Somewhere, G3TXQ stated that the values he calculated at
http://www.karinya.net/g3txq/chokes/ were subject to stray capacitance. It
doesn't take much to throw the values in his charts there way off.
That's another reason to not recommend chokes like that as a general
solution. Even for a single ba
On 10/22/2012 5:44 AM, Tom W8JI wrote:
If we look at a popular balun book, to explain why a test dipole at
1/4 wave height did not benefit from a balun, the author cooked up a
very strange theory about cable diameter in wavelengths relating to
balance. The author neglected looking at the distan
Guy,
I see K4XS as still being in the general case. That is because a
wavelength on 160 is 539 feet. He wound up going up 55 feet (a separate
TopBand thread) or 0.10 (a tenth) of a wavelength. That's short,
wavelength-wise, even if we throw in the reasonable if arbitrary 1/8 wave
point as the
Interspersed.
On Sun, Oct 21, 2012 at 9:01 AM, Tom W8JI wrote:
> I find after some interesting conversations that readers of posts
>> often read as if written to them. So I write my posts as to the
>> general audience. If an expressed situation is so specific as to be
>> exceptional to general
I find after some interesting conversations that readers of posts
often read as if written to them. So I write my posts as to the
general audience. If an expressed situation is so specific as to be
exceptional to general use, I reply in private.
K4XS had such a situation, as does **any case**
I hear what you are saying Guy.
Every vertical installation is a unique situation.
I dont have enough technical knowledge to determine
when my vertical antennas could do without a common mode choke.
I plan to continue using a choke on all my verticals to be safe.
73,
Bob
K6UJ
On Oct 20,
"Just DO the common mode choke on any vertical. Don't tempt Murphy."
I stand by my comments.
I find after some interesting conversations that readers of posts
often read as if written to them. So I write my posts as to the
general audience. If an expressed situation is so specific as to be
exc
Just DO the common mode choke on any vertical. Don't tempt Murphy.
1.) He has a vertical with the base 60 feet above ground, and it sounds like
the feeder drops vertically
2.) If the coax is 60 feet to ground, and has a surge impedance of around
500 ohms in common mode (it's a thick cond
" And you don't need a hail-mary super choke for the job. "
Hi Guy:
I'm going to try elevated radials on my shunt-fed tower. I was thinking
about constructing an "Ugly Balun" for the job with 4" PVC and Bury-Flex.
What kind of choke do you use / recommend ? About how much coax should be
wound on
Hi, Bill,
I would add that there is nothing good that can come of having coax pull
away from a vertical without a good common mode choking device of some
sort. You may get away without it, but if not you have lost. Lost dB,
picked up noise, changed pattern to favor noise sources.
If you have ra
I'll be putting up a T-top elevated vertical for 160 in the next couple of
days. The baser will be around 60 ft above ground and the Tee (about 40
feet long will be at about 170-180 ft...depending on the caternary sag.
There
will be 4 radials at 90 degrees to each other.
Question: Any type of
I'll be putting up a T-top elevated vertical for 160 in the next couple of
days. The baser will be around 60 ft above ground and the Tee (about 40
feet long will be at about 170-180 ft...depending on the caternary sag. There
will be 4 radials at 90 degrees to each other.
Question: Any type
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