Is contesting with two rigs simultaneously something only for chestpounding bigguns or possible even without a fully automatted robot-station? During the last years I have tried a Single-Operator/Two Radio setup several times on the lowest possible level - with 5 W qrp and two multiband doublets. With this simple setup I got a feeling for the operating part of it without first having to invest in and deal with bandpass filters, interstation interference management and elaborate switching devices of all hard- and software kind.
What is it? SO2R allows to listen on one radio while the other one is transmitting. With my 5 Watts output I had no relevant interstation interference even when the two provisional antennas were quite close together. Each doublet had its own matchbox, fixed wired with one rig - no antenna switching device yet. Such a device will be more important if you do not
have equal (good) antennas. Then you should be able to swtich the better
antenna quickly from one radio to another (it is easier to hear a fresh
multiplier with the allband vertical than to work him with it because
the beam can´t be used easily).
IC-718 and K2 each with an own matchbox for the two doublets. Having no elaborate scheme for the CW input I use two paddles.
No workout for the soldering iron The only little building project necessary was a small box to switch the two audio streams in three different ways: Left audio for both ears, right audio for both ears (necessary when I want to concentrate completely on one signal) and third the REAL SO2R-position: right audio to right ear and left audio to left ear. What should be NEVER done - is simply soldering one audioline to the left channel pin of your headphones and the other rigs´s audioline to the right channel pin. Instant stereo receiving of two signals will destroy any fun with SO2R as well as efficiency.
Based on expert´s recommendation I added a variable resistor of 1k between the channels because our brain were better in channel separation with a bit of right channel´s audio in the left ear and vice versa - at least for me it works that way better than with full channel separation (try it and don´t argue with the grey software between the ears - do you argue with software in real life?)
Software Talking about software - most if not all contest software is able to deal with SO2R and
offer an overwhelming wealth of features - but also indicators for the
operator what rig is active and what key will now do what. To give you
an impression here a picture from the N1MM-manual. It takes some
reading, understanding and some little experiments to get the basic
feeling for it - but it is definitely not as hard as it may seem on the
first look. But to get it intuitive you will need "some" hours of
operating ;-) For more elaborate setups the software packages also offer switching of audio, antennas etc., too.
How to do? Now on with operating. The
most frequent use of SO2R is calling CQ with one radio and searching
with the second radio for unworked stations, especially multipliers on
the second radio on other bands (or checking condx on other bands or
finding a free slot for changing the running band). For this a very
widespread scheme is to switch audio by your software so that you will
have the second radio´s audio mono in both ears while your first rig is
transmitting (which should not need ear control). At the end of the CQ
the software switches the first radio´s audio in again on one ear to
let you listen for respondents and separates the second radio´s audio
to the other ear. Depending on the situation you then may even switch
to first radio´s audio completely in mono if copy is difficult. The difficult
moment comes when it´s time to call someone on the second radio without
interrupting running too much on the first radio (either because of brutal
stopping inmidst a transmission or having too long periods without
transmission on the first radio which will allow other stations to
occupy "your" frequency for calling CQ by themselves). The
more difficulty you have on the second radio to get the wanted CQing-station with the first
call and to pass the exchanges along without repeats the more difficult it
will be to keep up with the necessary running-sequence on the first radio.
One thing not so relevant for normal guys: Bigguns say that you can´t
do much SO2R with a rate higher than 100 QSOs per hour.
SO2R for normal stations More often we
will have to do search&pounce on two radios simultaneously which is
more difficult because you have lesser transmitting time in which you
have do deal with only one received signal (I turn my transmit audio down but don´t switch it off because it is needed when infos have to be sent by paddle). But you have less pressure
with interleaving qsos.
My favourite way to do it is using the
"waiting time" when I don´t get a CQ-ing station with the first call.
As soon as he responds to another caller I shift my attention to the
other ear that has the S&P-audio from another band (or I then switch this channel in). While I look for
other stations there, insert a call in the second log window and
prepare to launch the call I simultaneously follow the qso on the first radio
with "half" attention so that I can call in the right moment when the running station
launches the next CQ. For me it is more to shift attention between both channels than to completely copy both signals simultaneously (which is yet possible only in few precious moments).
In this way you can either increase your
rate by making one qso on one band and the next one on another band as
here (remember: it´s only qrp): 20071020 1646 20 CW LZ3FN 599 X06 599 173 20071020 1646 40 CW UA4SU 599 X06 599 76 20071020 1648 20 CW 4L1QX 599 X06 599 56 20071020 1649 40 CW YO5AJR 599 X06 599 28 20071020 1651 40 CW OF3OJ 599 X06 599 119
or by reducing the rate when you call a station on the second radio in
vain while at the same time the running station on the first radio
listens without a response (your transmitter is just busy with calling
on the second radio - transmitting on two radios simultaneously is an
absolute NO - even if technically possible in some setups).
You won´t transmit two signals at a time, will you?
To do or not to do - when? So it is crucial
to decide when it is time for SO2R and when not. You can go with your
gut feeling when the rate on one band is good - which is no time to do
intense SO2R other than checking condx on anempty band. Seemingly short
openings to valuable regions are another not too good time to S&P
elsewhere esprcially if you are qrp.This are also important moments for
inband-SO2R (if you´ve tested properly BEFOREHAND that it won´t do any
harm to your equipment - and then told your software to allow it)! If
you don´t trust your gut feeling (which might come to strange
conclusions say at 0400 morning local time) you better start to SO2R
when the rate on the primary band drops below a certain value - say 70
with LP and good antennas or 25 with qrp and modest antennas. But that
are rules of thumb to be exactly decided by every operator depending on
his targets and how much the contest has progressed (and possible rates
How long can you go? The sound of SO2R adds an element of turmoil to your ears and brain. Even
the best SO2R ops report increasing fatigue when doing intense
SO2R up to points when it is no longer possible. You have to get a
feeling when effiency drops too much because the internal QRM costs you
than it helps (a good sign is the error rate or missing letters when
copying a call with having the second signal in the other ear). To
reduce fatigue and improve efficiency it is very
helpful to switch audio intensively. Usually I listen "mono" to one
signal exclusively with both ears when I have to copy a real exchange
like a serial number - which is also more fair to the
running station not forcing him to send repeats. If fatigue increases
I turn the audio on one rig down to only hear whether there is a
station while S&Ping. A still helpful
and less stressing use of SO2R is to instantly scan i.e. 15/10m for
openings (you CAN rely on clusterspots from elsewhere but you are
better off with what is received at your station in realtime and before
the hordes stumble in).
Getting better A good way to have some training off air
is feeding MorseRunner (simulating a running rig) in one ear and
searching for stations on your real radio with the other ear. You can
make even a little contest for yourself: multiply the number of
MorseRunner qsos with the number of calls from the real radio (from
different frequencies, no pile-up-stripping!) for 15 minutes.
How does it sound in reality? Listen to K5ZD in WWDX with stereoheadphones and note i.e. how he switches audio.
you´re hooked - and there is significant risk if you have read until
this point you may be interested in the tech-stuff how to do it with LP
or even HP (not only for hearing something on one band while transmitting on another but to let your rigs live longer) and to learn more about what hardware and software can add
to automation. Look for fine descriptions by guys who are really into
it: SO2R-Overview from José Nunes, CT1BOH, regular WWDX-winner from CT3 SO2R-presentation by Stefan, DL1IAO, with precise schemes for qso-sequences and equipment A typical hardware setup by Chris, G3SJJ
Woooow!!!! You have read until this point. Thank you! That deserves a Refreshment´s refreshment. But be warned: Those are the most addictive 1:40 min I ever found on the net. So think well whether you really want to feel forced to hit the Again button every time you hear "Tack så mycket". Enjoy :-)))))