Mobile 2m/70cm antenna
 

I recently bought a Larsen 2m/70cm NMO mag-mount mobile antenna for my
truck. It's the first time I've ever owned a mobile antenna because I don't
do that much driving (I work from home). I don't have a mobile radio in the
truck, I just have an HT.

What I wanted to do was hook up my Icom W32A to the mobile antenna when I'm
in the truck. So, I put the mag-mount on the middle of the pickup roof and
started driving. I compared the mobile Larsen antenna to my Diamond RH77CA
HT antenna. What I noticed is that with the Diamond antenna on the HT
inside the truck, it consistently pulls in more signal (on both bands) than
the Larsen mobile outside the truck. The Diamond antenna is of course an HT
antenna, so it's optimized for HT use.

Is this normal behavior for a mobile antenna hooked up to an HT? If it's
not normal, then this is not that great of a mobile antenna.

Rod KI7CQ

Mobile 2m/70cm antenna
 

There is something wrong in your setup or installation.

I use the Larsen dual band with great success!!

Do you have pinched coax? Do you have a broken coax connector? How is
the coax run from outside to inside?

Can you give us some details?

Rod Maupin wrote:

I recently bought a Larsen 2m/70cm NMO mag-mount mobile antenna for my
truck. It's the first time I've ever owned a mobile antenna because I don't
do that much driving (I work from home). I don't have a mobile radio in the
truck, I just have an HT.

What I wanted to do was hook up my Icom W32A to the mobile antenna when I'm
in the truck. So, I put the mag-mount on the middle of the pickup roof and
started driving. I compared the mobile Larsen antenna to my Diamond RH77CA
HT antenna. What I noticed is that with the Diamond antenna on the HT
inside the truck, it consistently pulls in more signal (on both bands) than
the Larsen mobile outside the truck. The Diamond antenna is of course an HT
antenna, so it's optimized for HT use.

Is this normal behavior for a mobile antenna hooked up to an HT? If it's
not normal, then this is not that great of a mobile antenna.

Rod KI7CQ

Mobile 2m/70cm antenna
 

I stuck the mag mount on the roof and ran the coax in through the sliding
window on the back of the cab, so as not to pinch the cable. I had to use a
UHF to BNC adapter to hook the cable to the HT.

I just checked and I don't see any pinched places in the coax.

Rod

Mobile 2m/70cm antenna
 

Rod Maupin wrote:
I just checked and I don't see any pinched places in the coax.

Hang an MFJ-259B or 269 on it and find out what's wrong.
--
73, Cecil http://www.qsl.net/w5dxp

Mobile 2m/70cm antenna
 

I'll have to get an MFJ meter and check it out. I've been putting off
buying one anyway. Seems like they would be nice to have.

Rod

Mobile 2m/70cm antenna
 

Rod Maupin wrote:

I'll have to get an MFJ meter and check it out. I've been putting off
buying one anyway. Seems like they would be nice to have.

Rod


Check with the local Ham Club. Someone there simply has to have one. You
know, the guy, who needs everything :-)

They are very nice!! I have the MFJ 259B. [I guess I'm the guy who has
to have everything grin]

If you live in Southern NH, Southern Me or Northern Ma I can meet you
and run a quick test.

Contact me OFF the list if it is suitable.

Mobile 2m/70cm antenna
 

Thanks for the offer Amos, but I live in WA state. Too far of a drive for
you.

I actually have my radio club meeting tonight. So, I'll have to ask
someone.

The main thing is that you told me it wasn't normal, which makes me feel
better.

Rod

Mobile 2m/70cm antenna
 

On Wed, 30 Nov 2005 11:24:47 -0800, "Rod Maupin"
wrote:

I recently bought a Larsen 2m/70cm NMO mag-mount mobile antenna for my
truck. It's the first time I've ever owned a mobile antenna because I don't
do that much driving (I work from home). I don't have a mobile radio in the
truck, I just have an HT.

What I wanted to do was hook up my Icom W32A to the mobile antenna when I'm
in the truck. So, I put the mag-mount on the middle of the pickup roof and
started driving. I compared the mobile Larsen antenna to my Diamond RH77CA
HT antenna. What I noticed is that with the Diamond antenna on the HT
inside the truck, it consistently pulls in more signal (on both bands) than
the Larsen mobile outside the truck. The Diamond antenna is of course an HT
antenna, so it's optimized for HT use.

Is this normal behavior for a mobile antenna hooked up to an HT? If it's
not normal, then this is not that great of a mobile antenna.

Rod KI7CQ


When I bought a similar antenna, a Larsen 2m/70cm mag mount (mine is
about 20 years old, but may be the same exact model as yours) anyhow,
I had to cut the vertical element with a file to get the SWR down,
using a Bird wattmeter. The antenna, as it came from the factory,
needed quite a bit of diddling before being resonant.

Have you checked SWR, and/or adjusted the vertical length?

Bob
k5qwg