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Re: Topband: In search of resonance

To: chetmoore <chetmoore@cox.net>, 'Tom W8JI' <w8ji@w8ji.com>, 'Tree' <tree@kkn.net>
Subject: Re: Topband: In search of resonance
From: Carl Braun <Carl.Braun@lairdtech.com>
Date: Fri, 31 Jan 2014 03:03:46 +0000
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Chet

Tom's right.  I get a clear dip at 8 MHz with X=0 and 5 MHz with X=0, both with 
good indications of varying reactance on both sides of the resonant freg.  I'll 
give his suggestion of 129' length a shot to see if I can get anything to 
resonate.  I have a pulley on the tower and one on the palm tree supporting the 
end of the L.

The closest AM broadcast station to me is 1450 am in Carlsbad which is approx 
15-20 miles away as the crow flies.

Tom

Maybe you saw my post where I stated that the MFJ plunged to a minimum reading 
of 4 0hms at 1825?  Does this reading mean that the L is near ground potential 
and 'in union' with the grounded Skyneedle at that freq?

If I can't get the antenna to resonate using the L I'd say that I'd consider 
shunt feeding the tower and work out an (omega) matching scheme to match the 
tower to my target freq.  If that's the case, do I mount my upper shunt arm on 
the tower at 67' or at 90'?  

Can I run a single drop wire into my panel and then switch the feed between two 
matching networks?  One for 160 and one for 80?

Please advise

Thanks

Carl AG6X


-----Original Message-----
From: chetmoore [mailto:chetmoore@cox.net] 
Sent: Thursday, January 30, 2014 6:22 PM
To: 'Tom W8JI'; 'Tree'
Cc: '160'; Carl Braun
Subject: RE: Topband: In search of resonance

Thanks for this tidbit of information.  As soon as this white manure melts
(some people call it snow)   I will do a re-check on my shunt fed tower.  I
think I did have at least one  dip to zero and never did find a resonance
point.

Thanks

Chet N4FX

-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Tom W8JI
Sent: Thursday, January 30, 2014 1:34 PM
To: Tree
Cc: 160; Carl Braun
Subject: Re: Topband: In search of resonance


> You might be dealing with AM BCB being detected by the meter - and 
> masking what you are looking for.
>

No, because he gets a dip to zero reactance.

If that happens anywhere, there is no BCI.


73 Tom 

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