Undeserved Bad Rap For Hamsticks?

[AJ1G]

After using these "Dummy Loads on a Stick" for about 4 years now, I feel that the subject nickname is unwarranted.  I  have worked all over the world on 40 CW mobile with 100 watts from my FT100D and a stick installed as shown below, first on my 97 Taurus and for the last few weeks, on its replacement, a 98 Volvo Cross Country.  Most recent DX on 40 CW/m was with another CW moble in Crete last week, and UU2CW in the Crimea yesterday at about 5PM our time, just as the EU stations started rollng in. (No doubt Josef's 4 EL yagi helped - he was very strapping on this end!)

I agree that the sticks are marginal on 75, but I was still able to maintain solid comms with Dale, KW1I on 3905 slopbuclet all the way home from Hosstraders last weekend, from late afternoon until about 10 PM.

For those of you who haven't seen this setup at Hosstraders, the sticks feed point is at the top of a Thule bike carrier pedestal that bolts into the trailer hitch receiver.  Keeps the antenna up in the clear, high and away from the car body, hopefully rasing feed point impedance, and minimzing  absorbtion losses.

Has anyone done any A/B comparisons of sticks vs something like a bugcatcher or screwdrivers, nearfield and/or longhaul, or know of any such info posted online?

[K1JJ]

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...

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

[W3SLK]

I have always been told that the 'Westerns' work well on 75. I used to see them for sale quite often but haven't seen one in a number of years. Wouldn't mind having one in case I find a place to put a mobile boatanchor in the Trailblazer.

[Tom WA3KLR]

About 8 years ago I did an A/B comparison between a ham friend's Hamstick and my Hustler mast with a standard 75 meter resonator installed.  The Hamstick was 2 1/2 dB worse than the Hustler set-up.

The Hustler with their kilowatt resonator was 1 dB worse than the Hustler standard resonator.

Eventually I re-wound the Hustler kilowatt resonator.  I space-wound the coil with solid magnet wire (~ #18 ?) instead of the original solidly-packed Litz wire.  Litz wire should not be used above 1 - 2 MHz.  The loss plummeted and so the feedpoint impedance dropped to 20 Ohms.  I needed to add a little fixed L-matching network to step 50 Ohms down to 20 Ohms.  The modified kilowatt Hustler coil is now my best 75 meter antenna.  The catch is that the operating bandwidth is now only about +/- 10 kHz.
The modified KW Hustler is now 2 1/2 dB better than the standard resonator, 5dB more gain than the Hamstick. 

Do you want bandwidth or gain?  The only way to get both is to have a screwdriver antenna. I haven't tested a screwdriver against the Hustler.

[W2JBL]

 i had excellent results with a hamstick on 40, bumper mounted to a Chevy Caprice, with an inductive matching transformer at the base. very good on 20 as well. all but useless on 75 though. with 25 watts on 40 AM i had a decent enough signal to cut it during the day. a bigger homebrew center loaded antenna with a nice high Q coil worked better, but was more trouble.  i liked the 40 meter hamstick because it did not look too "hamsexy".