Topband: SSB splatter problems during contest

[gary nichols]

>         Ken, we should always be operating using properly adjusted
> equipment...CW and SSB.  One interesting thing I noticed this weekend
> was some very bad S9+20 splatter below 1825.  It must have been coming
> from a station well up the band because I could not find a fundamental
> signal to correlate it with nearby.

Hi Bill,

It was coming from a station in Virginia on 1912kHz. It took nearly
a half-hour to find him!

He was only 20 over 9 on 1912, and 10 over on 1820-24! That's why
he was so hard to find.
73, Tom W8JI

I had a similar problem at this station about 15years ago.  It was being
caused in my Ten-Tec CorsairII by too much RF energy coming into the rig
through the aux antenna input (beverage connection) on the back of the rig.
The problem is that most if not all commercially available transceivers with
a "receive antenna input" (receive only)separate from the main antenna in an
UNPROTECTED INPUT.  By that I mean it is NOT disabled during transmit.  The
end effect is like a PA system turned up too high!!! You can't hear the
feedback but it can either cause a bad case of spurious transmission or if
bad enough can destroy the receiver front-end.  Many rigs have been sent
back to the factory for repair of this.  Some two or three times!!  Ten-Tec
suggested adding a relay controlled by the keying circuit of the transmitter
and even sent me parts to do it with.
    This promped me to design and build the "front-end-saver" which can be
found in CQ magazine Feb 1997.
You may not need anything this complex, but something to mute that input
during transmit.  Perhaps W8JI can explain the mixing action that occurs in
a typical rig that will cause this problem.  Sorry for being so windy but
this has been a very real problem since transceivers have existed.  Luck to
all and much DX....de gary, kd9sv