I haven't looked up Hawker's comments yet, but another scheme is to wire
up a switch to disconnect the coil and extension wire for the higher
bands. I think I've seen a commercial product for that. Might require
making the basic antenna a folded dipole with bypassed relay coils being
the shorts at the ends so you insert series capacitors at the balun and
with a couple RF chokes apply DC to close the relays hanging at the ends
of the original center section.
73, Jerry, K0CQ
On 4/8/2011 9:56 PM, Art Trampler wrote:
> In the old vernacular--cool idea.
>
> Since the motivation was to get coverage on 80 and better coverage on other
> bands...the 160 was more of a, "What's going on here?" question. However, I
> like this thought on this one.
>
> Art
>
> -----Original Message-----
> From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
> On Behalf Of Dr. Gerald N. Johnson
> Sent: Friday, April 08, 2011 4:25 PM
> To: tentec@contesting.com
> Subject: Re: [TenTec] SLIGHTLY OT
>
> Perhaps it would be more useful to connect the ends through coils that would
> bring the antenna nearly to resonance on 160 and by their choke (neglecting
> distributed C to make into traps which may not be a perfect
> assumption) effect disconnecting the added wire on the higher bands. The
> choke will be more effective on 80 through 30 than 20 through 10 meters
> because the distributed will likely make the choke series resonant somewhere
> in that range and above that resonance it looks capacitive.
> I'm sure I've read about such chokes in Pat Hawker's antenna topics volume.
>
> 73, Jerry, K0CQ
>
>
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