On Thursday, June 27, 2013 1:34:20 PM UTC-5, seediq wrote:


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.

A high SWR on it's own is not always bad news. It depends
on the feed line used, freq, etc.
The main reason the G5RV's don't do so hot is the goofy
method of feeding most seem to use. IE: a length of twin lead
to a choke, to coax. And then some add insult to injury and
run a tuner at the shack. A good amount of power is turned to
heat. But if you feed the same antenna with ladder line the
whole route, the losses are not so bad, even with a high SWR.
If you tune the line and use no tuner, fairly low losses.
If you use a tuner, not quite as good, but not too bad if you
use the least amount of inductance needed to get a usable match.
All antennas will radiate nearly all power applied to them.
The trick is getting it from the rig to the antenna without
turning some into heat. This is where the usual G5RV is failing.
Some of the power is not making it to the antenna due to obtuse
lossy methods of feeding. Same issue with some of the windoms, etc
that are sold.