W8JI Writes:
> It's really ironic how we have abandoned conventional traps
> and loading coils and replaced them with systems that are
> significantly worse!!! I think this came about because
> manufacturers barraged everyone with commercials about how
> bad the other choice was. Then they gave us an alternative
> that was actually worse, with the only advantage being it
> wasn't what they convinced us was so bad.
>
> Some manufacturers have taken traps to a high level of loss
> by making them long self-resonant coils without capacitors,
> and even refuse to call the extra lossy traps they
> "invented" traps!
I think that part of the problem is that there is no longer
a commercial source of high quality traps. As far as I can
tell, the only relatively decent traps in recent memory were
by Reyco. Those have become more difficult to find (AES
www.aesham.com and RadioWare (www.radiobooks.com seem to
have them at times) and the quality seems to be somewhat
spotty.
With commercial coil stock even more difficult to find,
traps made of coaxial cable wound over Home Depot PVC
are an attempt by amateurs to make something work.
It is truly a shame that manufacturing and distribution
costs have made quality commercial traps a thing of the
past for the most part.
I would be interested in seeing how well homemade traps
using #10 THHN insulated wire on a 2.5" OD PVC (ca. 2"
pipe) and a doorknob capacitor would stack up. Even
then, with 5 KV doorknob caps running $16 each at RF
Parts (anyone know of a reliable source of ex-USSR
doorknobs?), the cost of a conventional home made trap
is about the same as Reyco traps from RadioWare or AES.
73,
... Joe, K4IK
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