Sunday 26 July 2020

Things you learn working /P

Well, my endless question is: where do I go to spend an hour or two whilst my son goes skateboarding?

At least, when it's good weather for skateboarding, it's also good for radio!

IO73te, operating from dyke at extreme left.

So, off to IO73te, for some 10m work from a large bay.  Even the tide was in today!

My antenna is, as usual, an elevated 1/4 wave vertical, this time made with some wire I haven't tried before - heavy duty stuff (but not with any core reinforcement) from SOTABEAMS.

At just £11 for 50m, this is much more acceptable for non-permanent antennas than the £50+ cost for the same amount of kevlar-reinforced wire, for example.  It's actually good stuff, specially made to SOTABEAMS' specification, with a very strong PVC sheath and heavy stranded wire.  Also good tangle resistance - an almost universally-overlooked feature of antenna wire.

Having set up on a windy sea defence dyke, built in the early 19th century by legendary engineer, Thomas Telford, I suddenly found that my DC supply wire from the battery to the banana plugs of the rig had started to melt badly!

Meltdown!  Only use the best heavy duty DC supply wire, even at modest powers!

The wire is quite heavy duty stranded copper, but it is specified only for speaker wire duty.  As well as being slightly too thin for the rig, even at powers never above ~40W, the insulation is probably also not of adequate specification for heavy duty DC use.  Using only 10W for FT8, I split the twin wire to separate the conductors, in case it had melted through completely.  This saw me through the next 90 minutes' operating.

This is really something to look out for if you are wiring from your car battery and hiding the wires under plastic covers inside the vehicle.  There, you will never notice any melting until it's too late.

Anyway, I managed only one QSO on 10m, even though I was getting across to the US quite well.  When I ran a short burst of WSPR at 1W, as well as being one of only about three UK stations being heard by N2HQI, I was stronger than the others two by a median +11.5dB. 

A strong NW wind brings a taste of autumn to 28MHz WSPR listening at IO73tk.
UPDATE: Another visit to the north coast of Anglesey at IO73tk, yielded very good enhancements over my home delta loop, just ~2km inland, at 28MHz.  The median difference was +12dB, with a maximum of +18dB enhancement over the home delta, and a minimum of +7dB.





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