You are not asking for the moon. What you want is a simple, compact,
reliable antenna for both 144 and 440 MHz.. Having done a fair amount of
that sort of RACES/ARES stuff, here's what I'd advise you.

Go down to your local radio parts store, Rat Shack if that's all you've got
and get yourself a female BNC chassis connector (UG-1094, RS # 278-105).
Get a couple of quality male BNC cable connectors while you are at it.
Unfortunately for you, RS doesn't sell anything but that twist-on solderless
crap for male BNC, so you may wind up buying them mail order.

Get yourself four 3/8" solder lugs and five 19" pieces of solid #14 copper
wire (strip house romex if you have to).

To each of the four solder lugs, solder one end of the #14 wire. These will
be the four ground plane wires. THe fifth piece of #14 will connect to the
solder cup on the bottom of the female BNC chassis connector to become the
radiating element.

Now put those four solder lugs over the radiating element and over the
threads on the connector. Use the nut that came with the connector to
fasten the solder lugs, each at approximately 90° from each other (a small
crescent wrench or dedicated 1/2" wrench needs to be part of your permanent
tool kit). Bend them down at about a 45° angle.

Take the two male connectors and make an RG-58 cable to run from your radio
to where you want to put your antenna. Connect one end of the cable to your
radio and the other end to the UG-1094 connector.

You want to move the antenna? Disconnect the cable. Grab your wrench and
pull that nut off. Take off all 4 ground plane wires. Bundle them up
around the radiating element. Reassemble in the new location. Ten seconds
up, ten seconds down.

You want to use it in the field outside? Bend a small hook (no more than
1/4" long) in the radiating element. Tie a roll of heavy twine to the hook
and bend the hook shut. Take the roll of twine and throw it around the
highest tree limb you can find. Hoist that sucker up and you are on the
air.

We can dick around with a mounting bracket on the UG-1094 threads if you
want to make a permanent installation out of it.

(By the way, you are operating close enough to the third harmonic of 144 on
440 that the antenna will perform quite well on both frequencies.)

Jim









"Chuck James" wrote in message
t...
I know I could just go buy a mag-mount mobile antenna, but would it be
possible or even practical to build a J-pole type or vertical (without long
radials) antenna for 2m/70cm, out of welding rod, which could be small
enough to be easily portable and used inside different rooms? Our local
RACES is trying to set up a volunteer communications network inside several
different city and county offices to assist in emergencies. I have
searched (a little) for such a design, and found something similar, made
out of TV line, but would prefer something that could be made free standing
and as small as practical. The Welding Rod antennas made with 45 degree
radials are a little bulky to move through congested hallways. The idea is
to make it portable enough to move from room to room as needed. Long
radials would impede moving through hallways.
Thanks in advance, KE5GEO

RST Engineering wrote:
(By the way, you are operating close enough to the third harmonic of 144 on
440 that the antenna will perform quite well on both frequencies.)

It will even perform well as a satellite antenna on
440. EZNEC says it has a TOA of about 45 degrees.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
RST Engineering wrote:
(By the way, you are operating close enough to the third harmonic of
144 on 440 that the antenna will perform quite well on both frequencies.)

It will even perform well as a satellite antenna on
440. EZNEC says it has a TOA of about 45 degrees.

Hmmm. In some cases, would be nice to keep more of that signal terrestrial.

Regards,
JS

That's why you bend the radials down at a 45. It bends the pattern right
along with it.

Jim



"John Smith I" wrote in message
...


Hmmm. In some cases, would be nice to keep more of that signal
terrestrial.

Regards,
JS

John Smith I wrote:
Cecil Moore wrote:
RST Engineering wrote:
(By the way, you are operating close enough to the third harmonic of
144 on 440 that the antenna will perform quite well on both
frequencies.)

It will even perform well as a satellite antenna on
440. EZNEC says it has a TOA of about 45 degrees.

Hmmm. In some cases, would be nice to keep more of that signal
terrestrial.

That's the subtle point I was trying to make. To keep
the TOA low, the antenna should not exceed 5/8 WL.
6/8 WL raises the TOA. That's not optimum for hitting
repeaters unless they are on very high, very close
mountains.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
...
That's the subtle point I was trying to make. To keep
the TOA low, the antenna should not exceed 5/8 WL.
6/8 WL raises the TOA. That's not optimum for hitting
repeaters unless they are on very high, very close
mountains.

Cecil:

OK. No problem, subtle is all yours ...

But, remember, I get sarcastic and blunt! evil grin

Regards,
JS

"Cecil Moore" wrote in message
t...
John Smith I wrote:
Cecil Moore wrote:
RST Engineering wrote:
(By the way, you are operating close enough to the third harmonic of
144 on 440 that the antenna will perform quite well on both
frequencies.)

It will even perform well as a satellite antenna on
440. EZNEC says it has a TOA of about 45 degrees.

Hmmm. In some cases, would be nice to keep more of that signal
terrestrial.

That's the subtle point I was trying to make. To keep
the TOA low, the antenna should not exceed 5/8 WL.
6/8 WL raises the TOA. That's not optimum for hitting
repeaters unless they are on very high, very close
mountains.
--
73, Cecil http://www.w5dxp.com

Yup, the peak of the main lobe is elevated. ... but my 144 copper pipe
j-pole does put sufficient 440 energy toward the horizon that I am often
able to hit a repeater more than 70 miles away (Santiago Peak in Orange
County CA from southern San Diego County). Power out is around 4 watts from
a Yaesu FT-530.

Just now I tried Santiago and didn't hear back, so I tried 449.08 on Palomar
Mountain, 45 miles away, with a half watt and bought it up. Antenna is only
20 ft above ground; house is around 510 ft above sea level on a small rise.

Sal M. Onella wrote:
Yup, the peak of the main lobe is elevated. ... but my 144 copper pipe
j-pole does put sufficient 440 energy toward the horizon that I am often
able to hit a repeater more than 70 miles away (Santiago Peak in Orange
County CA from southern San Diego County).

Yep, paraphrasing Roy:
All antennas emit energy at all angles.

I just don't like to waste 10m/VHF/UHF energy
at high angles.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
...
I just don't like to waste 10m/VHF/UHF energy
at high angles.

Cecil:

And, neither do I. (well, 11m band--sometimes. Just for medicinal
purposes, mind you. evil grin)

I have pursued the "Ultimate 10M Antenna", and a yaga or quad is/are
great. However, I like a omni to listen for traffic on. And, when
there are high winds, I like to point those directional antennas into
the wind. (have stripped too many rotor gears and suffered too much
damage in past decades)

Like you point out, and I concur, the perfect Omni which throws no rf to
the sky is elusive ... strange too, we can do it with light.

I have gotten used to the "RF GODS" extracting their portion of my rf
field to their realms in the sky (sometimes they toss a bit back to
australia though, I like the women there )

Regards,
JS

And I did not mean to imply that you couldn't use brazing (not welding) rod,
which is nothing but brass and a little more to make the elements. IT
certainly makes a STIFFER antenna, but copper wire is a lot easier to work
with.

Jim



"Cecil Moore" wrote in message
et...
RST Engineering wrote:
(By the way, you are operating close enough to the third harmonic of 144
on 440 that the antenna will perform quite well on both frequencies.)

It will even perform well as a satellite antenna on
440. EZNEC says it has a TOA of about 45 degrees.
--
73, Cecil http://www.w5dxp.com