Colinear 2 meter antenna question
 

I'm using the Hustler CG-144 colinear antenna
with the radial kit. The antenna is 42' above
ground and fed with 35' of Flexi 4XL coax.

This antenna is apparantly a 1/4 wave phased into
a 5/8 wave and is working well.

My question is what impedance (SWR) would
this antenna sho on 446 mhz? I don't have a 440
mobile but I do have a VX-2R HT and I hooked
it up on 440 to this antenna and it seemed to
perform well.

Ken KG0WX

Ken Bessler wrote:
"My question is what impedance (SWR) would this antenna show on 446
MHz?"

An antenna operating on its 3rd harmonic may be roughly a 1/4-wave
connected to the drivepoint through an additional 1/2-wavelength of
antenna.

The 1/2-wave portion repeats the impedance it "sees" at its ends,
therefore the drivepoint "sees"the same impedance that the length in
excess of 1/2-wavelength presents. If this is a good match to the
drivepoint, as it well may be, you will have a low SWR.

Best regards, Richard Harrison, KB5WZI

Ken Bessler wrote:
I'm using the Hustler CG-144 colinear antenna
with the radial kit. The antenna is 42' above
ground and fed with 35' of Flexi 4XL coax.

This antenna is apparantly a 1/4 wave phased into
a 5/8 wave and is working well.

My question is what impedance (SWR) would
this antenna sho on 446 mhz? I don't have a 440
mobile but I do have a VX-2R HT and I hooked
it up on 440 to this antenna and it seemed to
perform well.

446/3 = 148.7 so a 2m antenna will often resonate on 440 MHz.
The trouble usually is a high radiation angle on 3x the
fundamental frequency for ordinary verticals. How the above
antenna would radiate on 446 MHz is an educated guess. My
guess is at a very high radiation angle. But if it hits the
repeater you want to hit, it's "working".
--
73, Cecil, W5DXP

On Wed, 17 Nov 2004 13:40:30 -0600, "Ken Bessler"
wrotF:

I'm using the Hustler CG-144 colinear antenna
with the radial kit. The antenna is 42' above
ground and fed with 35' of Flexi 4XL coax.

This antenna is apparantly a 1/4 wave phased into
a 5/8 wave and is working well.

My question is what impedance (SWR) would
this antenna sho on 446 mhz? I don't have a 440
mobile but I do have a VX-2R HT and I hooked
it up on 440 to this antenna and it seemed to
perform well.

Ken KG0WX


I was running a cgt-144 and when I got a dual band mobile I used it on
440. The swr was higher than I liked so I added an adjustable grounded
vertical element about a 1/4 wave long about 1.5" away from the
CGT-144. The idea was to turn it into an open stub j-pole on 440. I
was able to get the swr below 2:1 on the repeater input freqs and in
theory the 1/4 wave 2m section (3/4 on 440) would radiate as an end
fed 1/2 wave on 440. It didn't seem to hurt the 2m operation at all.
It didn't work as well on 440 as the dual band Comet CA-2x4SR that I'm
using now but it did work.

I'm also planning on using the CG-144 with radials as fixed station
antenna now that it's been retired from mobile service.

Mike kc9doa