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Fw: Re: Re: Re: backfire helix question.



My attention to feed band width was created by the frequency
charactistics of the 1/4 WL stub.
A normal monofilar helical band width is wide .     How the 1/4 WL
matching section handles that wide band  width was what triggered my
query.
The reference to Tab matching occurred when you commented :
"I considered stub and such when I realized that with a relatively low
impedance , a single series-matching line transformer should be able to
do the trick"
I incorrectly assumed your stub and tab were simular.
I have been successfully using Tab matching for helical feed antennas.
If I had an address I could send pictures.    Your call.

Joe  K0VTY
=============================

On Tue, 18 Nov 2003 15:30:42 -0500 Scott Townley <nx7u@cox.net> writes:
> I don't understand what you mean by "tab matching".
> And I don't know that it's narrowband...I simply measured the RL 
> from 2375 to 2425 because that's what I set the sweeper to :-) I'll 
> sweep it wider this afternoon and report.
> > 
> > From: k0vty@juno.com
> > Date: 2003/11/18 Tue PM 01:32:52 EST
> > To: nx7u@arrl.net,  amsat-bb@AMSAT.Org
> > Subject: Re: [amsat-bb] Re: backfire helix question.
> > 
> > Would your original thought of Tab matching remove the narrow 
> banding ?
> > 
> > Joe  K0VTY
> > ===============================
> > On Tue, 18 Nov 2003 13:10:22 -0500 Scott Townley <nx7u@cox.net> 
> writes:
> > > It's broader than 50MHz...I swept it from 2375 to 2425 and it 
> was 
> > > <20dB RL the whole way...but I can open it up and report back.
> > > 
> > > > 
> > > > From: k0vty@juno.com
> > > > Date: 2003/11/18 Tue AM 11:39:43 EST
> > > > To: nx7u@arrl.net,  amsat-bb@AMSAT.Org
> > > > Subject: [amsat-bb] Re: backfire helix question.
> > > > 
> > > > Have you had a chance to look at the frequency band width of 
> > > > the backfire helical feed as you have configured the matching 
> ?
> > > > 
> > > > Joe  K0VTY
> > > > 
> > > > 
> ________________________________________________________________
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> > > 
> > > Scott Townley NX7U
> > > Gilbert, AZ  DM43di
> > > 
> > > 
> > > 
> > 
> > ________________________________________________________________
> > The best thing to hit the internet in years - Juno SpeedBand!
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> > Sent via amsat-bb@amsat.org. Opinions expressed are those of the 
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> 
> Scott Townley NX7U
> Gilbert, AZ  DM43di
> 
> 
> 

________________________________________________________________
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