I am interested in having a rapid set up multi-band vertical for Field
Day and EMCOMM. If I use the Hy-Gain sixty four foot (64') push up
mast as the radiator and an ICOM AH-4 as the automatic antenna tuner
is this likely to be an effective approach to having a rapid set up
multi band vertical? Will I need radials? Should they be elevated or
can they lie on the ground? Since the total length of the radiator is
less than a 1/4 wave on eighty meters at say 3.6 MHz will that make
the antenna ineffective on eighty meters?

Second question would four of those sixty four foot masts make an
effective forty meter four square. Yes I realize that it would cost
eight hundred dollars for the masts alone before the cost of
controller, remote, phasing coax, and control cable. Once again would
radials be required for forty meters.

I've only been back in radio for a few years after very long gap so
I'm starting over and finding the learning curve a little steeper than
I remember.
--
Tom Horne, W3TDH

On Wed, 7 Apr 2010 20:09:56 -0700 (PDT), Tom Horne
wrote:

I am interested in having a rapid set up multi-band vertical for Field
Day and EMCOMM. If I use the Hy-Gain sixty four foot (64') push up
mast as the radiator and an ICOM AH-4 as the automatic antenna tuner
is this likely to be an effective approach to having a rapid set up
multi band vertical?

Hi Tom,

Yes.

Will I need radials?

Yes.

Should they be elevated or
can they lie on the ground?

Yes.

Since the total length of the radiator is
less than a 1/4 wave on eighty meters at say 3.6 MHz will that make
the antenna ineffective on eighty meters?

No.

Second question
5th, actually.
would four of those sixty four foot masts make an
effective forty meter four square.

Yes.

Yes I realize that it would cost
eight hundred dollars for the masts alone before the cost of
controller, remote, phasing coax, and control cable. Once again would
radials be required for forty meters.

Yes.

I've only been back in radio for a few years after very long gap so
I'm starting over and finding the learning curve a little steeper than
I remember.

You are still on the level wit the climb to come. There are a LOT of
details to make those simple answers work.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Wed, 7 Apr 2010 20:09:56 -0700 (PDT), Tom Horne
wrote:

I am interested in having a rapid set up multi-band vertical for Field
Day and EMCOMM. If I use the Hy-Gain sixty four foot (64') push up
mast as the radiator and an ICOM AH-4 as the automatic antenna tuner
is this likely to be an effective approach to having a rapid set up
multi band vertical?

Hi Tom,

Yes.

Will I need radials?

Yes.

Which of course make rapid set-up somewhat less rapid.



Should they be elevated or
can they lie on the ground?

Yes.

Side route here, can be skipped to remain strictly on topic.

Ohh, Ohh! I can segue into my radials burying method. Banned in several
countries!

Beyond Richard's concise answer, Elevated radials are kind of a PITA,
and the stuff that neighborhood Antenna bans are based on. And for this
use, they are also going to be in the way.

I'd also note that one method of laying radials is easy, but not so
good. I tried laying half of my radials laying the lines on the ground,
held in place with ground staples. It works well technically, for
practical purposes, not so good.

Raking the yard is a great way to lift the staples and the rake pulls
the wires up also.

I'm a big fan of shallow trenching.

Now on to my trenching method......

All those years of organized sports have taught me many things-
Sportsmanship, Teamwork, Goal setting and achievement, and especially
how broken bones, pulled tendons, and ligaments can conspire to make
life a little painful as the years go by.

Anyhow, hand digging a trenches and laying the radials is really painful
for me.

And renting a professional trencher just goes against my Hamness, M R
expensive!

The following is a description of a method I have used, and not a
suggestion that anyone actually do this. As they say on Mythbusters,
Don't do this at home - are you crazy? Never use a tool for other than
it's intended purpose. Do not use sharp things - ever. You have been warned.

So my solution is using an inexpensive electric chain saw to do the
trenching with. Simply start at the ground plate of your vertical, and
dig a trence with the chain saw. Works a trick! Lay the radial wires in
and cover them back up.

This is needless to say, rather hard on the chainsaw blade, and probably
the chain bar.


I repeat, don't ever try this method. It's dangerous.

Since the total length of the radiator is
less than a 1/4 wave on eighty meters at say 3.6 MHz will that make
the antenna ineffective on eighty meters?

No.


Second question
5th, actually.
would four of those sixty four foot masts make an
effective forty meter four square.

Yes.

Yes I realize that it would cost
eight hundred dollars for the masts alone before the cost of
controller, remote, phasing coax, and control cable. Once again would
radials be required for forty meters.

Yes.

I've only been back in radio for a few years after very long gap so
I'm starting over and finding the learning curve a little steeper than
I remember.

You are still on the level wit the climb to come. There are a LOT of
details to make those simple answers work.

Back on topic


For emergency work, simplicity is mandatory. I see the idea of setting
up multiple masts and radials on location as an unneeded complication,
and a failure point as well.

I'd also be inclined to have different antennas for each use.

And while it's heresy in here, if you want ease of tuning (or complete
lack thereof), you might give some thought to a T2FD folded dipole
antenna. Not a particularly great antenna, but wide band, and you make
up for it's inefficiency by running legal limit power.

Otherwise give some thought to dipole antennas, perhaps a doublet, and
use an autotuner on it. A couple masts, amybe those fiberglass pole
types and you should be good.

If you really want directional power on 40 meters, look into a portable
mast and a 40 meter beam. Coupled with full legal limit power, you'll
make your own propagation!

I think that outside of a permanent EC command center, simple and quick
is the order of the day.

- 73 de Mike N3LI -

On Apr 8, 1:13*am, Richard Clark wrote:
On Wed, 7 Apr 2010 20:09:56 -0700 (PDT), Tom Horne
wrote:

I am interested in having a rapid set up multi-band vertical for Field
Day and EMCOMM. *If I use the Hy-Gain sixty four foot (64') push up
mast as the radiator and an ICOM AH-4 as the automatic antenna tuner
is this likely to be an effective approach to having a rapid set up
multi band vertical? *

Hi Tom,

Yes.

Will I need radials? *

Yes.

Should they be elevated or
can they lie on the ground? *

Yes.

Since the total length of the radiator is
less than a 1/4 wave on eighty meters at say 3.6 MHz will that make
the antenna ineffective on eighty meters?

No.



Second question
5th, actually.
would four of those sixty four foot masts make an
effective forty meter four square.

Yes.

*Yes I realize that it would cost
eight hundred dollars for the masts alone before the cost of
controller, remote, phasing coax, and control cable. *Once again would
radials be required for forty meters.

Yes.

I've only been back in radio for a few years after very long gap so
I'm starting over and finding the learning curve a little steeper than
I remember.

You are still on the level wit the climb to come. *There are a LOT of
details to make those simple answers work.

73's
Richard Clark, KB7QHC

Richard
Please share the rest of the story. If we lay out multi length
radials for the middle of each band, say four of them, and feed the
vertical with the auto tuner would we be able to make it work on
eighty, and forty? When we use a half wave end fed zep in the form of
a J pole on two meters we don't need a counterpoise. If I extend this
mast to a half wave on forty will I still need a counterpoise?
--
Tom Horne, W3TDH

Tom Horne wrote:


Richard
Please share the rest of the story. If we lay out multi length
radials for the middle of each band, say four of them, and feed the
vertical with the auto tuner would we be able to make it work on
eighty, and forty?

You'll need to have some loads on the vertical also.

When we use a half wave end fed zep in the form of
a J pole on two meters we don't need a counterpoise. If I extend this
mast to a half wave on forty will I still need a counterpoise?

That will be one interesting antenna.

Is there some reason that you are fixing on a vertical?

- 73 de Mike N3LI -

On Thu, 15 Apr 2010 23:26:55 -0700 (PDT), Tom Horne
wrote:

Richard
Please share the rest of the story. If we lay out multi length
radials for the middle of each band, say four of them, and feed the
vertical with the auto tuner would we be able to make it work on
eighty, and forty? When we use a half wave end fed zep in the form of
a J pole on two meters we don't need a counterpoise. If I extend this
mast to a half wave on forty will I still need a counterpoise?

Hi Tom,

Thanx for something more specific that we can get our teeth into.

If you lay out radials that are tuned, such as you suggest, then you
wouldn't need an autotuner. There is, of course, the state of tune in
the radiator that needs to be accounted for, and I suppose the
autotuner would be put to work in that regard.

If so, then you are putting too much effort into the tune of the
radials. On the third hand, it doesn't hurt in the overall effort.

If you are going to have an autotuner (is this at the base of the
radiator, or back in the shack?); then there is a simpler and probably
more efficient use of the radial wire.

Over the years, the topic of how many and how long of radials with a
horizontal has had so many variables that the discussion ran to
examining the trivial instead of being useful. The useful advice is
to lay down as many radials as you can, but with a couple to three
dozen being a comfortable upper limit instead of the classic 120.
Their length should be equal to the radiator's height.

This doesn't make for a "tuned" vertical (except, perhaps, on some
frequency that probably is not in a Ham band if the height of the
antenna is ad-hoc); but it will be as efficient as is practicable. You
will still have to tune it. You will still suffer transmission line
loss related to the SWR exhibited at the feedpoint. It can be
unmanageable if its dimension approaches half-wave. Some of these
negatives can be managed by tuning the feedpoint with matching and
this is why I asked where the autotuner was located.

You anticipate the half-wave in your last question. The classical
answer there is no, you won't need a standard ground treatment. But
if you don't have some thing there, then tuning may become a chore
because the radiator, whatever its length, is always HALF of the
system. The radials typically are thought of as the other half. If
you don't have any, your transmission line will take up that function
in one way or another, and often to your annoyance.

As for the JPole discussion. Many who crow about their being simple
tunes and there being no problems with matching, some are simply
experiencing the transmission line being brought both into the tune
and the radiation. The second part of that equation lengthens the
overall radiator and sends the signal skyward. Yes, it tuned up fine,
but you then have a deaf antenna - suitable for the local repeater,
but so is an elevated rubber ducky.

73's
Richard Clark, KB7QHC

On Fri, 16 Apr 2010 10:19:40 -0700, Richard Clark
wrote:

Over the years, the topic of how many and how long of radials with a
horizontal has had so many variables that the discussion ran to
examining the trivial instead of being useful.

Somehow, that didn't come out right.

The number and length of radials is, of course, confined to the
discussion of a vertical antenna.

The number of variables in this relates to frequency, match,
efficiency, loss (which at first blush the last two "seem" to be about
the same thing), and (incorrectly) launch angle.

Another point that occurred to me: The notion of a tuned radial, and
it laying on the ground is an exercise in futility. The proximity of
ground is going to seriously detune the radial which will mock your
effort. Tuned radials are more a property of elevated verticals. Some
commercial verticals which come with tuned radials, or where you will
be expected to supply them, have a tacit expectation of your also
mounting the antenna some appreciable distance above ground.

73's
Richard Clark, KB7QHC

Tom Horne wrote:
I am interested in having a rapid set up multi-band vertical for Field
Day and EMCOMM. If I use the Hy-Gain sixty four foot (64') push up
mast as the radiator and an ICOM AH-4 as the automatic antenna tuner
is this likely to be an effective approach to having a rapid set up
multi band vertical?

Yes..
You don't need that much height, though.. the loss in radiation
effectiveness going from 1/4 wavelength (20m long) to 1/8 wavelength
(10m) isn't all that big a deal. It's when you get down to the 1/20th
wavelength and the feedpoint Z gets very wild that you have problems
with loss in the matching network.


Will I need radials? Should they be elevated or
can they lie on the ground?

Yes.. you do need radials. Laying on the ground is just fine. Get some
very flexible stranded insulated wire (the kind with lots of fine
strands is better.) and figure a way to rapidly throw it out and store
without tangling. I've thought about spring return reels.

3 or 4 makes a huge difference over 1 or 2. after that, it's a bit of
diminishing returns.. You'd be better off just doing what the people who
do this for a living (rapid deploy HF comms) do.. jack up the Tx power.

BTW, a better approach than a vertical might be a inverted V dipole from
the top of your 60 foot pole. MUCH better radiation effectiveness
because of H polarization..

Since the total length of the radiator is
less than a 1/4 wave on eighty meters at say 3.6 MHz will that make
the antenna ineffective on eighty meters?

Nope.. it's the loss in the tuning network that's the thing to worry
about.. you could make a lumped matching network to feed with your
autotuner if you're worried..


Second question would four of those sixty four foot masts make an
effective forty meter four square. Yes I realize that it would cost
eight hundred dollars for the masts alone before the cost of
controller, remote, phasing coax, and control cable. Once again would
radials be required for forty meters.

Radials are (almost) always required for verticals. even if you don't
install them, your feedline shield will act as a radial with
unpredictable and usually undesirable effects.

Running a 4 square with autotuners at each element is VERY difficult (if
not impossible).. the tuner changes the phase shift, and the interaction
from the other antennas will screw up the auto adjustment algorithm.



I've only been back in radio for a few years after very long gap so
I'm starting over and finding the learning curve a little steeper than
I remember.
--
Tom Horne, W3TDH

On Apr 8, 1:16*pm, Jim Lux wrote:


BTW, a better approach than a vertical might be a inverted V dipole from
the top of your 60 foot pole. * MUCH better radiation effectiveness
because of H polarization..

Much easier to deal with. You really don't want to have to deal
with radials at a field day. And using an antenna tuner to match
a vertical is not the greatest way to go about it.
Then you have the radiator height issue.. A 64 foot mast is too
tall for most of the higher HF bands. So it's not going to be too
practical for multi band use unless it's only for the lower bands.
Heck, it's slightly tall even to be a 5/8 wave on 30m...
It's going to be fairly useless as a vertical on 20m and up..
High angle lobes..

If it were me, I'd use the mast to support dipoles for each band
to be used. I feed them all with a single coax and spread the
legs apart at right angles to minimize interaction.
Or one could use a multi band dipole of some type.
One method I used to use camping was the "jumper"
dipole. IE: I'd run a 80m length dipole, but have insulators
breaking it up into higher band dipoles. For 80m, they would
all have jumpers across them.
For higher bands, you would use remove the jumper across the
insulator to shorten the length.
But I prefer the parallel dipoles for FD use, and I almost always
have enough room to do it. That way I have instant band changing
with no retuning, fiddling, etc..
If I were to use a vertical for all bands, I'd probably go with some
type of elevated 1/2 wave design that didn't require radials.
But except for far off DX, I would prefer the dipoles.
The bulk of FD contacts are not going to be DX on the lower
bands. You would be better served with the NVIS pattern of a
dipole on 40, 80 meters. An 80 or 40 meter dipole will work quite
well if supported at 60 ft at the apex. Really doesn't have to be that
high, but if you can get them up to 60 ft, they will work well.
Even to most DX.

On Apr 8, 2:16*pm, Jim Lux wrote:
Tom Horne wrote:
I am interested in having a rapid set up multi-band vertical for Field
Day and EMCOMM. *If I use the Hy-Gain sixty four foot (64') push up
mast as the radiator and an ICOM AH-4 as the automatic antenna tuner
is this likely to be an effective approach to having a rapid set up
multi band vertical?

Yes..
You don't need that much height, though.. the loss in radiation
effectiveness going from 1/4 wavelength (20m long) to 1/8 wavelength
(10m) isn't all that big a deal. *It's when you get down to the 1/20th
wavelength and the feedpoint Z gets very wild that you have problems
with loss in the matching network.

* Will I need radials? *Should they be elevated or

can they lie on the ground? *

Yes.. you do need radials. *Laying on the ground is just fine. *Get some
very flexible stranded insulated wire (the kind with lots of fine
strands is better.) and figure a way to rapidly throw it out and store
without tangling. I've thought about spring return reels.

3 or 4 makes a huge difference over 1 or 2. *after that, it's a bit of
diminishing returns.. You'd be better off just doing what the people who
do this for a living (rapid deploy HF comms) do.. jack up the Tx power.

BTW, a better approach than a vertical might be a inverted V dipole from
the top of your 60 foot pole. * MUCH better radiation effectiveness
because of H polarization..

Since the total length of the radiator is

less than a 1/4 wave on eighty meters at say 3.6 MHz will that make
the antenna ineffective on eighty meters?

Nope.. it's the loss in the tuning network that's the thing to worry
about.. you could make a lumped matching network to feed with your
autotuner if you're worried..



Second question would four of those sixty four foot masts make an
effective forty meter four square. *Yes I realize that it would cost
eight hundred dollars for the masts alone before the cost of
controller, remote, phasing coax, and control cable. *Once again would
radials be required for forty meters.

Radials are (almost) always required for verticals. even if you don't
install them, your feedline shield will act as a radial with
unpredictable and usually undesirable effects.

Running a 4 square with autotuners at each element is VERY difficult (if
not impossible).. the tuner changes the phase shift, and the interaction
from the other antennas will screw up the auto adjustment algorithm.



I've only been back in radio for a few years after very long gap so
I'm starting over and finding the learning curve a little steeper than
I remember.
--
Tom Horne, W3TDH

Jim
I had no intention of running a four square with four auto tuners.
Perhaps I should have put that inquiry into a separate posting for the
sake of clarity. We built a four square for field day two years ago.
Because the masts that we had then were only thirty feet high a kind
of capacitance hat was built into the guy lines. We had very good
performance from that four square until a severe thunderstorm
destroyed it. I was wondering if having sixty four foot masts would
allow us to adjust the height to resonance on forty meters so that the
four masts themselves could serve as the elements of the four square.
Since a half wave at 7150 kHz is nearly sixty seven feet I would have
to add three feet worth of additional tubing in order to get a
resonant half wave antenna. I had thought that half wave verticals
did not require a counterpoise was I misinformed? If a counterpoise
is needed it wouldn't be too hard to throw out four radials for each
mast. I was just looking for a quick way to put up a four square and
these aluminum masts seemed like they might fill the bill.
--
Tom Horne