[Premium-Rx] RA6790/GM ISB board

[Thomas Adams]

Greetings.

I'm looking for those of you on the list that have, and / or have
installed, the optional ISB board in the RA6790/GM. I especially
want to talk to those who have the crystal filters with the board,
rather than the mechanical filters.

After over a year of searching I managed to get my hands on 
the board, and it has been sitting here waiting for the necessary
seperate LSB and USB filters. Last week I got a pair of the 
crystal filters (Racal #8409 and #8410) on EBAY; they're on
thier way now.

Most ISB Racals I've seen seem to use the Collins mech filters, 
and from the sources I spoke to in my search I found that most 
folks have never even SEEN the crystal filters, even tho on paper
at least the crystal filters would give better audio recovery than
the mechanical filters.

When a pair of crystals unexpectedly popped up, I didn't hesitate.

The manual information on the board & filters seems pretty
straightforward, but it seems that NOTHING is as simple as
it first seems.

If anyone out there knows of any tips, or any GOTCHAs to be
avoided in this installation, please let me know. 


73's,


Tom, W9LBB