The primary source of information used to compile this summary comes from 'DH Support' in the form of the following 'Index of Modifications'. However, this document doesn't appear to be under any formal Document Management Control and shows some inconsistencies.
http://www.dhsupport.com/archives/Ch...ifications.pdf
The references provided from the RAF Pilots Notes (Amended to 1994) along with other information sources have been used in an attempt to catalogue the historic changes as they relate to the coms fit of the UK Mil Chipmunk. UK Civilian Chipmunk MOD history has been ignored.
OK chaps ... preamble out the way
Firstly, I will confirm that at no time was the combined V/Uhf PTR175 comms equipment ever fitted to the UK Mil Chipmunk.
The original 'production' coms specification was for a very basic (solitary) Vhf radio. This was in the form of either the TR1520 or TR1920 (10 Channel XTL controlled). These sets were designed and built very much based on post WWII (1947) technology. They were unreliable and were soon replaced. There is some evidence to suggest that a 'version' of the TR1520 (with only 4 Channel XTL controlled) was also installed. However, on the 170th and subsequent aircraft the slightly more reliable TR1934 (ARI15491) and TR1936 (ARI5489) radios were specified/installed.
TR1934
TR1936
The TR1936 was a 10 Channel (50 Khz Spacing) XTL controlled radio covering 115 Mhz to 145 Mhz producing about 8 Watts AM output.
The Vhf radio installation was then progressively upgraded over time with the TR198x series of equipment namely TR1985/6/7/8/9. These were far superior radios although physically similar to the early radios in terms of external appearance. Again 10 Channel (50 Khz Spacing) XTL controlled covering 100 Mhz to 156 Mhz (later Mks) producing about 10 Watts AM output.
TR1986 (Front Cover Removed)
More to follow ...