Towertalk
[Top] [All Lists]

[Towertalk] Force 12 XR-5 SWR problem (?)

To: <towertalk@contesting.com>
Subject: [Towertalk] Force 12 XR-5 SWR problem (?)
From: n0rq@swbell.net (Dave Dunbar, N0RQ)
Date: Thu, 19 Sep 2002 08:48:01 -0500
I have a Force 12 XR-5  (5 band, 10 element "multi-monobander") laying =
on the ground, almost ready to up right after the Trylon 64' goes up =
this Saturday.  However, I'm having an SWR issue that perhaps someone =
has some ideas on.

The SWR across all 5 bands except 15m is either good or quite =
acceptable.  But on 15m, it doesn't look so good.  I checked it while it =
was mounted it at 9' on a sturdy tetherball pole, as well as when it was =
pointing straight up in the sky (the 15m driver would have been about =
12' in the air).  I've checked it using several different types and =
lengths of coax, and I've tried an alternate balun (both Force 12).  =
I've tested with both a rig (FT-900) and an MFJ 259B antenna analyzer.  =
And of course I've double- and triple-checked the assembly, element =
lengths, etc.  It was done according to the Force 12 instructions, which =
were very good.

On 15m, the best SWR is near 21.6, with an SWR of about 1.5:1.  I can =
lower the "resonant" frequency to around 21.3 to 21.4 by lengthening the =
15m driver, but the best SWR I can then get is still almost 2.0.  Nicht =
gut. =20

Is there something I'm missing?  Is the thing simply too close to the =
earth to give me a reliable reading?  Do I put it up on the tower with =
the suggested 15m driver length, or should I stretch it a few inches and =
hope for the best?  (This is my first HF beam and first real tower, so =
I'm kinda nervous about it.)  Comments appreciated!

--=20
73, Dave, N0RQ
n0rq@swbell.net

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
---

<Prev in Thread] Current Thread [Next in Thread>
  • [Towertalk] Force 12 XR-5 SWR problem (?), Dave Dunbar, N0RQ <=