Brian Kelly wrote:
In the case of your 110 foot flattop with it's 110 foot feedline and
for my specific purposes the "tuner" would be a pair of inline lo-loss
fixed coils with taps which are selectable with a simple two pole
two-position ceramic rotary switch. Or make it a three pole switch and
be able to ground the antenna. Three taps yields three slices, etc. A
tuner like that would be a whole bunch easier to build and use and
would require much less mechanical claptrap than the original pair of
variable caps scheme requires.

It's essentially moving the loading coils from the antenna to the
hamshack and, according to EZNEC, gives a 1.1:1 SWR from 3.6 to
4.0 MHz. SWR goes up to 1.5:1 on 3.5 MHz.

However if using your 110 foot run of ladderline and coils
configuration is a hassle but a 44 foot feedline would work Mr.
Boyle's design can be used to get the same basic performance results
with the caps. The thread has produdced a couple good approaches for
practical solutions for an old problem and they both go into my
keepers book.

It will be interesting to apply Mr. Boyle's design to your particular
two-segment problem.
--
73, Cecil, W5DXP



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Cecil Moore wrote in message
...
Subjects drift and split into different threads. If you don't like this
thread, don't read it. Simple as that.
--
73, Cecil, W5DXP

Geeez, Cecil, no need to get emotional about it...


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(Mark Keith) wrote in message . com...
Cecil Moore wrote in message ...
Mark Keith wrote:

**snip**

But for what he originally wanted as far as covering two parts of 80m,
with one antenna, I still would prefer paralleled dipoles, cut for
each section of the band. I would run them at right angles like a
turnstile. The SWR curve will look like a "W". Solves his problem, and
is still ultra efficient with no caps to diddle, weird feedline
combos' etc..Add 40m legs, also in parallel, and it's instant
bandchange between both parts of 80, and also 40. Won't have to do a
thing except dial the radio around...I think he said he's already got
the high bands covered...To me, thats the "perfect" antenna for his
problem, and what I would run in his case. But to each his own I
guess...

Mark as usual one size does not fit all. Particularly when antennas in
small back yards with limited antenna support options come into play.
Which is what I'm dealing with. If I had enough real estate available
to put up crossed coax-fed dipoles/vees I'd probably do that. But as I
pointed out earlier I don't have enough real estate, not even close.
So your solution is irrelevant here.

The jumper-to-bandswitch antenna would work IF one was (a) able to
drop and hoist the antenna quickly and conveniently (b) was inclined
to futz around in the dark to change bands. Which I'm not. I've
installed dipoles at this site before, the trees I use for supports
are gnarly beasts, simply dragging one insulator per end per weekend
thru the things is a major hassle. There are still a couple end
inulators dangling in 'em from previous (broken) antennas so that
elimimintes the quick up/down idea and hauling multiple insulators
and/or traps thru 'em.

I *might* have 20 & 15 covered *if* that antenna works. But I don't
know yet one way or the other so I'm still planning on an
off-the-shelf G5RV to cover my butt this time around unless a better
idea come up. I've used G5RVs before, they're far from my favorite
type antenna mostly because of the need for a wide-range ATU but they
do work and are applicable to a much wider range of installation
conditions and restrictions than any other type of coax-fed multiband
HF antenna that I know about.

MK

w3rv

Paul wrote:
Cecil Moore wrote:
Subjects drift and split into different threads. If you don't like this
thread, don't read it. Simple as that.

Geeez, Cecil, no need to get emotional about it...

No emotion there, Paul, just objective logic. It's like saying,
"If you don't like broccoli, don't eat it. Simple as that."
--
73, Cecil, W5DXP



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Brian Kelly wrote:
The jumper-to-bandswitch antenna would work IF one was (a) able to
drop and hoist the antenna quickly and conveniently (b) was inclined
to futz around in the dark to change bands.

I can (a) release the pulley on either end of my antenna or just pull
on the feedline to get at the jumper point. I have (b) a mercury
vapor arc-type nightlight in the backyard 10 feet distance from the
feedline.
--
73, Cecil, W5DXP




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In article ,
(Brian Kelly) writes:

In the case of your 110 foot flattop with it's 110 foot feedline and
for my specific purposes the "tuner" would be a pair of inline lo-loss
fixed coils with taps which are selectable with a simple two pole
two-position ceramic rotary switch. Or make it a three pole switch and
be able to ground the antenna. Three taps yields three slices, etc.

Or use relays. Switch the 50 ohm end of the coil to avoid high voltages. Two
relays yields four possible choices....

A
tuner like that would be a whole bunch easier to build and use and
would require much less mechanical claptrap than the original pair of
variable caps scheme requires.

Perhaps. An old electric screwdriver could be used to drive a pair of caps or
rollers, too. They're all over the place, discarded when the batteries go bad.

73 de Jim, N2EY

Cecil Moore wrote in message ...
Mark Keith wrote:
But to each his own I guess... MK

I prefer experimenting to operating.
--
73, Cecil, W5DXP

Oh, so do I. I like the antenna and rig setups, but I actually don't
like the operating part of it. I pretty much just sat around last
year, and let the rest of them have at it. I didn't do much as I felt
unusually lazy for some reason. :/ One reason was they switched to a
puter logging, keying, rig control, and all that mess, and I'd never
used it before. Was clumsy as heck to me...I think I almost prefer
doing it all manual...I've never liked contest type operating. To me ,
it's work. My idea of a better field day is sitting in a lounge chair
on one of the hill country rivers, in front of a smoker, maybe sipping
a cool one, "I only drink under the clinical supervision of a doctor",
doing pretty much nothing at all....Maybe a casual redneck yik-yak qso
every hour or so...:/ That fast contest type stuff gives me brain
damage after a while. But it's hard for me to avoid being drafted, as
I work CW fairly swiftly, and can rack up the points if I feel so
inclined...Thats why I never work fone. It's not viable pointwise when
I get half the points for fone, but work either about the same overall
speed...But, I usually feel inclined to relax...A friend of mine who
is also a CW op, N5XZ, he tears it up. Usually makes the most points
every year I think. But he likes that type of operating more than I
do. He'll stick in there a long time, where I'll usually flake out
after 2-3 hours on a good year.. MK

Cecil Moore wrote in message ...
Brian Kelly wrote:
The jumper-to-bandswitch antenna would work IF one was (a) able to
drop and hoist the antenna quickly and conveniently (b) was inclined
to futz around in the dark to change bands.

I can (a) release the pulley on either end of my antenna or just pull
on the feedline to get at the jumper point.

Ship me your back yard a few days before the last full weeklend in
June freight collect and I'll ship it back immediately the following
Monday.


I have (b) a mercury
vapor arc-type nightlight in the backyard 10 feet distance from the
feedline.

.. . . oughta make life on 160 really "interesting" . .

--
73, Cecil, W5DXP

w3rv

Cecil Moore wrote in message ...
Brian Kelly wrote:
In the case of your 110 foot flattop with it's 110 foot feedline and
for my specific purposes the "tuner" would be a pair of inline lo-loss
fixed coils with taps which are selectable with a simple two pole
two-position ceramic rotary switch. Or make it a three pole switch and
be able to ground the antenna. Three taps yields three slices, etc. A
tuner like that would be a whole bunch easier to build and use and
would require much less mechanical claptrap than the original pair of
variable caps scheme requires.

It's essentially moving the loading coils from the antenna to the
hamshack

That's OK, High Q loading coils are not necessairily bad things at
all. A couple decent-size airwound coils are *much* easier to come by
in the shack than they are up in the air and out in the weather. Plus
you can vary the L right in the shack.

and, according to EZNEC, gives a 1.1:1 SWR from 3.6 to
4.0 MHz. SWR goes up to 1.5:1 on 3.5 MHz.

I could definitely live with that.

However if using your 110 foot run of ladderline and coils
configuration is a hassle but a 44 foot feedline would work Mr.
Boyle's design can be used to get the same basic performance results
with the caps. The thread has produdced a couple good approaches for
practical solutions for an old problem and they both go into my
keepers book.

It will be interesting to apply Mr. Boyle's design to your particular
two-segment problem.

I'm not far enough along my modeling learning curve to be able to
model transmission lines yet but you're obviously right.

Assuming some full system modeling of the Boyle Special for basic
guidance, the availability of a 259B, another ceramic rotary switch
and a pile of silver mica caps what are the downsides of using fixed
caps vs. variable caps?

w3rv

Brian Kelly wrote:
... what are the downsides of using fixed caps vs. variable caps?

They're not variable and cannot compensate for rain, etc.
--
73, Cecil, W5DXP



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