Underground mobile antenna issues

[grinthock]

I love my 5/8 antenna, on 2M it gets out real well, but when I go under my building, the top 5 inches hit's the pipes.

I know there are knock back antenna's what other solutions have people here used for underground parking?

[va3wxm]

I use a Larsen nmo2/70b dual-band antenna (approximately 36" tall) for low-overhead situations. There are also 1/2 wave antennas around that are, well, a third shorter than your 5/8. The gain difference between the two is negligible.

[kf4sqb]

Unless you are going really fast, I don't think you will hurt the antenna. Or maybe the noise bothers you , like it does my wife.....

[grinthock]

Well there are two options as I see it....

The whip I have now is black painted copper core (standard Larsen) but the paint is pretty much gone now, from hitting the pipes.

Noise doesn't much bother me. But I figure if I goto a stainless whip it won't be "Damaged" like the copper one is. Plus it's going to be alot less subseptible to bending

[70351]

I also had the same problem when I used to have to park in an underground facility. I was using a black Larsen NMO-150 on the trunk and it scraped the pipes and ceiling in places, rubbing off the black paint exposing the copper core. I put a Larsen NMO-270 in it's place, which was shorter, and didn't have that problem any more. I found the gain on 2-meters to be the same as the longer two meter-only antenna.


Randy

[raymond345]

We have found in the past the 5/8 wave ground
plane antenna worked better for morning skip than
the 1/2 wave antenna.
We get a lot of inversion on 5/8 than what is
heard on the 1/2 wave.