stevel at hpsrfh.sr.hp.com
Fri Sep 10 14:52:02 EDT 1993
>What company has the ferrite balun kits that you slip the beads over the coax?
>Any luck with them? Recommendations? TNX Ralph Bellas, K9ZO
RadioKit, although I don't recommend using the kit they offer using the
Chosorb (?) beads. The beads they offer for use on RG8 type coax do not
produce a high enough impedance to do a good job of choking any currents
flowing on the outside of the shield. They work okay on 15/10m, but only
marginally on 20m and not at all on 40m and lower. I made a number of
measurements on these beads and they don't seem to work in this application.
The original article on bead baluns was in March 1983 QST. It used 50
#73 beads slipped over a teflon (RG142) cable. I've been using this
method and it has worked wonders on my Mosley antennas (TA-53M). I'm using
48 beads as they are sold by the dozen. I believe that Amidon sells the
coax and, of course, the beads. Don't substitute for the teflon cable--
the beads slip over it nicely and it can handle several KW at HF--something
that RG58 can't.
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