SO2R…all the contesters are doing it.
I have wanted to try it for a number of years now. Finally, after several trials around the station engineering I used it to great success in the 2011 Wpx RTTY contest.
My setup: Icom IC-7600 as primary rig, Yaesu FT-857D as secondary. I.C.E 419B bandpass filters connected to each. All my antennas connected to the IC-7600, a 90-foot Inverted L connected to the 857D. Yankee Clipper Contest Club SO2R+ controller box between them, connected to my main station computer running N1MM and MMTTY for RTTY.
Aside from some slight harmonic QRM from each radio the setup worked beyond expectation. I estimate that I added better than 150 Qs on the second radio. I found it very convenient for using searching/pouncing using both radios. I am a little station and not likely to hold a frequency except on 40/80M evenings when I am strong stateside. Being able to scan two bands was very useful. There were times when I was running on 40M and was able to use the second radio looking for additional stations on another band.
RTTY operation was a great first introduction to SO2R. I have tried it subsequently with CW and found it to be very confusing. More practice is needed there (and likely trying different modes of headphone mixing). I played a little in the ARRL DX CW contest and found NO headphone mixing was OK. This is probably not optimum.
Things needed from this point forward:
- Coaxial stubs to pass/reject primary and harmonic frequencies. I could hear myself on my harmonics, sometime loudly and with blocking of the RX rig. Nothing damaging of the radio but annoying to say the least. I think I should be able to get another 40dB of rejection with coaxial stubs for various bands (and a way to switch them)
- Better antenna switching. I have a 6×2 switch but currently using just 1 section. Need to fix that! I want to use any antenna on any radio…
- Band choice automation. I need to be able to have my filtering track my band-choice. I don’t have dedicated antennas for each band so no tracking needed there. I picked up a KK1L dual-radio board for this very purpose. He has an Icom band-voltage module coming soon!
- Common-mode filtering. The more I read about common-mode interference rejection techniques (check the YCCC website) the more I am hearing hash/trash that is common-mode related. Need to start whittling away at this.