[Heathkit] Heathkit Power Transformers

Glen Zook gzook at yahoo.com
Tue Jan 31 12:27:45 EST 2012


You were fairly lucky!  Heath did use transformers from various vendors as well as different "lots" from individual vendors.  I strongly suspect that different batches of transformers did last longer than other batches.  The failures were generally not due to wiring problems, failures of other components, etc.  Also, they generally were not due to higher line voltage.  The transformer in the DX-40 runs right on the ragged edge and any slight variation in the manufacture of the transformer, trying to get just a "little" more output, taking too long to tune, are just a few of the causes of the transformer failures.  Even running the VF-1 from the transmitter rather than a separate power supply was often enough additional load to cause a transformer failure.

The transformer in the DX-35 was outright overloaded!  When the transmitter was used for CW it was on the ragged edge and when used for phone it was definitely pushed over the edge.  My particular DX-35 still has its original transformer.  However, the very few times I do use it I definitely baby it and only use CW at about half the rated power.  Even then, I walk on egg shells and keep my fingers crossed that the transformer holds.
 
Glen, K9STH Website:  http://k9sth.com


________________________________
 From: Meir WF2U <wf2u at ws19ops.com>
To: heathkit at mailman.qth.net 
Sent: Monday, January 30, 2012 10:09 PM
Subject: Re: [Heathkit] Heathkit Power Transformers
 
Back in the early 60's I had a DX-40/VF-1 I bought used. I ran the
transmitter for a few hours almost daily, mostly on CW, and some AM. I never
had a problem with it; the transformer was barely warm to the touch. Finally
I sold it after 5 years, when I could afford a used transceiver. 
I wonder how many burnt-out transformers were caused by leaky or shorted
caps, rectifier tube internal short, or incorrect component values/wiring
errors. 


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