Thread: Trap dipole
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Old January 8th 07, 01:14 PM posted to rec.radio.amateur.antenna
Catweazel Catweazel is offline
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First recorded activity by RadioBanter: Aug 2006
Posts: 23
Default Trap dipole

Nate Bargmann wrote:

Thanks Bryan, I appreciate the practical construction advice. It is
always welcome.


FWIW I've made multi-band trapped dipoles in almost the same way;
however for the feeder I used light[weight] co-ax [RG58} terminated in
a 1:1 balun wound on a toriodal ferrite [IIRC, Phillips 4C6 material].

For tuning the traps, I jigged up an SO259 socket on some paxolin
board. The connection from the SO259 center conductor went via a 28v
light-bulb [voltage not critical I guess, but it's what I had] to a
flying lead terminated in a croc-clip., likewise the return to the
SO259 body via a flying lead and croc-clip. The coil/ co-ax capacitor
parallel tuned circuit is thus connected, in series with the
light-bulb, to my TX [IC735, on lowest power]. The resonant frequency
is indicated by ther light-bulb going dim or out altogether. Tweak coil
spacing/ trim co-ax capacitor to suit. Crude but effective.
HTH
73s de
G4GCJ