Crystal Set Build Entries

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Last Friday 3rd November we held a Club challenge.  This was instigated by Lin M0TCF after a discussion about Crystal Sets one night in the Club.  As the conversation progressed, He came up with the concept of a “Club Challenge” open to all to build one that could receive the Club net frequency of 3.663Mhz and any other bands the builder felt they wished to include.

We made all the information available on the club website and made regular announcements regarding the challenge at Club nights too and we did manage to get a few entries.  Admittedly not as many as we may have hoped as from the conversations going on in the club, it appeared that more were going pitch in and have a go.  It was also interesting to see that from a few junk boxes that were brought in as give away items, all the Air Spaced Capacitors disappeared really quickly.  

Nonetheless we had a number of entries of very different types and designs, from quite simple to quite complex.

So, come the Friday of the challenge, we set up an antenna of some 60 feet stretched across the car park and an earth was obtained from the nearest socket outlet.

Each entrant gave a short talk on their build and anything unique about it.  After that, the testing and judging commenced.

Testing was done by Andrew Lenton G8UUG and a small team of volunteers who were happy to take part in the judging as they were not building.  The sets were all  connected to the same antenna and earth and a small LM386 based Audio Amplifier was used to allow all the judges to hear the radios for themselves as well as any club members who wished to take a look as they were being assessed.

The sets were evaluated on a number of criteria including reception and specifically the ability to receive the Club Frequency, selectivity, audio quality, use of recycled/repurposed materials, build quality and innovation.

The test signal was kindly provided by John 2E0SPS who sat and operated the club rig with the output turned right down and sending “CQ TARS Crystal Sets” on 3.663Mhz AM when called to do so. 

Well, did they all receive and who won?  That fellow members is something you and I will have to wait to find out at the Presentation Night in the New Year as the results will be announced then.   

Overall it was a great fun challenge and I think most who took part learned something from it too.  I know I did!

It is hoped that we may be able to create more challenges of this type and that we may get a few more entries if only for the fun of doing so.

Please all think about the Club Construction Night too which is also coming up in the New Year.  Last year we postponed it after there was a very poor number of items submitted on the original date. We then moved it back a few weeks to allow a few more to build something.  There is now plenty of time to get those Soldering Irons heated up and start building something for the Construction Cups.  Please take part and support your club events that we take a lot of care in organising.

Best 73s all

Jeff M0WSZ

TARS Chairman