Two radios - when did it start?
First used in 1952 CW SS by W4KFC.
Several other people started using it in the late 1970’s
Period of transition during 1980’s.
Now required to win most domestic tests.
Early attempts with two radios
Transmit on two bands at the same time. Simply tie both rigs to your keyer.
Makes people wonder when you answer stations on the other band.
Discovered by several people in the 70’s.
Considered "unethical" for single operators and has been outlawed in most contests.
What do you do with it?
Listen anytime you are transmitting under computer control (CQing or sending exchange).
Scanning "dead" band for signals.
Finding multipliers.
Finding new QSOs (SS on Sunday).
Keeping an eye on the competition.
What do I need to do it?
Two Radios!!
Second radio can be low power - poor antenna (i.e. TS-520 and trap vertical).
No interference between radios.
Stereo headphones or automated switching to proper receiver.
No sidetones from computer sent CW.
Station layout
Both radios comfortable to use.
Put VFO knobs near keyboard.
Either rig used as "run" radio is nice.
Same type of radio is nice.
Audio
Radio Shack audio mixer.
Computer control.
Toggle Switch
Receiver volume control.
A natural for stereo cassette recording.
Antennas
Ideal is a typical multi-multi antenna system with no interference between bands.
Either rig on any band gives maximum flexibility.
Interference problems
Band pass filters can help.
Quarterwave traps are also useful for trouble spots (measure with antenna analyzer).
Check all antenna positions and combinations.
Consider separate receiving antennas as an option (i.e. beverage).
How much time do I have?
Sunday afternoon CW SS CQ is 8 seconds long.
Sunday afternoon CW SS Exchange is even longer.
CW Sprint exchange or CQ is about 5 seconds long.
When do I use this?
Whenever you can!
Most stations require two bands to be open at the same time.
Good results even during high rate hours (i.e. first hour of the CW SS). Lots of fresh meat, wait until no answer.
When you are looking to change bands.
Step by step process (CW SS)
You are running stations on 20 meters, listening for CQs on 15 meters.
You are answered by W7YAQ on 20 meters. You come back to him and send an exchange at 35 WPM.
You scan 15 meters for 5 seconds, and find N6RO sending an exchange.
N6RO found on 15 meters
You type in N6RO’s callsign and find it isn’t a dupe.
You send a QSL message to W7YAQ and are called by another station.
During the sending of this exchange, you determine for sure that N6RO owns the frequency.
N6RO calls CQ - so do you
You notice that N6RO and you are both calling CQ at the same time. Nobody calls you as you finish your CQ. You decide to call N6RO on the other radio.
N6RO comes back and sends you an exchange. You are sending a "dummy" CQ on 20 meters to occupy "your" freq.
A dummy CQ?
Yes - unless N6RO doesn’t come back to you, anyone who answers this CQ will wonder what is going on.
Experience has shown that the station calling will stick around for your next "real" CQ almost every time. Maximum delay is about 10 seconds. N5TJ has done this to me in almost every sprint!
N6RO is in the log
If you know someone else responded to your dummy CQ, often sending a ? will get them to repeat their call.
Otherwise, call a quick CQ to see if anyone is there.
This technique has been used during the SS CW in the first hour for 18 second radio QSOs during 110+ hours.
Finding a new frequency
You are tuning up 40 meters and are thinking it is time to QSY there.
You find a "clear" frequency.
You send a couple of quick CQs to see what happens. Send while listening for answers to your 20 meter CQs.
If nobody complains and you get a response - the frequency is "yours"!
Low power and QRP
Since your saturation from CQing is much less, you can find stations to pounce on much easier.
Allows you to CQ on the fringes, accepting a low response rate and still keep your total rate up.
These categories actually offer more benefit than the high power category.
Software
Efficient software can help simplify the two radio process and make it flow.
TR and NA both continue to improve two radio performance.
Steep learning curve - PRACTICE!!
DSP decoding of CW and further automation is still a dream - one which we might be better off to resist.
SSB Two Radios?
Being done by many people. N2IC is very impressive at it.
Best done when you have to send several CQs to get a QSO. Very hard to do when you have a pileup.
Beware of chopping up your "performance". Discourages non contesters from calling you.
Two Radios on same band?
Has been done at some multi-multis for years.
Possible to do with 600 feet of antenna separation at full power and solid state radios.
Much easier for low power stations.
Allows two radio techniques when only one band is available.
Two radios - puts the operator back into the equation.
Allows you to improve your score with your existing station.
Pays you for your hard work.
Makes Sunday’s more fun (you are always busy).
Gives you a better perspective of what is going on the other bands.
Three radios?
Alternating CQs on two bands, listening on a third band.
No software support (yet).
Limited applications - perhaps something like the All Asian contest.
Tried by a few people - mostly abandoned.
Comments on this web page to n6tr@contesting.com. Hope you enjoyed it.