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
On 4/8/2011 3:46 PM, Steve Hunt wrote:
> Art,
>
> If you mean extending the ends off at 90 degrees to the main dipole at
> the 25ft/30ft level, that's fine. Just think of it as adding end
> capacity loading to an electrically short dipole. The important thing
> is that it raises the resistive component and drops the capacitive
> component of the feedpoint impedance - both of which significantly
> reduce the VSWR and loss on the open wire.
>
> But note that we are focussing on 160m here - there will be a "knock on"
> for the other bands which will likely be detrimental. On the higher
> frequency bands there will be much more current in those low
> extensions than there is on 160m, and that means the "effective
> height" of the antenna will be lower.
>
> 73,
> Steve G3TXQ
>
>
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