I would change the length of the feed line by 20 or so feet. Either add or
take away. I do hope the feed line is reasonably straight an if there is
any excess is not in a "coil" somewhere.
Also, are you using a 4:1 balun or a 1:1 balun? And are these voltage
baluns or current baluns? I find that 1:1 current baluns work better in
most cases unless one is feeding something like a folded dipole where the
impedance is close to 200 to 300 ohms. In this case a 4:1 works better.
Based on what you describe, I suspect that you are using a 4:1 balun. That
device doing it's job and presuming the load Z at the feed line at the
transmitter end is say 25 ohms then the 4:1 balun is making that look like
6.25 ohms. Most tuners have a problem with this. Therefore a 1:1 balun
would present a 25 ohm load to the tuner. Much better.
73
Bob, K4TAX
----- Original Message -----
From: "Phil Sussman" <psussman@pactor.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Wednesday, January 21, 2009 7:15 PM
Subject: [TenTec] Antenna question
> This may be a bit off-topic - If so please forgive me:
>
>
>
> I'm working with a fellow who has problems loading an 80M loop antenna
> with
> ladder line and a tuner. His antenna is about 380ft and I think that it's
> a bit
> short. I borrowed my Nye-Viking and the best that I can achieve is 3 to 1
> match
> at 3800 KHz.
>
> At that point the tuner is applying MINIMUM capacitance. That makes me
> think
> that a longer antenna length is needed.
>
> As an aside 40m loads no better 2.5 to 1, but 30m loads up OK.
>
> If I take his balanced line and feed it as a long wire (one end
> unterminated)
> the system loads up just fine on 40m and 80m, but it is obviously
> unbalanced.
>
> Any quick hints appreciated -- I'm not the best with HF antennas.
>
> PS. My 80m loop antenna is 420ft long and loads as balanced just fine.
>
> de Phil - N8PS
>
>
>
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>
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