Coaxial antenna question
 

You could try putting 4 ground plane elements off the SO-239 connector, I'm
told they are to help with standing wave problems. I've never used ground
plane antennas, but it wouldn't take much effort and could be worth a try.
I use the MFJ 269 antenna analyzer when building antennas and find that the
unit saves lots of time. Rollie

Coaxial antenna question
 

"Rollie" wrote in
:

You could try putting 4 ground plane elements off the SO-239
connector, I'm told they are to help with standing wave problems.

Repeating someone else's advice in this way is a detached recommendation,
and if you don't understand it, a questionable recommendation.

Attaching radials as you suggest turns the antenna into a regular ground
plane antenna. One expects the feed point impedance at resonance to be
around 35 ohms, which would result in a VSWR of 1.5 when fed directly by
50 ohm coax. Much the same outcome as feeding the coaxial dipole with 50
ohm coax.

I've never used ground plane antennas, but it wouldn't take much
effort and could be worth a try. I use the MFJ 269 antenna analyzer
when building antennas and find that the unit saves lots of time.

Sloping the radials can raise the feedpoint impedance, but I think Ed
wanted an antenna without radials for his particular application.

Owen

Coaxial antenna question
 

You could try putting 4 ground plane elements off the SO-239
connector, I'm told they are to help with standing wave problems.
I've never used ground plane antennas, but it wouldn't take much
effort and could be worth a try. I use the MFJ 269 antenna analyzer
when building antennas and find that the unit saves lots of time.
Rollie


Yes, I have done that, and they work very well. I found three
radials sufficient, and if bent down about 45 degrees the match was
perfect. However, for the application I am planning, the antenna must be
very portable.... ground plane radials "stick out" but the coaxial
skirted antenna has a very minimal foot print.... it can be packed in a
very tight space.... just like any pipe.

Tnx.

Ed K7AAT

Coaxial antenna question
 

"Ed" wrote in message
. 192.196...

You could try putting 4 ground plane elements off the SO-239
connector, I'm told they are to help with standing wave problems.
I've never used ground plane antennas, but it wouldn't take much
effort and could be worth a try. I use the MFJ 269 antenna analyzer
when building antennas and find that the unit saves lots of time.
Rollie


Yes, I have done that, and they work very well. I found three
radials sufficient, and if bent down about 45 degrees the match was
perfect. However, for the application I am planning, the antenna must
be
very portable.... ground plane radials "stick out" but the coaxial
skirted antenna has a very minimal foot print.... it can be packed in a
very tight space.... just like any pipe.

Tnx.

Ed K7AAT

A twinlead J-pole in a PVC pipe works well for this. Our club had one
on a post stabbed into the ground when we needed talk-in at the BBQ's.