RadioBanter - View Single Post - Current in antenna loading coils controversy

November 2nd 03, 03:11 AM

oSaddam (Yuri Blanarovich) wrote in message ...
But....Just using my built in
"BS" filter only, which rarely seems to fails me, and ignoring all
other influences, I still have to side with Tom. I still think the
current is fairly constant.

Nothing
personal either way...But I have learned never to ignore my BS filter,
so I'm going with it. MK

Same here,
did your filter filtered out W5DXP pudding? The "theoretical" proof is right
there. Or are you drinking the same coolaide as Tom? :-)

Yuri

Reality vs. Speculations? Duuuh?

I found this comment interesting. Note this is from one that actually
has tried measuring the current in coils. This was from the site you
mention...

quote
I once had an occasion where the bottom of a coil did get warm, while
the top did not. Yet my RF ammeters showed the same current on both
ends. What was going on?

I ultimately determined that the soldered connection from the coil to
the lower antenna mast (for experimentation, it was copper) was adding
some undesireable resistance. Solder is not a particularly good
conductor of electricity. I copper-plated over the solder joint. Not
only did the bottom section of the coil no longer get warm, but the
two RF ammeters both showed about 20% more current flowing in the
antenna. And my far-field instruments showed a 1.5dB increase in field
strength.

unquote

This is one example of being fooled....If you took coil temp at face
value, you would think the current taper was quite steep, judging from
the temp's of the windings. But nope...A resistive connection seemed
to be the culprit. Note that his meters showed the same current on
both ends. :/ You can see why I'm afraid of that "hook" that usually
is lurking ready to bite at a moments notice.
Don't worry, if you are right, it will come out in the end. But that
hook...Ouch.. MK