"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

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

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

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

"dansawyeror" wrote in message
...
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

Having trouble producing a good model Dan. NEC 2 indicates Qs which are
5000, but no warnings or errors. I can run it in NEC 4.1, single, and
double precision, but I get over 400 warnings in the NEC output file; such
as:

SEGCHK: WARNING - SEGMENTS 1 AND 271 CROSS AT A MIDPOINT WITH SEPARATION
LESS THAN THE SUM OF THEIR RADII

SEGCHK: WARNING - THE CENTER OF SEGMENT 1 IS WITHIN THE VOLUME OF SEGMENT
271

These warnings are particularly strange since, for example, absolute
segments 1 and 271 are almost 12" apart in the model. Will see what I can
do to correct the error.

73,

Frank

The code I am using is as follows:

CM Inductor Q Calculation
CE
GH 1 300 1 12 6 6 6 6 0.3125
GW 2 5 6 0 12 0 0 12 0.3125
GW 3 10 0 0 12 0 0 0 0.3125
GW 4 5 0 0 0 6 0 0 0.3125
GS 0 0 0.025400
GE 0
EX 0 3 5 00 1 0
FR 0 5 0 0 3.7 0.02
LD 5 1 1 320 5.7001E7
RP 0 181 1 1000 -90 90 1.00000 1.00000
EN

Frank wrote:
"dansawyeror" wrote in message
...
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

Having trouble producing a good model Dan. NEC 2 indicates Qs which are
5000, but no warnings or errors. I can run it in NEC 4.1, single, and
double precision, but I get over 400 warnings in the NEC output file; such
as:

SEGCHK: WARNING - SEGMENTS 1 AND 271 CROSS AT A MIDPOINT WITH SEPARATION
LESS THAN THE SUM OF THEIR RADII

SEGCHK: WARNING - THE CENTER OF SEGMENT 1 IS WITHIN THE VOLUME OF SEGMENT
271

These warnings are particularly strange since, for example, absolute
segments 1 and 271 are almost 12" apart in the model. Will see what I can
do to correct the error.

73,

Frank

The code I am using is as follows:

CM Inductor Q Calculation
CE
GH 1 300 1 12 6 6 6 6 0.3125
GW 2 5 6 0 12 0 0 12 0.3125
GW 3 10 0 0 12 0 0 0 0.3125
GW 4 5 0 0 0 6 0 0 0.3125
GS 0 0 0.025400
GE 0
EX 0 3 5 00 1 0
FR 0 5 0 0 3.7 0.02
LD 5 1 1 320 5.7001E7
RP 0 181 1 1000 -90 90 1.00000 1.00000
EN

NEC-2 and NEC-4 have different formats for the GH 'card'. This is the
NEC-2 format, which will be interpreted differently by NEC-4. See your
NEC-4 documentation for the correct NEC-4 format.

Roy Lewallen, W7EL

NEC-2 and NEC-4 have different formats for the GH 'card'. This is the
NEC-2 format, which will be interpreted differently by NEC-4. See your
NEC-4 documentation for the correct NEC-4 format.

Roy Lewallen, W7EL

Thanks Roy, now you mention it I do remember that there are some
differences. Should have checked with my manual before running it instead
of just cutting and pasting NEC 2 code. Made the appropriate correction and
it is now working with a reasonable correlation with NEC 2. Heck, now I
just noticed I had entered the wire diameter instead of its radius!

Frank, VE6CB