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Old December 14th 05, 06:31 PM posted to rec.radio.shortwave
Dale Parfitt
 
Posts: n/a
Default To RHF, et al. Re Loops


"Telamon" wrote in message
...
In article TkAnf.6139$Jz6.1420@trnddc06,
"Dale Parfitt" wrote:


.................................................. ............................
..

I fully agree...Note the post I just made, before I read this one..
And a loop is most certainly *not* a quieter antenna than a dipole,
*except* in cases of corona problems. If there is no corona, or
static buildup, there is no advantage at all. And you would need to be

in the mountains like HCJB to really see the advantage. It was the
corona
problems at HCJB which led to the use of the loops at that station.
Had nothing to do with the antenna performance in itself.
Like I've said, RHF is an enthuthiastic sort, but he comes up
with some hokey ideas about antenna theory at times.
RHF, you need to invest in some good antenna books. IE: ARRL antenna
handbook, etc.. Your "intuition" is leading you astray...
MK

I agree totally. The W8JI link is very revealing of what I see daily
here. I
continually compare my 7' shielded loop w/ BB preamp to my 140' dipole.
Even
on 160M where the dipole is highly reactive (thus incurring some
additional
feedline loss) the dipole beats the shielded loop almost 100% of the
time.
To its credit, the dipole is close to 150' above the lake, thus ensuring
fairly low takeoff angles down to perhaps 3 MHz or so.

Where the loop comes into its own is below 500KHz- the deep nulls can be
placed on a noisy transformer (?) across the lake and used to reduce that
noise source. With that said, the 140' dipole would not be expected to
perform well at LF.


If the loop is significantly closer to the ground than the dipole then
it is an unfair comparison. Antenna height is a large parameter to beat
with another antenna.

--
Telamon
Ventura, California


The loop is vertically polarized- so takeoff angle is not effected by height
above ground.
In addition, I'm on a mountain top some 100' above a large lake.
Dale W4OP