The AM Forum

I left my 6790 hooked to an antenna whilst operating a high power TX....It still plays but the sensitivity is way down...This happened once before and I sent the first mixer card to Gary Wingerd for repair......I can't find Gary anymore.(is he still doing Racal repair?)  It looks like he replaced a 16 pin chip on the antenna input...I read SP1 50001 and 80 44 printed on the chip..If this is the problem,I can replace the chip if I can find one..  I would appreciate any advice on this RX repair...Thanx..Steve KL7OF

There is a Racal Yahoo Group which at least a few years ago had traffic on this subject and I believe Gary is/was a member.  If you search the back traffic from the 2007-2009 era this was a popular subject.

As you point out, the front end of the 6790 is as robust as a canary and even precipitation static can blow it out as it was originally supplied.  These were never intended to be hooked directly to an antenna (so I was told) but rather were intended to be downstream from a multicoupler.  Common suggestions today are to feed the set from something like an Ameco preamp just to insert a buffer between antenna and receiver.

Working from memory, there is a generic part you can use for that chip, and some precautions you can take to protect the front end, by adding.  What those were, I don't remember - - neon lamps, back to back diodes, ?

I rec'd several replies to this query...Thank you...I was able to contact Gary Wingerd and ordered  a new SD50001 chip assy. If I can get it installed properly, I will be happy...

I rec'd the chip and pc board mounting card from Gary .......Installed it yesterday....Receiver works as it should......