[CQ-Contest] The King (Packet cluster network) is dead! Long live the Kin...

RT Clay rt_clay at bellsouth.net
Wed Jul 28 11:30:15 PDT 2010

> (SO2R does of course force a different strategic decision:
> which other band will you do your S&Ping on?  Until
> someone works out the technology to S&P 
> on the same band on which they're CQing.  I'd bet
> someone is already doing that but hasn't yet released their
> secret!)  (I've done it in the ARRL DX 
> but only while running QRP)

Easy: current hardware has the capability to do in-band SO2R at any power level without the need for far-remote rx antennas, super filters, etc. All that is needed is a wide-band SDR hooked to the IF output of the transceiver. The trick is to use the recording/time-delaying capability of SDR:

When in RX mode, the system continuously records a slice of the band, keeping a certain amount of time slice (<30 seconds needed in practice) in memory.

While in TX mode, the computer plays the recorded slice back to the op in split headphone audio as if it was a second rig on another band. The op can then virtually tune through the samples, identify callsigns that are needed, and input them on a bandmap, all while transmitting at the same time. When ready to work a S&P qso, the computer just loads that freq into the 2nd rx vfo.

Not quite as efficient as cross-band SO2R because you can't really listen when you are transmitting, but I think it could come very close.

Someone just has to write the code. There are lots of other ways SDR can be used "unassisted" in logging programs as well.


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