Trimmed Van Gorden All Bander - suprise!
 

I'm just getting setteled into a new QTH and funds
are tight so instead of buying a tuner to tune my Van
Gorden "All Bander", I decided to see if I could
trim it to resonance on 40m.

For those who don't know, the All Bander is a
ladder line fed 134' dipole. It comes with 100'
of ladder line but I didn't need nearly that much so
I trimmed the ladder line to 50'. At that point I
have a 12 turn, 5-1/4" dia coax choke then 20'
of RG58 going to my SWR meter.

As a 134' dipole, the antenna presented a good
swr at 5, 20 & 28 mhz. I wanted 40m so I started
trimming. By the time I was done I had shortened
the antenna by about 25 feet per side. I'm not sure
exactly how much (+/- 1 ft) I trimmed but I was
VERY carefull to keep the antenna even sided.

The antenna now presents a good SWR centered
at 7.151 mhz but it also is OK at 18-19.5 and
26.5-28.5! Sweet! Performance seems good, too
(or maybe condx are good now)...

The antenna is setup as a dipole with apex & ends
at about 17' AGL. It runs facing 290 & 110 degrees.
One end ends up in a tree, the apex up on my roof
and the other end via nylon twine to a telephone pole.

What I don't get is if I shortened it, why did the 20
mhz low swr point move *down* 1 mhz while the
5 mhz point went up to 7.151 and the 28 mhz point
went down 1/2 mhz?

I'm happy with the results as I now (with a seperate
dipole for 20m) have my 4 favorite bands: 40, 20,
17 & 10.

Anyone care to offer a theory as to what's going on
with this setup?

73's de Ken KG0WX

"Ken Bessler" wrote in message
...

Anyone care to offer a theory as to what's going on
with this setup?


you plugged it in and it worked... what else need be said. all the
speculation in the world may not get it exactly right, but hang on, there
will be some in here who will try anyway.