[TowerTalk] Tuning a Force 12 C4SXL or EF240 2 EL 40 meter beam

Terry G. Glagowski TGlagowski at SBCglobal.net
Sun Nov 9 21:27:33 EST 2008


Has anyone had any experience TUNING a 2 element Force 12 linear loaded beam
such as the EF240 or C4SXL 40 meter section?

I have an MFJ antenna analyzer but all I can glean from the documentation is
that the reflector should be resonant about 100 KHz lower than the driven
element.

Does anyone have an actual step by step procedure for tuning this beam, also
some information regarding how height above ground will affect it from a near
ground position?

I have it mounted on a LM470D crank-up tilt-over tower and would like to set it
up for about 7100 KHz center.

Also, has anyone tried to switch between CW and PHONE using relays to lengthen /
shorten the linear loading, or simply add a stub to the driven and reflector
elements?

73, Terry / W1TR

 



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