ATTACH][ATTACH=CONFIG]224094[/ATTACH][ATTACH=CONFIG]224095[/ATTACH]

So if anyone has one of these 1960’s Standard Telephone and Cables 6W amplifier units please let me know.
Regards and a happy new year
Simon.