PAMNO (N2EY) wrote in message ...
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....

That would probably be the way to go. I'm big on keeping
dedicated-purpose tuners like this one would be out in yard right at
the end of the feedline instead of in the shack. Relays would work
fine and are easy to remotely control.

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.

I don't see any particular point to using continuously variable coils
and/or caps when the same job can be done with their much more
reliable and simpler fixed value eqivalents in situations like this.
High parts counts and moving widgets in any combination is trouble
looking for a place to start.

73 de Jim, N2EY

w3rv

In article ,
(Brian Kelly) writes:

(N2EY) wrote in message
.com...
(Brian Kelly) wrote in message
.com...
Cecil Moore wrote in message
...

The books give all sorts of figures for "open wire line". But many of
them are for the classic lines made of #14 copper spaced 4 to 6 inches
with ceramic spreaders every few feet. Brown poly TV twin lead with
rectangular holes punched in it is a whole 'nother ball game.
'Specially at high SWRs and when it's wet. Which may not be a
consideration in NTX but is a big consideration in EPA.

(a) It's only Field Day

Go down that road a little more and you're in a certain park I know of...

(b) If ya just gotta have "the real thing" it's out there for cheap:

http://www.w7fg.com/ant.htm

nice stuff!

It can be coiled into a big helix as long as the adjacent coils are
a couple of feet apart. You can run an insulated rope to the antenna
feedpoint and coil the ladder-line on the rope with the coils
tiewrapped
a couple of feet apart.

That's slick.

Until the rain falls or the wind blows

It rains on thousands of G5RVs every day all over the world and . . ?

And the loss goes up.

or somebody walks into it in
the dark.

. . welcome to Field Day antenna farms . .

One fella I knew useta always have an RCA phono jack arrangement in the coax
somewhere near the op table. Seemed odd until he told about the time somebody
drove across the site at 2 AM and the coax got caught in the guy's bumper....

The big question for any FD antenna is "how many QSOs"? All the
simulations and Smith charts don't count for any points - QSOs do.

Exactly. So ya get a bit more loss when it rains on a G5RV, who
cares??

Depends on whether it takes the rate down.

Lemmee cite a good recent example of why too many people fuss
too much with dB. here dB. there details.

I was watching ops at the N3RS multiop station during the ARRL CW DX
contest in March. Late in the contest the guy in the 20M seat was
knocking out contacts as a respectable rate. The xcvr was an FT-1000
and the amp was a big remote-controlled ACOM. After some considerable
amount of time he finally noticed that the amp had faulted and swithed
itself offline when he changed bands to get on 20M. He'd been running
barefoot the whole time without realizing it. The problem was sorted
out, the amp was reset and off he went again this time with full
power. His rate did not change by any discernable amount even though
his "losses" went down by what . . 12 dB?

OK, fine. On that band, in that contest, with that rig and op, the dBs didn't
make much difference. You wanna tell that gang to run low power next year? How
about QRP?

btw, I saw the 'RS farm from the PA TPK last week, not many dB wasted there!

So no, I am not gonna get my knickers in a twist over the collection
of incidental losses one runs into with FD antennas and tuners. As you
imply there are far more telling factors which determine the
effectiveness of any station.

Of course.

My
personal best is 629 QSOs with one 100W rig, one op, one mode, three
bands and two antennas. Coax fed trapper set up as inverted V for
80/40, quarter wave groundplane elevated 5 feet with 8 sloping radials
for 20.

Anybody here beat that on FD with only dipoles and verticals?

OK, change of topic here, I'm game. Anybody out there have well over a
hundred countries confirmed on both 80 and 40 by using just a single
length of end-fed wire for the antenna?

W2QHH, for one...;-)

Here's my main point in all this:

Whenever antennas are discussed, you will often see descriptions such as "we
did really well" or "outstanding performance" or some such. Particularly FD
antennas.

But what constitutes "outstanding performance" is usually not defined. For some
folks, making 10-15 QSOs per hour on FD when the band is wide open is
"outstanding performance". For others, making 2-3 times that rate under similar
conditions isn't "outstanding performance".

Patterns and simulations and SWR curves on websites are great stuff, but what
really matters to me in terms of "outstanding antenna performance" on FD is how
many QSOs you have in the log when it's all done.

73 de Jim, N2EY

N2EY wrote:
Patterns and simulations and SWR curves on websites are great stuff, but what
really matters to me in terms of "outstanding antenna performance" on FD is how
many QSOs you have in the log when it's all done.

Some of us regard outstanding performance as how many 807's
have been put away. :-)
--
73, Cecil, W5DXP



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----