Hello the list,
Many thanks for all the reports last night from Hartmut, Jean-Pierre (F5YG),
Juan, Gary, and Roelof (Hope I didn't miss anyone!)
As many of you have noted the signal dropped off at 03:00 UTC. At 04:00 I
noticed XGJ was very weak on the W3EEE 'grabber'. I went downstairs to the
radio shack to investigate. The antenna current (measured at 50 ohms) was less
than 100 mA ! It should be approximately 5 Amps from the Decca PA. I checked
the Decca on a dummy load and it was ok. I tried the smaller transmitter and
noticed a very high SWR. I went out and looked at the ATU, flashlight in hand.
The secondary of the toroidal step down transformer had arced and burned
through the insulation. I believe that the very high humidity played a part in
the breakdown of the insulation. I will have a look at the transformer today
and may be able to repair it if the toroidal core is not damaged. I am hopeful
that the core is o.k. since impedance measurements showed no change and I was
able to run the 250 watt transmitter into the antenna with a low swr after a
period of time (after the tuner cooled down).
I will of course use better insulated wire for the high voltage!
--
73 Warren K2ORS/WD2XGJ
FN42hi
http://www.w4dex.com/wd2xgj.htm
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