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Old September 6th 12, 10:29 PM posted to rec.radio.amateur.antenna
Dave Platt Dave Platt is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 464
Default Ringo Ranger Problems

In article ,
John Ferrell wrote:

I cannot imagine what your problem is with the 2 meter CushCraft Ringo
Ranger. I have had the same one in service off and on since the late
70's. Easy to mount, easy to match, physically durable, priced real
close to the cost of the aluminum. The J-Pole is popular now days but
is not near the performer that the Ringo is. I have both! The Ringo on
a tower is not a good idea because it brings up too many repeaters on
a given frequency. Bad operating manners!
As far as the 12 element CushCraft Yagis are concerned I have a 440 &
2 M models and have found them to work just like the modeling programs
indicate. There will be a "lump" on the pattern that is not shown in
the model, presumably radiation from the Gamma match.


As I understand it, the basic Ringo antenna is a half-wave, end-fed
vertical dipole. A gamma loop at the bottom serves as the impedance
matching element.

The basic J-pole is fundamentally quite similar... it's a half-wave
vertical dipole, end-fed. The common versions of J-pole use one or
another variant of a shorted quarter-wave stub section as an impedance
match.

These two antenna types should, in principle, have very similar
radiation patterns (they're both half-wave radiators) and can have
similar problems with pattern-disturbing "RF on the mast" and "RF on
the feedline" (they're often grounded to the mast, and fed from a
50-ohm feedline without a choke). In some installations, the "RF
where you don't want it" condition could cause the antenna's pattern
to squint in directions where it doesn't do you all that much good,
and have a weaker signal directly out towards the horizon where most
of the repeaters probably are. In other installations (where the
feedline or mast presents a high or highly reactive impedance) you
wouldn't notice any problem.

The Ringo Ranger is a higher-gain antenna, with two vertically-stacked
radiating sections and a phasing stub between them. It looks to me as
if the two sections are 5/8 wavelength or a bit more. You'd get
several dB more gain towards the horizon with this configuration, than
you would get from a J-pole or an original Ringo.

The Ringo Ranger has no decoupling from the mast or feedline, and can
suffer from the same sort of pattern-squint as the Ringo and J-pole.

The Ringo Ranger II adds a decoupling section (a length of feedline
and a set of decoupling radials) which is supposed to prevent this
problem, and it would probably have the cleanest and sharpest
towards-the-horizon pattern of any of these antennas.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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