Akademisk Radioklubb


SAC SSB 2018, and stupid things to do at the start of a contest

Following up on the hype from our small entry into CQ WW RTTY two weeks ago, we wanted to get our feet wet with some serious contesting. Saturday 12z we were ready to do an honest attempt at the SSB portion of the Scandinavian Activity Contest (SAC). The SAC contests are great for Scandinavian operators, this is our time to shine – lean back, call CQ, and enjoy the pileup.

In our eagerness to get on the air, we managed to do at least two stupid things. The first was to dismiss the impending signs of disk failure on our dedicated run computer, which later came back to bite us in the ass. The second was to hoist the mast.

One very unhappy coax.

Upon hoisting the mast, one of our cables got stuck in a square piece that protrudes from the mast. The cable proceeded to strip most of its outer cape, and get a nasty bend. When we started tuning trying to get multipliers on our rotary 40/30 m dipole, we were shocked to notice a 5:1 in SWR. Whelp!

Since 15 m was mostly closed, we were left with only 20 m to work for a while. The conditions were fine, so that trotted along nicely for couple of hours – netting us 120 QSOs, counting 5-10 Search-and-pounce (S&P) QSOs on the Mult station working 15 m.

Suddenly we got a message that we were being heard on an In-Ear-Monitor (IEM) in Klubben – and sadly had to stop working to allow the artist to finish the sound check. These are the woes of working amateur radio contests from a concert hall. This is actually the first time we have had interference problems on 20 m in recent years, so that was interesting in its own way. Somewhat dismayed, we packed up our things and decided to return the next day – deciding that our competitive edge was too blunt this time.

Jens, LB6RH, focusing on the pileup.

Back for day two we were able to get on 40 m with a spare dipole – netting us a total of two S&P QSOs :D. Our main workhorse was 20 m, but when we attempted to set up N1MM+ for automatic voice keying we had our second meeting with disaster, this time from a particularly unhappy disk drive. Both SmartSDR CAT, and N1MM+ wiped all their settings after a write operation to the disk, and then proceeded to crash the OS, uh-oh… A quick migration over to Shack-02, and we were working again, although a little annoyed.

We ended up working the rest of the contest on 20 m, and got rates between 50 and 60 QSOs per hour, which was quite fun. Conditions deteriorated towards the final two hours, and our skips towards England in particular was giving us a lot of trouble. Weak propagation with lots of fade made it hard to decipher the needed info, so on some instances we spent many passes to get the QSO completed. We also heard a lot of stations calling that we simply were not able to decode, hopefully we will be able to work those in the next contest!

In the end we got 235 QSOs, and 47 multipliers – not an impressive score by far. Considering we only got to work 5 hours, and the problems encountered, we are satisfied.

The following Monday it was time to set out and figure out what had gone wrong with the 40 m setup.

Left arrow: Service loop stuck on wrong side of dipole attachment point. Right arrow: Bracket that stripped/destroyed coax.

On our HF-mast we have a service loop that allows the coaxial cable, and rotor control cable to extend nicely along with the mast. During a repair/inspection of our 160 m dipole we apparently managed to attach the dipole end point in a way that traps the cable-bundle in an unhealthy position. This in turn led to the damage seen below.

Damaged coaxial cable.

We cut away the damaged section, and spliced the feed with a fresh pair of connectors. There was also some stripped cable further up the mast, but this was only superficial. This will be fixed later with the trusty combo of self-amalgamating and super 88 tape. After measuring the newly crimped cable with our antenna analyzer it turns of that the previously damaged cable actually belongs to the 15/17 m elements of our Force12 5BA HF-yagi. This was very surprising, as we had worked a number of contacts on the broken 15 m cable.

Since it was apparent that this had not fixed the issue, more troubleshooting was needed to identify the culprit behind our 40 m outage. Returning to the band selector to do some further measurements, a nasty looking connector was discovered. During serious contesting we use a 4O3A bandpass filter on the 40/30 m antenna, in order to reduce harmonic impact on our 20 m run station. It turns out that while mounting this filter during contest prep, the connector was strained too much, causing the braid to come loose. After terminating a new connector, the antenna played nicely again.

40/30 m antenna response after attaching new connector.

After getting some distance to the troubles we had, it was actually a fun contest to work, and also satisfying to be able to mend what we had broken. Before the next bout we need to get a replacement computer, and then we should hopefully be set for a “snag-less” contest :).


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