Tuesday, 12 August 2014

SOTA Activation Ditchling Beacon G/SE-006

On Saturday 26 July I activated SOTA summit Ditchling Beacon (G/SE-006). Although there is a bus from Brighton to Ditchling, I enjoy walking so I took an early train to Lewis followed by a 10km walk along the South Downs Way.  My plans went slightly awry when the Southern train broke down at Haywards Heath, but after a 30-minute delay we arrived at Lewis.  This section of the South Downs Way is well signposted and so I did not get lost this time. My pack was a little heavier than usual. It was a very hot day so I carried extra water, not knowing that there would be an Ice Cream van, also selling water (but two quid a small bottle!), at the Ditchling car park. The walk took around 2 ½ hours, including a short sandwich stop.
M0BGR/P at Ditchling Beacon, G/SE-006. July 2014

I have never suffered a catastrophic failure on one of these expeditions but today was the exception. I use a small plug box (in the foreground of the photo) so I can quickly connect several items to my  lead-acid 7.2Ah battery. I wired up the FT-817 and switched it on while I set up the Super Stick HF antenna. After about 5 minutes there was a bang from the vicinity of the plug box and the 817 reverted to internal batteries. I quickly disconnected the lead-acid battery and began to investigate, thinking something had shorted. All the external wiring seemed OK so the problem had to be in the plug box.
I carry a small tool kit but I had omitted to include a small Posidrive screwdriver, required to open the plug box, and a multi-meter which would have been helpful when fault finding. I could have carried on by either using the FT-817 internal batteries, which would have lasted about an hour, or directly connecting the 817 to the battery – a little inconvenient as I could only power one item at a time. I decided to investigate and was able to open the plug box, carefully, with the tip of my pen knife blade.  The inside was a complete mess! It used to have an electrolytic capacitor but this had blown itself apart. As this was not required for battery operation I surgically removed it, cleaned out the wreckage, put the box back together again and re-connected everything (carefully!).
The 817 was still not receiving power but checking fuses without a multi-meter is difficult and none had obviously blown. I am a bit fanatical about fusing everything and there were three fuses in the 817 circuit. Fortunately I carry spares, taped to their respective leads so I opted to replace them all even though only one should have blown. I had been some time since this plug box had been used. I powered it up before leaving home, but only for a few seconds, so I guess this was not enough to reveal a weak electrolytic capacitor even though this was adequately rated for the job (100 uF, 25V).
 Next timecheck tool kit, test everything properly, before leaving home, and carry a multi-meter!
Finally, I was on the air and firing on all cylinders. This was the day of the IOTA contest so I spent most of my time on the WARC bands, with occasional calls on 2m and 4m FM. This was the first real outing for my new Wouxun KG-UV6D – it performed well.  Band conditions were not great but I quickly worked the four stations I needed for a valid activation, thanks to Mike, G6TUH, who I worked on several bands and also spotted me on the clusters. I was on the air for three hours and worked 14 stations, including 5B4KH in Cyprus (Asia-004 in the IOTA contest). During the afternoon lots of people stopped to ask what I was doing. Although this interrupts operating time, I always take the opportunity to explain amateur radio and why it is relevant today.
I packed up in time to catch the last bus to Brighton, but it was such a lovely afternoon I decided to walk back to Lewis, after pausing for an Ice Cream! The walk back was uneventful, apart from getting a painful blister on my right foot with about a mile to go which I had to stop and sort out (I always carry a basic First Aid kit). On the walk back I was passed by lots of Ghurkha soldiers who were doing a 100km run along the South Downs Way that very hot day, which rather puts my 10km walk into perspective, but they weren’t carrying an amateur radio station!  

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