[Elecraft] K2 vs K1 for strong station resistance?

[Tom Hammond]

Hi Peter:

At 12:30 PM 7/8/03, Peter Wollan wrote:
>This Field Day, I set up my K1 to get the solar-power bonus for our club
>(W0MXW), and tried it on several bands.  Had fairly minimal success in
>getting heard, probably because of the antenna, but I was surprised at
>how seriously it was affected by the nearby QRO stations.  If any of the
>other stations (kilowatt or 100-watt) was transmitting on the same band,
>even way at the other end, the K1's receive was muted and distorted, to
>the point of making copy difficult.  The various antennas were not
>oriented to reduce interference -- I'm sure that would have been
>helpful.
>
>My questions:  Is this just a fact of life for radios, that you can only
>have one radio per band at a FD setup (if it's QRO)?  Is it a limitation
>of the K1, or maybe my K1?  And, is the K2 enough better in this respect
>that it could reasonably be expected to be used on, say, 20m CW while a
>nearby kilowatt station is on 20m SSB?

Front End Overload  (FEO)can be a fact of life in such 'close-spaced' 
operations.

At our N0SS/0 FD operations(for years) we always had problems when two 
stations were on the same band.

Then, when I began bringing my K2 to FD (about 3-4 years ago) our front end 
overload on the CW (K2) station dropped substantially, and we (the CW 
station) were able to co-exist with the SSB station on the same band, BUT 
we still had some problems when the Novice/Tech station was on the same 
band (also CW) as well. Additionally, the other two (non-K2) rigs continued 
to suffer from FEO as before.

THEN... in a fit of brilliance (I won't divulge who thought of it, out of 
humility), we decided to align the three 80/40M dipoles of our stations 
NORTH-TO-SOUTH _AND_ IN A STRAIGHT LINE (end-to-end) with the ends of any 
two adjacent dipoles separated by about 50'-60'. This put the signal null 
off the the end of each dipole in a position so it caused the least amount 
of RF from RIG #1 getting into the front end of RIGs #2 & #3.

  <--N--    |---------|      |---------|      |---------|
              80M/40M    60'   80M/40M    60'   80M/40M

The results were astounding! We can now literally run all three rigs (one 
CW at the bottom of the band, one CW mid-band, and the SSB station) on the 
same band with little or no FEO!!! Of course, this assumes all three rigs 
are on 80 or 40M _AND_ that all three are using the dual-band dipole 
available to them. Of course, if one station switches to the vertical, then 
all bets are off, since there's no usable null available any longer.

There has been am ovement afoot to consider using 5-band dipoles next year 
and not even worrying about verticals OR beams. If this goes thru, I think 
we may actually be able to coexist on ANY band.

73,

Tom  N0SS