[Towertalk] Force 12 XR-5 SWR problem (?)
Dave Dunbar, N0RQ
n0rq@swbell.net
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
---