Charles will have to speak to the TH-7, but certainly the Hy-Gain
monobanders like the 204BA, although having insulated driven elements,
were at DC ground through the beta match attached to the boom.
Also, in my non-scientific reference to a beam being "quieter" I meant
the noise generated by atmospheric phenomena, such as "precipitation"
noise, rather than the man made stuff that might be avoided by an
antenna being higher in the air.
In my not so humble opinion, there hasn't been sufficient work done on
the relative "quietness" of various antennas. My own observations have
told me that closed loops such as quads are *much* less susceptible to
precipitation static than yagis. And amongst yagis, DC grounded ones
are quieter than those with insulated elements. This represents only a
very few data points spread out over about 45 years of playing with
antennas...and I still don't know why I observed what I observed.
I wouldn't expect Force-12, Cushcraft, or KLM to advertise that quads
were quieter than yagis anymore than I would expect Lightening Bolt, Gem
Quad, or Cubex to say that quads are more trouble to maintain than
yagis. We probably can't look for enlightenment on this subject from
the commercial sector. It will have to come from the amateur ranks or
from academia. Or has it already been done and just not highly
publicized? L.B., have you come across anything on the subject?
I'm not sure what good it would do if the "facts" were known. Look at
the Double Bazooka. Sometimes it seems to me that the relative merits
of antennas are more a matter of religious-like faith than hard
evidence. Regardless of what is proved or demonstrated, I will be hard
pressed to ever fool with quads again. If, however, it can be
demonstrated that grounded yagis are significantly less susceptibel to
atmospheric and/or precipitation noise than those with insulated
elements, then that is something I could and would definitely make use
of.
73,
Ken K4XL
73,
Ken
Del Seay wrote:
>
> >My single band 10, 15, and 20 beams (HyGain 5 el) are much quieter than my
> >removed TH-7. And all the new ones are plumber's delight! de K4VUD
>
> So was the TH--7, wasn't it. Well, except for the DE.
> You don't suppose that pattern may be involved, do you?
> I find higher antennas to more immune from local manmade
> noise, due to the fact that the noise must travel further.
> de KL7HF
--
Ken K4XL
grimm@lynchburg.net
Boatanchor Manual Archive - ftp://198.28.36.115/pub
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