[Elecraft] ARRL Field Day

[Bill Frantz]

The West Valley Amateur Radio Association field day operation 
was set up as it has been for the last few years on Mora Hill. 
Mora Hill is at an altitude of about 500' on the west side of 
the Santa Clara Valley, California. This year we were 9A SCV. We 
had 4 towers with various Uda-Yagi antennas for 20M, 15M, and 
10M with wire antennas for 40M and 80M.

On HF we were an all K3 operation and for the second year in a 
row experienced no mutual interference between our transmitters. 
We did set up our antennas in a line, all pointed at the east 
coast, so the side lobe rejection helped reduce interference. I 
was operating the digital station for most of the event and the 
only indication I had of other stations in our operation was a 
strong track on the P3 from our CW operation.

I did get significant interference from another field day 
operation. They were set up perhaps 1/4 mile away in the major 
lobe of our antennas using 100 watts. When I turned the RF gain 
down low enough to prevent overload from their signal it looked 
like a clean PSK signal, so I think the wide-band interference 
was being generated in my receive chain. However, with the gain 
that low, I couldn't receive anyone else. :-)

The K3 I was using has 250Hz 8 pole and 2.1KHz 8 pole filters in 
addition to the 2.7 and FM filters. I could get the interfering 
station out of the passband on the 250 filter quite easily, but 
there was still a wide band of noise covering the entire 2KHz 
band of the computer waterfall. Using the notch filter didn't 
eliminate the noise.

In the end we had 139 digital QSOs in the log and many more CW 
and SSB ones. We all ended up tired and happy which means we had 
a good field day.

Does anyone have any ideas about how to improve reception under 
these conditions?

Cheers - Bill, AE6JV

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