RadioBanter - View Single Post

February 9th 04, 06:41 AM

oUsama (Yuri Blanarovich) wrote in message
So now it's 0.51% efficient instead of only 0.49% right? [g]

Nope, more like going from not getting answers to my calls or CQ (S0 or less
:-) to getting reports from W6, through P4 to Eu of S6 to S9. Even getting hell
from W8JI for wiping out - QRMing the DX window.

The noise has been fairly low lately. How was the noise with the old
version? How long ago was that?
An A/B test would be needed to form an accurate conclusion. But I
don't doubt you saw an improvement if you raised the coil or added a
hat...

You learned heads figure out the efficiency improvement in dBm, uV or dB or S
units. It may not jive with your decimal points, but is OK with me.

In the past Cecil showed some results from mobile antenna shootouts, where
simple change in position of the loading coil can mean dBs or tens of dBs
difference. Might not be reflected in your modeling results, but reality
speaks. Those who built and used the stuff know it. Those who calculate it
"know better"?

But! What does this have to do with the "current taper" debate? All
you are doing is applying practices that have been in use for years. I
was doing what you are doing about 14 years ago when I first got a
mobile radio. I've been using lower "add on " masts to boost coil
position since nearly day one. It was common knowledge even back then.
It doesn't really matter what the taper is across the coil, you still
are probably trying to get it as high as you can before coil losses
get too severe, and use as much top hat as you can. "If you use a
hat". I think appx 75% up is about as high as you would ever want to
go with a coil. You can use Reg's vertload and find the best position
to a degree of accuracy that would never be noticed on the air. 50% up
is very close behind in performance. Mine is 55% up " 10 ft center
load" when driving, and about 64% when parked and using the extra 3 ft
mast at the bottom. "13 ft with coil about 8.5 feet up". Sure, I could
jump it up to 70-75% , but it's not worth the hassle of whacking the
coil on every tree I pass. My coil is over 9 ft off the ground even in
the shorter 10 ft driving mode. Add three to that when parked.
I fully agree with elevating the coil position of short low band
verticals, but this is ancient news. What does the current taper, or
you knowing about it or measuring it, do to further improve the
antenna over what it would be anyway? It wouldn't effect me. I've
already got mine as high as I can get it without a major mast
overhaul.

This is getting amusing and eye opening how many flat earth society members are
out there. Keep on harping!

I'd rather be a flat earther than have delusions of a small current
taper across a loading coil really amounting to anything important,
other than maybe settling a ****ing match with Tom. :/ It's not going
to change a thing in the real world because the optimum coil positions
are already known, and have been real world tested with FS tests.
Taper, or no taper. Just because you declare we have current taper
across the coil, does not mean anything is going to suddenly change.
It's just something to think about.
It's like worrying about the current taper on a dipole. Knowing about
it doesn't mean you can really do anything to further improve the
antenna. Some say CCD antennas are better, but I'm not convinced after
listening to quite a few over the years. I usually had a better
overall signal with my old fashioned "flat earth" coax fed dipoles,
than they did with their "new fangled" CCD antennas. Coil placement
can effect loaded dipoles and yagi's, but again, ancient news.
But anyway, glad to hear you are finally getting around to applying
these old commonly used practices to improve your antenna.
They haven't kept you locked away in a closet the past few years have
they? I keep getting visions of mushrooms... :/ MK