Shackleton AEW

Hi All

I need information please on the VHF radios fitted to the Shack AEW ( and lots of other service aircraft of the 70,s ) the PTR 175 (???).

Circuit diagrams, handbooks, Schematics etc, would be VERY handy.

My background is MK 1,s 2,s Phase 1, the mid 50s with ASWDU at St Mawgan.

Can anyone help please?

Shackman 123