[Antennas] (resend) Can't tune Cushcraft Ringo

Sun Mar 4 21:47:26 EST 2007

Hi All,
This didn't come through, so I'm resending it.
I've just completed a full overhaul of the "inherited" "Ringo" style CB
antenna that I was planning on using for 10M beacon service. That included
cleaning it, replacing all rusted hardware (most of which had to be cut off)
with stainless steel clamps and bolts etc. This antenna appears to be a
Ringo AR-10 except that it DOES NOT have a separate coax matching stub, or
place to put one.
This thing was in very poor condition, it was obvious that the previous
owner (SK CBer) had trouble tuning it as it had "clamp" or screw marks all
around the matching ring. One end of the ring was stress-broken where it
bolted to a bracket. I flattened it and re-attached it properly. Probably
shortened the ring by about 1/2 inch. I can't imagine that would affect it
much since it 'is' adjustable. Sometime in the past the original "shorting
wire" or bar was replaced by a piece of half inch angle aluminum and clamp.
This MAY be my problem since it would likely have a different inductance
than a wire the same length.
The specifics:
1. Adjusted starting length to 200 inches per the AR-10 manual.
2. Put the ring tap at approximately the correct position per the manual.
3. Preliminary test about 6 feet above the roof on a ground mounted
"push-up" pole that could be easily walked up and taken down for adjustment.
Test results.
1. Resonant at 24.4MHz, 1.5 SWR.
2. Shortened antenna by 12 inches, almost NO change in resonant frequency.
3. Shorted it by 2 more feet. Resonance changed to 24.8 MHz, 1.5 SWR.
4. At this point I adjusted the "ring" and was able to get 1/1 SWR, but NO
change in resonant frequency.
In frustration I went back to the 200 Inch starting length, resonance
changed back to about 24.4MHz. I 'suspect' that the 24MHz resonance is
being presented by the "ring" and NOT by the actual antenna element itself!
At that point I pulled it down from the test position and put it away for
"another day".
For the life of me I CANNOT figure out why it won't work as designed, unless
the insulator that holds the upper section in place inside the lower (ground
or mast section) is shorted out. I haven't removed the ring to see if it is
or not (the antenna is normally a DC short). If it IS shorted through the
insulator the antenna is scrap as far as I'm concerned.
73 de Phil, KO6BB
DX begins at the noise floor!
THE BEACONEER'S LAIR: http://www.geocities.com/ko6bb/
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Merced, Central California, 37.3N 120.48W CM97sh