Until recently the 4O3A location was mostly used in contests to compete in the SOAB category. Whilst visiting Tallinn in early 2014, we struck a deal to put together a serious M/S entry for 2014’s CQWW SSB & CW Contests.

With WRTC2014 behind us, preparation began in the summer. These days, from a technical standpoint, the Multi Single category is very complex.

Given our geographic disadvantage (when compared to our competition in the form of TM6M and EI7M in “the West”) our technical know-how was all the more important and had to be exploited to the full in an attempt to compensate for our “2000km handicap”.

Despite the arrival of a new category here at 4O3A, I wanted to organize my station in a way that preserved its flexibility, allowing it to be easily reconfigured for SOAB for example. Such flexibility was achieved with just a few additional switches.

The final setup is shown below:

Diagram 1 shows all 6 transceivers used for M/S. Diagram 2 shows the connections between the high-power filters and relay switches. To simplify this setup, I had to develop and build several new products:

• Station Genius
• RS3000 Revirsible Switch
• PS3000 RX AUX Splitter
• A/B switch
• 1A2R amplifier router

Station Genius is an easily programmable controller, and controls the switching of all antennas, filters etc. It was implemented with a smart interlock function that has priority levels control, station overview using TCP network and features sub groups. The sometimes complicated interlock functionality is now very simple for any contest station configuration, regardless of the number of radios present.

You can read more about Station Genius here.

RS3000-Dugme-story
The Reversible switch has 80dB of isolation at 30MHz and enables easy swapping of antennas between two radios. If one of the In-Band radios has “serious antennas”, yet the other a small tri-bander and wires, you can use the Reversible switch to simply swap antennas with a single button. Similarly, an In-Band radio can swap antennas with the RUN radio should there be a need. These features bring great flexibility in a simple way to the station setup, avoiding the dangers of hot switching etc.

You can read more about the Reversible switch here.

PSRX3000-Dugme-story
The Reversible switch has 80dB of isolation at 30MHz and enables easy swapping of antennas between two radios. If one of the In-Band radios has “serious antennas”, yet the other a small tri-bander and wires, you can use the Reversible switch to simply swap antennas with a single button. Similarly, an In-Band radio can swap antennas with the RUN radio should there be a need. These features bring great flexibility in a simple way to the station setup, avoiding the dangers of hot switching etc.

You can read more about the Reversible switch here.

AB-switch-Dugme
The High Isolation AB Switch, as its names suggests, has great isolation and thus enables the easy routing of antennas. As shown in Diagram 2, antennas from Tower 3 are always connected to MPL3, except when in use at the RUN or MULT2 radio. Activation of the switch is achieved using signals from the Band Decoder of the RUN and MPL1 radio.

You can read more about the AB Switch here.

Example

With the RUN radio on 20M, it takes the antenna for 20M, all remaining antennas are available to the MPL2 radio which cannot select antennas for a band in use at the RUN or MPL1 radios. The MPL2 radio can’t be on the same band as the RUN or MPL1 radios anyway, and thus has lower priority. Should the MPL2 radio arrive on the same band, isolation is key with these switches keeping all the receivers protected. You can read more about the High Isolation AB Switch here.

Run band organization

The RUN band has three radios and four active operators.

RUN1 and RUN2, listening in different directions (or angles) using the RX AUX Splitter, and In-Band1 and In-Band2, swapping antennas using the Reversible Switch.

These three radios are interlocked using SSC XL controllers, which also control and switch antennas. They are addressed as SubGroup 1 and are all interlocked.

Multiplier radio organization

Exploited by three operators using three radios.

MPL1 and MPL2 have access to the “main” antennas and listen on the same band. Should the RUN radio be on the high bands, MPL2 can use In-Band 1 antennas thus allowing its receiver to remain active while MPL1 transmits. MPL1 and MPL2 are of course interlocked.

The MPL3 radio has access to antennas from Tower3 and is used to check for the new RUN or MULT band. It is interlocked using SSC XL.

MPL1, MPL2 and MPL3 stations are addressed as Subgroup 2 on SSCXL controllers, and are of course interlocked.
Due to the flexibility offered most antennas are tri-bander stacks. Mono-banders are still use on one tower but will soon be replaced by tri-banders.

Some of the advantages of using tri-bander stacks (when compared to mono-banders):

• Less real-estate required
• Less towers required
• Less hardline
• Larger azimuth angle covered (less rotation required)
• Mechanically simpler
• Lighter and smaller footprint overall, thus preserving tower structures
• Easier to maintain

Naturally the above assumes a Triplexer system (with high isolation) such as 80dB is used.

At CQWW SSB, to further compensate for our “2000km handicap” we invited a number of great operators (many of whom featured at WRTC2014). The optimized technical platform described above, exploited by some of the World’s finest operators, allowed Team 4O3A to overcome its initial apparent disadvantage!

The fantastic live scoreboard at www.cqcontest.ru added to the excitement.

The final setup is shown below:

With TM6M retiring to the M2 category, we were focused on EI7M’s efforts. Saturday evening saw EI7M some 700K points in front of us as they piled on North American 3 pointers, unreadable at 4O3A. We pushed on through the night and our dedication paid off. In the early hours of Sunday morning we’d taken the No.1 spot. With another evening ahead of us however (where the Irish would benefit from 3 more hours of 3-point fun) we knew we needed to build a very healthy margin to preserve a 1st place finish. Conditions prevailed and by Sunday evening, as the high-bands closed on us, we were a decent 1.6M points ahead. By 21h00 GMT the margin had slipped to just 1.1M but it was too little too late for EI7M. 4O3A claimed 1st place Europe with almost 10,000 QSOs in the log and the highest number of multipliers in EU in our category.