[Boatanchors] Lettine 240 Transmitter Plug In Coils

[David Knepper]

Drew, et al. the major problem that so many of us experience with these 
small plug in coils, in particular,  is that the support strips or ribs, 
over time, begin to disentegrate   Perhaps, it is due to the RF energy 
reacting with the polystyrene support material - I am no chemist.  The color 
of the materials actually turns from clear to slightly brownish.   From my 
experience, B&W coils are the worse for this problem.  Perhaps, someone much 
more technical can explain this better than I can.

David Knepper, W3CRA/W3ST
Editor of the Collins Journal
Secretary of the Collins Radio Association
www.collinsra.com
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----- Original Message ----- 
From: "Drew P." <drewrailleur807 at yahoo.com>
To: <boatanchors at mailman.qth.net>
Sent: Monday, December 13, 2010 2:50 AM
Subject: Re: [Boatanchors] Lettine 240 Transmitter Plug In Coils


> Richard wrote:
>
>    " I also wonder about the logic behind B&W's pricing. If
> the coils are uneconomical to make why not just discontinue
> them instead of pricing them out of reach. One would think
> that if low volume is the problem reducing the price and
> advertising a little would increase it quite a bit. Or,
> perhaps, they could just farm them out. I suspect that
> whatever patents B&W has will have long ago expired and
> would tell you how to make similar coils. Essentially, the
> are just air-wound coils on strips of polystyrene for
> support."
>
> B&W is still selling coils at this price; otherwise they would have
> discontinued them. How many coils? We don't know, but this type of
> inductor is very much out of fashion in most new equipment construction.
> Look inside a reasonably contemporary HF radio; you won't find
> Air-Dux/Miniductor type coils.  Hence, small demand for these nowadays.
>
> Drew
>
>
>
>
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