An Introduction to SO2R Central Texas DX & Contest Club Robert Brandon, K5PI October 22, 2007

What’s SO2R? Single operator, two radio contesting Generally this means: –Two radios on two different bands –Headphone and paddle/microphone switching –One computer –Contesting software setup for SO2R –Fun!

What’s the basic idea? Generally, it means calling CQ on one radio, S&P on the other Keep busy, keep the rate up Cover more than one band at a time to catch openings, increase multipliers

SO2R is not... Listening to two signals at the same time Something only radio mutants can do Something that requires a lot of hardware Essential for a competitive entry Guaranteed to improve your score –Learning curve –Most improvement for LP, QRP

How could I get started? Get a second radio! –Whatcha got – IC-706? –Only one amp? So what! –Computer control for both is best Get a second antenna, even a modest one –Vertical, dipole, sloper –Separation is good, but less important for LP Get going! –Troll another band (10/15?) –Find a new run frequency –Grab the hand mike or keyer and work in a QSO

That was fun – what’s next? Get some switching –CW takes the least gear, maybe just a headphone switch –RTTY can be done with one TNC and a sound card –For SSB, you’ll want a voice keyer and microphone switch Learn the software – all support SO2R

Interleaving QSOs Automate CQs (e.g., DVK) and don’t listen to them (no monitor, sidetone) Find a station on second radio, dupe check and load “on deck” Get in sync with your target On unanswered CQ, pounce! After 2R QSO, return to CQ Working loud, snappy ops on 2R easier

SO2R “traps” Know your rate limit –If you’re getting an answer (or 2 or 3) to every CQ, does it make sense to work the 2R? –If you’re fumbling QSOs on your run frequency, it may be best to back off the 2R –May be best just to map 2nd band with placeholders, or listen for pileups (juicy mult, fresh meat) If conditions are marginal (e.g., low band QRN), it may be best to focus on 1R Since you’re always busy, it’s possible to lose sight of the best bands – watch rate Logging more 2R Qs? Change run band?

Some finer points Priority should usually be run radio –Especially if you have a good run frequency –Unless you find a really good mult –Casual ops may pass by if lots of aborted CQs Fills can be a hassle – SS tough for SO2R beginners. Have fill-on-2R messages programmed. Short, long CQs Advanced goal: 100% duty cycle on transmit –Launch CQ while receiving exchange –Dueling CQs Automated headphone switching? Maybe. Lots of SO2R aces don’t switch much. Try volume, pitch differential.

Moving mults Very effective technique (esp. NAQP) Best candidates –Someone you know –Casual op –Known SO2R op How to ask –Be assertive - “Can you work me on 21442?” –Ask running SO2R ops - “28?” Don’t move “blind” if at all possible Call short CQs on move frequency, dueling CQs

Typical station layout

Another station layout

Station layout considerations Simplify band changing with automation Design so either can easily be run rig Ergonomics – you’ll always have a hand on a rig –Radios on the table –Forearms on the table –SO2R switch very close at hand (foot switch?) Visual indicators important –Which is run radio (slide keyboard?) –Which rig is ready to transmit? (software) –Which rig is transmitting? (watt meters?) –What is being sent? (memorize!, watch speed)

References K8ND SO2R resource page: Techniques, pictures, equipment, etc. SO2R.htm SO2R.htm AA5AU