If you've got a good match at the antenna, changing coax length shouldn't
make much difference other than longer will be a little lossier even on 40
therefore it might look a very little bit better. If your match is not good
at the antenna you might find a good spot by varying the coax length but it
could screw up any other band that also had a not so good SWR at the
antenna. I use that idea to flatten the SWR on my LP - a box with relays and
2,4, and 8 foot lengths of coax giving me 2 to 14 feet in two foot
increments - good for 6 - 20 meters. The same idea could also be used to
fine tune the takeoff angle on a stack if the individual antennas are well
matched to start out with. The length changing can be done any place along
the line that's convenient - either end or anywhere in between.
Gene / W2LU
----- Original Message -----
From: "Mike Murphy" <kd8ok@yahoo.com>
To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Sent: Wednesday, January 20, 2010 8:07 PM
Subject: Re: [TowerTalk] Hustler 5BTV Problem
> Just a guess, but your 60 feet of coax is suspect here. Try adding 5 or
> 10 feet of coax and I bet your problems go away.
>
> Good Luck!
>
> __________________________
>
>
> Michael Murphy - KD8OK
>
>
> kd8ok@yahoo.com
> __________________________
>
>
>
>
> ________________________________
> From: Kelley <kshaddrick@jetup.net>
> To: towertalk@contesting.com
> Sent: Wed, January 20, 2010 6:47:32 PM
> Subject: [TowerTalk] Hustler 5BTV Problem
>
> I've been working with a 5BTV antenna for about two weeks now. I've got
> good SWR readings on 10m, 15m and 80m. Higher but usable readings on
> 20m. However, I can't get anything under 2.0:1 on 40m. The antenna is
> ground mounted with 20 25' radials. It's fed with about 60' of coax.
>
> I've tried the normal tuning as well as adjusting the traps. Nothing
> seems to bring the SWR on 40m down to something usable.
>
> Anyone have any ideas I can try?
>
> Kelley - W0RK
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