Thread: Trap antenna
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Old October 20th 11, 11:28 PM posted to rec.radio.amateur.antenna
Sal[_3_] Sal[_3_] is offline
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First recorded activity by RadioBanter: Jul 2011
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Default Trap antenna


"béo-master" wrote in message
. fr...
HI,

I picked up two coils that could be a trap for the CWA-840 COMET antenna.
(They have two stickers "CL-840").
The manual of the CWA-840 says : 40/80m dipole.

I found amazing that there isn't any capacitor in // of these coils...
These coils measure 76uH.
Could someone tell me how they works ?
In the manual of the CWA-840, each leg of the 7MHz section, is
11.1meters in lenght , wich, it seems to me, that it is rather longer
that 1/4 wave. (10.1m).
Why ?

Thanks a lot for your answers

CWA-840:

-----[ ]-------------ooo--//--
2.3m coil 11.1m balun


All coils are self-resonant at some frequency. Wind it right and off you
go!

"Sal"