"seediq" wrote in message
news
I do not doubt your information here. However, it seems to conflict with
my experiences working 75 meters. I work 75 each day using a 75 meter
horizontal loop. I hear the same characters on each day. Often a newbie
pops up with a poor signal. He is in the same area as "the gang" and yet
his signal stinks. Almost invariably we ask him about his G5RV. "Gee guys
how did you know I was using a G5RV?" Poor signals shows up every time. He
is using a dipole that is way too short to resonate on 75 meters. I think
they are 82 feet long. It seems to me if VSWR made little difference, then
his 82 foot long dipole on 75 meters should work just fine. Not trying for
a fight, just want an opinion about why we are hearing this effect. Of
course they are using tuners to make a match to their transceivers.


My own loop is carefully cut for 3.9 mhz. I need a tuner because it is
feed with 600 ohm open wire line and has a nasty VSWR because of mismatch
between the lead-in and antenna. The online calculator for loss using my
antenna system comes out to be 1/2 db. I can live with that. However, if I
put up a loop that was 1/2 the size I need, and then matched it with a
tuner, it would hardly work at all. I know. I tried loading mine on 160
meters. I could make a match with the tuner. But it was a bust.


You can not compair what goes on at 75 meters with 6 meters and above. Less
than 99.9 % of the hams can not put up equal antennas. For the mobile on
VHF it would have to be around 200 feet high and the truck would have ot be
200 to 400 feet wide and long..

I don't like the g5rv either, but they seem to work ok. Your loop works
fine for talking to the same people each day. Try it at other distances.
Going say 3000 miles away, a short vertical may be beter. I don't do much
on 75, but do some on 20 meters. It all depends on the propogation. One
day some stations with beams were hardly workable and a state or two away I
worked a mobile and another with a temporary vertical that was running 5
watts, they were both s9 or beter.

I have played with vhf repeaters for about 40 years. It may depend on the
area you are in as to the best kind of all around vhf antenna. One day a
fellow ham and I rounded up several antennas of all kinds. From 1/4 wave to
one about 6 feet long for 2 meters. There did not seem to be a clear
winner. Even a 40 meter antenna mounted to the bumper that was about 10
feet long worked as well receiving one repeater while the car was parked in
the same spot.
The area around here averages about 700 feet above sea level.

Some of the repeaters are from about the same height to around 5000 feet
above sea level. About the only overall differance we have found is the 5
or 6 foot long antennas do not seem to work very well while in motion and
the 5/8 antennas need to be stiff enough that they do not lay back at
highway speeds.

In areas that are flat it may be a whole differant story and the antennas
that keep the signal near the earth such as a 5/8 may work a lot beter
overall.

We did notice a big differance when going from a 4 bay dipole to a colinear
about the same overall length. The dipole and colinear were both Phelps
Dodge, not the cheap ham antennas. While the rated gain differance was
about 1 db infavor of the dipole aray, the noted coverage was much less when
using the colinear. Years later, we switched back to the dipole aray and
the coverage came back. If used in a differant area, there could be another
differance in coverage when compaired.