On Mon, 24 Oct 2005 18:12:32 +0000 (UTC), "Reg Edwards"
wrote:
"Richard Clark" wrote -
Try googling the archives to see he does more than monitor.

Richard,
I'm a little surprised you have time to spy on my activities.

Hi Reggie,

There is no room for surprise and even less interest in your
"activities" whatever that term means. As for the time to accomplish
such a simple act - that is eclipsed in simply responding with these
first two sentences.

But your concern about Effective Series Resistance (ESR) of the tuning
capacitors in connection with VLF tuned loops is a bit overdone.

Clearly you in over your head, Old Son. I would suggest you exercise
your own skills in spying out common literature on the subject.

Remembering Lord Kelvin, let's crudely quantify things.

Sure, this exercise is going to floor you because you are clearly
quantifying only those things you are aware of. ESR is clearly beyond
your experience horizon given the howlers of dismissal you offer.

All we have to go on is Trabem's value of the tuning capacitor of 0.2
uF.

Therefore the size of his loop is a square of sides = 5 metres. Total
length of wire = 20 metres. Or somehing similar.

We have a loop so small, by your own reckoning, that its Radiation
Resistance amounts to barely 20 nanoOhms. This is not outside of the
realm of a simple reckoning - Lord Kelvinator would roll his eyes at
such omissions. The same efficiency issues that plague driving this
as a transmission antenna also plague it as a receiving antenna. I
see you neglect your own Kelvinator assessment of efficiency in your
cavalier dismissal.

Assume the wire diameter is a conservative thick 2mm.

In the face of a stated choice of:
I had a choice between large copper welding cable and
3 inch copper pipe. I chose the welding cable

Therefore we have L = 31 microHenrys, Reactance at 60 KHz = 12 ohms,
and RF resistance 0.23 ohms.

Adding loss seems to serve the argument rather than the plan.

From which the intrinsic Q of the loop inductance = 50.

Lord Kelvinator would throw his chalk at you for such reliance on what
is so easily measurable instead of being conjectured.

Assume the tuning capacitor is comprised of ten 0.02 uF capacitors in
parallel.

This is another failure that Lord Kelvinator would dope slap you with.
WHAT capacitors? What materials are being used, what vendor? what
specification? You are egregiously deficient in the particular of
MEASURABLES and you simply skip the SWAG. Is this the Kelvinator
ethic at work? This is lower 4th form effort. You are simply arguing
what you are familiar with and what follows reveals a vast
intellectual hole:
the ESR of a 0.02 uF capacitor, whatever it is, is
divided by 10. Yes, I know that the ESR of a capacitor at 60 KHz
involves a little more than lead resistance. But it's too small for an
American General Radio bridge to accurately measure it.

You clearly left the bench before the General Radio 1650-B became
commonly available to the calibration labs 40 years ago. There is
also the ESI Electro Scientific Inc. 250 DA Impedance Bridge. Both
bridges span 6 orders of magnitude for D measurement. We can presume
you have no experience with the Hewlett Packard HP 4270A either.

Going further (and certainly more modern) we have the ANDEEN-HAGERLING
AH 2700A which offers loss down to a dissipation factor of 1.5x10-8
tan d. This, by the way, does not extend above 20KHz but certainly
blows away any argument of anything being too small for its 12 ORDERS
of magnitude to encompass.

I could offer more examples, but that would be like shooting fish in a
barrel.

Reggie, you are simply gusting on with confirmed bafflegab:
Its all guesswork of course.

Incidentally, if Trabem obtains batchea of nominally identical value
capacitors, he will probably find they are all on the same side of the
tolerance.
Let's see, I said that already and you parrot it either
1. without attribution (plagiarizing);
2. responding without reading;
3. both.

73's
Richard Clark, KB7QHC