NM5K:
NO , I didn't see the pictures. Like I said, they didn't load on that
site. All the pix load except his.
Then you are missing a lot.
I don't know what the problem with eHam.net site is, I uploaded all the
pictures the same way, some showed, some not. This is why I posted link to my
page
http://www.k3bu.us/loadingcoils.htm
which has the pictures, also RIGHT drawings from ON4UN book, latest modeling of
W5DXP stub loaded G5RV and some selected comments explaining the phenomena.
Check it out.
Again, put on the fricken Hustler 80m resonator, feed it 100W and feel it!
No meters, no hokus pokus, just "naked" antenna.
What would that mean? The hustler coil is known to be flawed, and
makes a poor coil to be tested in this manner. The effects of it's
metal end caps, and overall design problems are fairly well known. I
refuse to use such a lousy coil. You can feed my homebrew coil 100w
all day long, and you won't feel anything except the finger on the
mike button hand start to go numb from holding the key down.
Another "very well known fact" from W8JI's teachings? Metal caps are at both
ends, top would feel the same then, it doesn't. Hustler coil is "lousy" because
uses aluminum wire to achieve "match" through some loss and that is additional
loss. But from the point of view as inductor, it is uniformly wound solenoid,
same wire and diameter, so according to I2R law, the heat developed in it is
proportional to the square of current. If there is more heat at the bottom,
then irrefutably there is more current flowing at the bottom.
Here is the shocker:
When W9UCW bunch was measuring various coils, they also compared that perfect
coil as you and I have (heavy wire, proper form factor, good connections) to
"lousy" Webster Banspanner sliding coil (aka cheap screwdriver) they found
negligible difference in measured signal strength. They rechecked everything
scratched their heads, but that was it. So another myth about the quality of
coil (resistance of course applies, but is minuscule) importance. Now when we
look at it from the point of view of effect of the coil on the efficiency of
antenna, it is explanatory. Coil replaces portion of radiator that is not there
anymore, so the significance of its quality is not as important as the position
of the coil on the radiator (area under current curve). Of course the ohmic
losses are a factor, but that is minuscule (ohms or two) versus reduction in
current flowing in remaining radiator. I like and have big fat coils, but looks
like they can be optimized better, perhaps heavier wire in first few turns,
slimmer construction, less wind load, but placed higher up on the mast. So
there is another one you don't have to believe, I sure was surprised.
Measure it!!!
Yep, it sure is. I sure as hell won't have anything shoved down my
throat. I'm sorry, but you all haven't convinced me yet that your
measurements are any more accurate than the one I quoted on that same
web page. And the one I quoted did give a fairly good description of
how he went about it. The guy I quoted said he saw constant current
across the coil. How do you explain that? Should I automatically
dismiss his findings just because you all have a web page and a bunch
of pictures? How do I know who did the more accurate test? I DON'T!!!
I am not a salesman, I will not try to convince you of anything. I can
elaborate and answer some questions and it is up to you to believe it or not.
You can believe engineers with education, their experience and results, or you
can believe some "technical impostor" as K7GCO phrased it.
You could see almost constant current across the coil if the coil is at the
base of quarter wave radiator, has heavy windings and is replacing relatively
short electrical length of the radiator. Did he mention what coil, where was
the coil placed? We have methods and pictures of W9UCW tests on various bands
at different positions, we have yet to get objections or pointed out errors in
his setup. We don't know much about the other one. W8JI said that he measured
thousands of loading coils, modeled them and found no difference. He is
obviously lying. He has yet to tell us about ONE measurement I asked him to do.
You believe what you want. As I mentioned we will write concise article on the
subject and you can take it from there or stick with Rauchians.
I sure enjoyed this exercise, learned from it a thing or two and I am looking
forward to implement some of the stuff (measure it too) in the design of new
loaded mobile and low band antennas. As they say on FreeRepublic.com, this is
series and hugh :-)
Yuri, K3BU