On 12 Aug 2006 01:02:27 GMT, Ed
wrote:




What are the pro's and con's of lengenthing a mobile antenna? I have a
travel trailer that I would like to operate from with a mobile vertical
antenna off the back bumper. I standard 8' Huslter type mobile antenna
would be poor with most if its length running parallel the back side of my
aluminum framed trailer body. Would it be benefitial to add about 15 or
so feet of mast to the antenna below the coil? Would an additional 15 feet
of mast below the coil prevent me from tuning to resonance with the
adjustable whip on top? If so, any suggestions as to materials to do
so?

PS: I'm only planning on operating 75M and maybe 40M.

Ed K7AAT


Ed, I am assuming you are operating from a fixed location as the
height would exceed that of many bridges on the highway.

Can you get to the roof of the motor home easily enough? If so, I
would mount a bracket on the roof with a quick-disconnect on it. Then
when you reach your location, you can just climb up and mount the
antenna there fro the duration of your visit. Then when mobiling,
move the antenna back to the bumper.

I have operated a lot of mobile 80 and 40 meters. First of all, don't
expect miracles, especially on 80 meters. The placement of either
antenna on the center of the roof of my car has always been noticeably
better than the bumper mount version. I now drive a van and the
antenna is mounted on side of the van. Again, it is much better on
the roof and tunes more easily there too. However, i cannot drive
with it on my roof (I use Hamsticks).

As for your specific question, I don't know the answer, but if you can
find a piece of extension to test it with temporarily, such as a piece
of copper pipe, you might get an answer at an inexpensive cost.

Good luck,
Buck
n4pgw

--
73 for now
Buck
N4PGW