[Premium-Rx] Racal RA1772

[Michael O'Beirne]

Gents

In amplification of Pat's comments, tonight, I might mention that I once met 
one of the designers of the RA1772 at the RSGB's annual VHF rally at Sandown 
Park about 20 years or more ago.  I seem to recollect that the poor chap was 
going through a divorce and selling kit (presumably to keep the lawyers 
happy!).

His part was the design of the complex wiring harness.  If you have not seen 
one in pristine order, it is, believe me, a thing of much beauty.

At the time I was not aware of the heat issue and did not tackle him on it, 
and I do not suppose at the manufacturing time Racal were either, otherwise 
they could presumably have used PTFE cabling for not much additional cost.

He said Racal nearly went bonkers trying to get the wiring right to avoid 
cross-coupling unwanted signals.  Each set was tuned by hand from zero to 
30MHz to check on the spurii, and "adjustments" made.  This is not the way 
to make a cheap product and keep accountants happy.

The RA1792's wiring is pedestrian and cheap in contrast, but it has to be 
said in fairness that it works, albeit that the microprocessor board should 
have been properly screened and decoupled, as it is in the replacement, the 
RA37xx series.

73s
Michael
G8MOB