Topband: FairRite Products 2873000202 W2pm at
Sun Feb 5 11:55:58 EST 2006

In a message dated 2/5/2006 11:06:28 AM Eastern Standard Time,  
andy.ikin at writes:

My experience is based on the use  of these cores in receiving antenna 
applications ( low noise transformer  feedback amplifiers ), over the past 9 years I 
have wound thousands of  transformers using two hole type 43 material cores 
and to my knowledge no  failures have been attributed to either shorted turns 
or wires touching the  core. However, I have recently noticed that some 
Fair-rite cores ( made in Red  China ) have a rough surface compared to US 
manufacture, I have yet to  determine whether this may be problem!!!
Andy  Ikin  G8LUG

Thanks Andy - and all the others. I have made 5 of these based on Tom's  
designs shown on his site and ON4UN's new book and so far no issues with the non  
protected 1 turn primary. However, I semi-pot mine by putting a dab of epoxy 
on  each end of the transformer which not only keeps water out of the holes but 
 keeps the wires tight. And I like to pull the turns tight so that I can 
effect  maximum physical separation of the windings. Perhaps I'll find a larger 
teflon  sleeve for the holes and also continue to use the smaller teflon tubing 
within  that.

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