Frank,

A 'target' coil is 300mm x 300mm of 5/16 copper tubing. It is about 50 feet of
tubing, a .5 pitch, and should be close to 75 uH. This should be close. From
there simulation should show the best performance between varying the coils.

Thanks - Dan


Frank wrote:
Dan, I have been trying to replicate your inductors with NEC. It is a bit
tedious, just guessing wire gauge, coil diameter etc., to obtain the desired
inductance and Q. What are the physical dimensions of your inductors?

Have you had any luck with GH? You may have a problem with 4nec2 since you
must have a GM card along with the GH.

Frank


"dansawyeror" wrote in message
...

Good question. I will play with that. That said, based on Roy's comment at
minimum the load should appear nearly pure resistive.

I just tested the Autek with 6.25, 12.5, and 25 Ohm loads.
25 read 26
12.5 read 12 - 13 - 12 etc.
6.25 read mostly 7 with an occasional 6.

I would say for non-reactive loads it is pretty close.

Tomorrow - will be to experiment with non lumped inductors. That will be a
challenge.

Thanks - Dan


Frank wrote:

"dansawyeror" wrote in message
...


Frank,

The Autek is remarkably close. I have used it to checkout 50 and 25 Ohm
loads. For these two values it is very close. (It is battery level
sensitive.)

The couplers are a pair of M-C ZFDC 20-4's.

Dan


Thanks Dan, I had forgotten about Mini-Circuits. Their price is hard to
beat. I may pick up one of the "PDC" series dual directional couplers.
Incidentally your code indicates resonance occurs at 3.54 MHz. I wonder
how the Autek behaves when subjected to a reactive load does it actually
get close to the magnitude?

Frank