Mike,
The 50 ohm side was made up of Litz wire from the Decca tank coil. The loop side was #4 stranded wire with pvc insulation.
After examining the transformer close up it appears that the transformer arced from primary to secondary. This seems to be correlated with the damp rainy weather yesterday, the transmitter was running full power for 6 and a half hours before the transformer arced over.
--
73 Warren K2ORS/WD2XGJ
FN42hi
http://www.w4dex.com/wd2xgj.htm
-------------- Original message ----------------------
From: "MIKE REID" <[email protected]>
What type of insulation & wire gauge did you have before?
Mike
WE0H
WD2XGI
----- Original Message -----
From: Warren K2ORS/WD2XGJ
To: [email protected]<mailto:[email protected]>
Cc: LWCA LF Reflector<mailto:[email protected]>
Sent: Tuesday, January 31, 2006 5:18 PM
Subject: Re: LF: XGJ
Hello the list,
I disassembled the toroidal transformer in the loop ATU and found the
cores to be good. I will attempt to pick up some teflon insulated wire tomorrow
and rebuild the transformer, if all goes well will be back on the air tomorrow
evening.
--
73 Warren K2ORS/WD2XGJ
FN42hi
http://www.w4dex.com/wd2xgj.htm<http://www.w4dex.com/wd2xgj.htm>
-------------- Original message ----------------------
From: (Warren K2ORS/WD2XGJ)
> 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<http://www.w4dex.com/wd2xgj.htm>
>
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