markus wrote:
hi Nelson,

yes, it is a lot of work, you could just attach the magmount
to any metal object, patio table, metal railing or window a/c unit, etc.

Yea, I suppose you could... Arf.... :/

or for a few dollars and less work build a great 2m antenna
using #12 thhn wire and a few feet of pvc pipe.

With even less work and $$$, he could just build a ground plane
using 5 wires and a so-239 or whatever..

this is the half square, works great, it is directional.

Probably not what he wants for 2 meters, unless he can steer
the pattern.

http://cebik.com/vhf/hs.html

then you can try this one, the Moxon for 2m, little harder to make
but has similar gain to a 2 element yagi in less space and direct fed
with 50 ohm coax (like the half square is fed).

Antennas are small on 2m.. He could live a little and use 3 elements
and have a good bit more gain. But then he has to rotate the thing..
I recommend a easy 1/4 wave ground plane to start. It will work about
as well or better as any of the other "easy" vertical whips for 2
meters.
Attaching a 2 meter whip to a railing, table, AC unit , etc is going to
function in a fairly poor manner. The ground radials need to be
resonant to function properly. Would be much better to use 4 simple
quarter wave radials. You can slope them down at about 45 degrees
to get a better match, and maybe a tiny bit more gain.
MK

MK, this diagram is fantastic! I guess I should have explained to all
of you that as a college student I have more time than money, so it may
be a while before I can even afford the PVC and wire. I bet it will
outperform my mobile-dipole-on-a-stick, though!

Nelson

On Jan 16, 10:22 am, wrote:
markus wrote:
hi Nelson,

yes, it is a lot of work, you could just attach the magmount
to any metal object, patio table, metal railing or window a/c unit, etc.Yea, I suppose you could... Arf.... :/



or for a few dollars and less work build a great 2m antenna
using #12 thhn wire and a few feet of pvc pipe.With even less work and $$$, he could just build a ground plane
using 5 wires and a so-239 or whatever..



this is the half square, works great, it is directional.Probably not what he wants for 2 meters, unless he can steer
the pattern.



http://cebik.com/vhf/hs.html

then you can try this one, the Moxon for 2m, little harder to make
but has similar gain to a 2 element yagi in less space and direct fed
with 50 ohm coax (like the half square is fed).Antennas are small on 2m.. He could live a little and use 3 elements
and have a good bit more gain. But then he has to rotate the thing..
I recommend a easy 1/4 wave ground plane to start. It will work about
as well or better as any of the other "easy" vertical whips for 2
meters.
Attaching a 2 meter whip to a railing, table, AC unit , etc is going to
function in a fairly poor manner. The ground radials need to be
resonant to function properly. Would be much better to use 4 simple
quarter wave radials. You can slope them down at about 45 degrees
to get a better match, and maybe a tiny bit more gain.
MK

Nelson Blaha wrote:
MK, this diagram is fantastic! I guess I should have explained to all
of you that as a college student I have more time than money, so it may
be a while before I can even afford the PVC and wire. I bet it will
outperform my mobile-dipole-on-a-stick, though!


Someone else posted that.. Myself, I wouldn't use one of those on 2m.
Sure, it would work, but for about the same or less amount of work
you could have a small 3 el yagi.
I would not use a directional antenna unless you had an easy way to
turn it.
A ground plane is super cheap, and will do just fine. You can place
them
on a mast, hang them from ceilings, etc. I've got a ground plane hung
in my
attic for emergency use. With 2m FM, gain is not really that important.
Decoupling from the feedline is though. The decoupling with the GP will
be fairly decent. If you use an off size "counterpoise" to mount a whip
on,
it's not resonant, and generally will do a poor job vs a complete
antenna.
You will find in most cases like that, the decoupling from the feedline
will be
poor too.
I'd start with a simple 1/4 wave ground plane, and go from there.
All you need is a SO-239 and 5 pieces of wire about 19-20 inches long.
Most bend the lower ground radials down at about 45 degrees to
get a better match to 50 ohms. You can set one on a table unless
the coax is thick... :/
Can't get much cheaper than that, and it will work well. To me, the
half square is too much work, too little gain for 2m.. Good for HF
tho..
A 3 el yagi would clobber that thing on 2m, and isn't too much bigger..
MK