Antenna woes

---------

From: DavidE70@aol.com
Date: Sat Jan 04 1997 - 10:31:07 EST


Hi gang -

After mucking with my antenna project with no success, I decided it was time
to plead for help from more knowledgeable souls, so here goes:

My setup is currently an OHR-100 on the 40m novice band, with RG-58 coax
running about 100 ft to an inductively-loaded shortened dipole running the
length of my attic (the dipole was designed based on the Weetenna article in
a recent CQ magazine, and my attic is reasonably metal-free but not entirely
so). I originally used a VanGorden 1:1 balun at the center of the dipole to
mate with the coax coming from the transmitter. When I first checked the SWR
of this setup it was about 5, so I tried changing the length of the antenna
by a foot or so on each leg, but the SWR remained the same. Next I tried
connecting a tuner. Any movement toward reducing the SWR using the tuner also
resulted in a reduction of power to the antenna.

Well, the first thing I suspected of causing my grief was the feed line or
its connectors, so I checked and redid the connectors on both ends. This had
no effect. Next, I carted my transciever up to the attic and connected it to
the antenna with a coax connector I bought at Radio Shack. Now, when I
transmitted, my normal sidetone was replaced by pseudo-white noise (something
I hadn't experienced before). Next, I tried replacing the balun with a simple
SO-239 connector (after taking my gear back to the shack) and reconnecting
the feed line, but the white noise was still present (interestingly, though,
the SWR reduced to about 3). If instead I connect a simple long-wire antenna
straight to the transceiver, the white noise goes away (but not my SWR
problem).

You've probably guessed by now that I'm thoroughly baffled and dismayed by
this whole mess. Am I overlooking something obvious? Should I abandon the
whole mess? My only alternative is a vertical like a GAP or similar, since I
don't have a suitable place for a full-size dipole or any other "simple"
antenna designs.

Any advice you could throw my way would be greatly appreciated.

Dave Ek
KB0YSN


Search QRP-L Archives

[ QRP-L Archive | ]
[ 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 ]

---------

This archive was generated by hypermail 2b29 on Fri Jun 02 2000 - 11:32:38 EDT

kd4ab@kd4ab.org