[Racal] 6790 VLF

[Dan Rae]

Gary Wingerd posted some minimal information on this and other variants 
on the yahoo RA6790/GM reflector recently.  It will be in the archive, 
but it was mainly lists of CCA (board) numbers only.   Apart from a 
different first mixer board and firmware, the R2174B seems to have the 
usual A1 and A3 through A10 stuff plus a lot of extra boards, mostly to 
do with IF outputs, if I interpret his spreadsheet correctly.  The 
manual is apparently not available.  If certainly will not cover VHF as 
some have thought.

There is a civilian version of the RA6790/GM that has extended VLF 
coverage, I have one.  This has 6 Collins filters, and different A2 and 
A3 boards with among other things 8 kHz wide roofing filters, which as I 
found in the contest yesterday, make a big difference in a band crowded 
with strong signals :^)
 
I presumed Gordon had seen this yahoo stuff since he posted to the 
premium list a while back.
73
Dan
ac6ao / g3ncr