[Mobile-Portable] Mobile antenna tuner questions

[Art Clemons]

Melvyn Evans:
> In answer to your question, you would be better off
> buying used Hustler mobile antenna's, they work as
> well as any. It is essential that mobile antenna's are
> self resonant at the chosen frequency,using a
> stainless steel whip and a tuner would be an induced
> resonancy, and would be a very poor antenna on every
> band. Even the best mobile antenna's are so
> inefficient that a 100 watts from the rig means that
> on 20 metres only about 30 watts or less is being
> radiated, and on 80 metres it amounts to about 1 watt

First on 75 meters and 40 meters, a screwdriver radiates a great deal
more than the equivalent Hustlers on the respective bands.  2nd, the
operator apparently wanted an antenna that allowed changing frequency
without getting out of the vehicle, something that one Hustler
can't do.  While the Hustlers are center-loaded antennas, the predicted
Q of the individual coils on 40 and 75 is less if just because they're
closer wound and narrower.  On 75 meters according to W6AAQ, a
screwdriver is about 9% efficient compared to about one percent
efficiency for a base loaded whip or what W6AAQ calls a dummy load on a
stick, the Hustler close wound coils.

You might want to test this for your self, take some level of signal
like let's say 10 watts, feed it into a 75M Hustler, then feed the same
signal into a Screwdriver and use a Field Strength Meter out of the near
field to measure the strength (usually best done with another ham and an
attenuation box for repeatable measurements).

Finally I used to use Hustler Resonators, I still own the lightweight
40, 20 and 10M resonators.  I've actually performed the tests I suggest
with 75 and 40M resonators vs. a screwdriver and  a full size
bugcatcher.   There is a difference.  73 de n8blk/w3