Doug Smith W9WI wrote in
news
Strangely enough, I took absolutely NONE of these precautions - and my
mobile is working nicely. (that doesn't mean I recommend ignoring
Mike's points!)

I'm even running it from the lighter outlet. Figured it would be OK
for the ride home from Milwaukee running 20 watts or so. Kept
creeping up the power, I'm now at 80 watts (all bands) & not a hint of
trouble.

Again, I don't recommend it though!

The biggest source of QRN are leaky powerline insulators. Next
biggest source are passing semis. (last time I was HF mobile, semis
were quiet. Obviously something has changed in the typical truck
engine?)

On Thu, 17 Apr 2008 13:56:06 -0400, Michael Coslo wrote:
Oh, and by the way, the antenna appears to work "very well", at least
I've gotten good signal reports on 40 and 20, and reasonably good
ones on 75 meters also. It seems to make use of the limited
efficiencies we see with short HF aerials.

My Hamsticks are quite effective on 40 - can work pretty much anyone I
can hear if there isn't a pileup, and sometimes even when there is.
Managed to work a VK6 on 40 at sunset on my way into town a few months
back - that's darned near the antipodes from here. Managed to work
VP6DX on 80 from the car! Strangely 20 doesn't work quite so well,
though I still work plenty of DX.


Interesting! Your car being much more quiet might be the result of a
couple things. It is quite possible that you done good in the purchase.
Another possibility is that the bugcatchers are kind of a tour de force
in mobile antennas, and are designed to push every parameter in order to
maximaze efficiency as much as possible in the HF-unfriendly dimensions
available. High-Q coils (which even screwdrivers lack) and the necessary
short lengths of the entire antenna make all mobile HF setups pretty
marginal.I'm one inch short of the maximum height allowed for a vehicle
on US roads. The penalty for this is that the bugcatcher tunes extremely
sharply. I have 2 taps on the coil for 75 meters, and I'd probably need
several more to extend to 80 meters. On 40 and up, one tap per band is
usually sufficient.

http://www.w5dxp.com/shootout.htm

Has some results of a shootout of various mobile antennas.

Now all that being said, there is a lot of work in putting my HF mobile
setup together. I wanted/needed to tweak out every bit of performance
available for mobile contesting, and was willing to put the time into
it, which ended up being quite a lot of time. I did get to try it out
in the CAQSO party, and it worked okay on 20 meters, PA to CA. I got
good signal reports up and down the east coast on 40. On 80, well, they
didn't ever ask me to repeat myself. But anything below 40 meters is
dicey in operating mobile. I didn't get to use it in the PAQSO which was
my main reason for putting it together, due to a death in the family.
Later this year, I'll do a more scientific test, as much as one can be
done with antennas by someone without access to an antenna range....

And oh yeah - the bugcatcher is quite a sight, especially on a little
Suziki Vitara, even more so, with a 20 inch capacity hat on it. Not
everyone wants to look like that.

- 73 de Mike N3LI -