Re: Steve ugly-build LZ1AQ using MPS2222 sweeps uploaded to Photos
|
If anyone is interested I have a few unpopulated LZ1AQ boards, that take all leaded parts and 2N2222 transistors. If interested please contact me off list at everettsharp (at) aol com.
?
Everett N4CY
In a message dated 10/5/2024 11:07:25 AM Central Daylight Time, wassermanr46@... writes:
?
All,
?
The mentioned here Chavdar's webpage represents correct equivalent model of small loop antenna that should be used in order to come up with a dummy aerial for loop antenna.
?
Raphael
?
?
On Fri, Oct 4, 2024 at 11:25 PM, Mark Whittington AG5RT wrote:
The short circuit current (i.e. the Norton equivalent source current) is constant within 0.2 dB up to 30MHz.? This is much flatter than I would have expected.? I was equally surprised that the short circuit current at resonance was only 0.4dB higher than the value at low frequencies.?
Mark, I got the same sort of result....using either NEC4.2 or NEC5 engines....flat current vs. frequency response into a short-circuit.? On the other hand, with an open-circuit (i.e. 1 MEGohm) load, I got a rising 20dB/decade result that quite well matched the expected voltage up to about 1/2 the resonant frequency.? Above that the output voltage rises near resonance.? I'm reasonably confident that we are "driving" the simulation correctly.? See Chavdar's webpage: .... equation #2.
?
Dan - K3GMQ
?
|
F (MHz)
|
E_oc (formula)
|
E_oc(NEC)
|
|
0.01
|
0.000165
|
0.000164
|
|
0.03
|
0.000494
|
0.000491
|
|
0.1
|
0.001646
|
0.001638
|
|
0.3
|
0.004938
|
0.004913
|
|
1
|
0.01646
|
0.01638
|
|
3
|
0.049381
|
0.04934
|
|
10
|
0.164603
|
0.1719
|
|
15
|
0.246905
|
0.275
|
|
20
|
0.329206
|
0.4053
|
|
25
|
0.411508
|
0.5879
|
|
30
|
0.493809
|
0.8843
|
|
35
|
0.576111
|
1.496
|
|
40
|
0.658413
|
3.715
|
|
41
|
0.674873
|
5.13
|
|
42
|
0.691333
|
8.121
|
|
43
|
0.707794
|
17.04
|
|
44
|
0.724254
|
20.44
|
|
45
|
0.740714
|
9.267
|
|
46
|
0.757174
|
5.687
|
|
47
|
0.773635
|
4.082
|
|
Everett N4CY