Wednesday 7 August 2013

Discone Diva

The discone is now mounted in its final location in the loft. Currently fed via a run of RG-58 with several splices and adapters, but still pulling in VHF and UHF air transmissions. The feedline isnt ideal, calculated loss is about 2.8dB at 300MHz. So, Sam and I spent a little time yesterday running a nice tidy new length of Times Fibre TFC-10 CATV coax. Although this is 75ohm, its loss at 300MHz is a mere 0.85dB, a considerable improvement, and anyway, a sweep of the discone with the antenna analyzer revealed its resonant much closer to 75 than 50 ohm. The cable still needs connectors installing, but it should be a great improvement.

The FT-857D looks like it might be a much harder job than I can manage. The parts that would need changing are tiny, well beyond my soldering kit, so its all down to whether my previous boss will allow me to make use of his workshops SMT stations. As a result of this job, ive not even started the show antennas. I have a feeling were going to be limited on the bands this year! Still, being indoors means we should get more operating time, and having mobile internet now means I can establish out frequency on the 'net.

Also, to compound matters, the main PC failed yesterday. Getting this back online, or replaced and its data recovered, is much more a priority than anything else im afraid.

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