Hi Chris,
Yes, at one time Lich/ETP, Dino/KNX and I did a lot of comparisons and tests with mobile antennas on 75M.
Most of us had built homebrew versions of Bugcatchers and tried many other beefed up/ homebrew mobile versions.
You will find on 75M that the Hamstick is down about 6db from a full blown Bugcatcher. And, a simple 9' whip with modest B&W coil is within 2-3 db of the BugCatcher.
You can only do so much with any vertical whip portion of the mobile antenna since the vehicle's ground is the limiting and lossy part of the equation. I even tried using a full sized 60' vertical next to the car and saw little or no improvement that I cud measure against the full 11' bugcatcher. This is because instead of a nice 10 ohms or less ground radial system to work against, a car's ground plane might present 100++ ohms or who knows? Remember that a mobile whip on 75M has an input impedance down in the single digit ohms. So, a 9 ohm antenna into even a great 9 ohm ground system is a 3db loss already.
I once compared my vehicle on 75M against a full sized dipole at 60'... A/B swirtched them on 75M. The dipole was always 15-20db louder. That is the hit you take mobile. This was late afternoon when the mobile vertical works the best and the lower angle is an advantage. Use a Hamstick and it will become 21-26db down.
But, 6db is not such a big deal compared to the Bugcatcher on 75M. ie, You can still work all the same stations, but it will just seem like you are running 1/4 the power out and the other station is running 1/4 the power too...
![Grin](http://amfone.net/Amforum/Smileys/classic/grin.gif)
On the higher bands the vehicle's ground plane is more efficient. You will find the various whips get closer in performance since they become more "full sized".. After all, a 9' whip is a full 1/4 whip on 10M, so the various shortie whips tend to catch up to the "bugcatcher" types. Guys with tractor trailers do outstanding on 40-10M cuz of the huge ground plane. A low angle from the vertical on the higher bands is a natural too.
The ultimate 75M mobile setup was when Warren/K2ORS pulled 60' wire radials behind his car going down the highway. It worked great until cars behind him started breaking off the wires...
T