On 7/4/2015 1:34 AM, John S wrote:
Okay. This data set is for a 43' carbon steel antenna on a perfect
ground fed with 25' of RG8A/U. No transformer.

I made a mistake. I used 3" copper pipe. I will re-do with 3" carbon
steel pipe.

No transformer:
Freq R X SWR
4.000 2.61 -12.68 20.382
5.000 20.92 20.65 2.867
6.000 28.18 -30.18 2.600
7.000 8.03 -5.57 6.304
8.000 5.70 12.35 9.317
9.000 6.11 30.75 11.314
10.000 9.00 56.13 12.662
11.000 20.37 105.05 13.626
12.000 139.02 278.20 14.204
13.000 125.69 -265.07 14.021
14.000 19.40 -94.97 12.182
15.000 11.41 -43.56 7.809
16.000 18.65 -11.02 2.830
17.000 56.19 -17.88 1.426
18.000 19.92 -31.06 3.599
19.000 9.26 -12.02 5.720
20.000 6.96 3.68 7.228
21.000 7.02 19.23 8.195
22.000 9.09 38.27 8.792
23.000 15.99 67.89 9.102
24.000 49.53 133.22 9.057
25.000 412.93 41.45 8.343
26.000 60.97 -117.33 6.399
27.000 29.70 -44.72 3.324
28.000 48.31 -10.74 1.247
29.000 60.26 -49.68 2.445
30.000 21.05 -40.86 4.142

1:4 transformer:
Freq R X SWR
4.000 4.21 19.69 13.745
5.000 26.48 74.45 6.450
6.000 149.09 -82.20 3.972
7.000 25.55 -37.90 3.288
8.000 15.45 -5.81 3.285
9.000 16.25 18.68 3.549
10.000 26.91 49.36 3.954
11.000 88.45 102.31 4.478
12.000 177.47 -114.21 5.105
13.000 28.81 -72.20 5.756
14.000 11.31 -30.71 6.152
15.000 8.73 -3.99 5.767
16.000 13.78 23.29 4.469
17.000 51.75 60.81 3.109
18.000 104.23 -32.25 2.336
19.000 36.12 -29.39 2.111
20.000 22.93 -5.09 2.210
21.000 22.96 16.44 2.467
22.000 34.32 42.05 2.819
23.000 86.65 73.65 3.255
24.000 162.78 -61.65 3.764
25.000 39.08 -69.10 4.270
26.000 15.65 -30.95 4.510
27.000 12.38 -4.51 4.075
28.000 19.52 20.93 3.075
29.000 56.33 42.38 2.197
30.000 83.40 -15.44 1.755

"John S" wrote in message ...

On 7/4/2015 1:34 AM, John S wrote:
Okay. This data set is for a 43' carbon steel antenna on a perfect
ground fed with 25' of RG8A/U. No transformer.

I made a mistake. I used 3" copper pipe. I will re-do with 3" carbon
steel pipe.

No transformer:
Freq R X SWR
4.000 2.61 -12.68 20.382
5.000 20.92 20.65 2.867
6.000 28.18 -30.18 2.600
7.000 8.03 -5.57 6.304
8.000 5.70 12.35 9.317
9.000 6.11 30.75 11.314
10.000 9.00 56.13 12.662
11.000 20.37 105.05 13.626
12.000 139.02 278.20 14.204
13.000 125.69 -265.07 14.021
14.000 19.40 -94.97 12.182
15.000 11.41 -43.56 7.809
16.000 18.65 -11.02 2.830
17.000 56.19 -17.88 1.426
18.000 19.92 -31.06 3.599
19.000 9.26 -12.02 5.720
20.000 6.96 3.68 7.228
21.000 7.02 19.23 8.195
22.000 9.09 38.27 8.792
23.000 15.99 67.89 9.102
24.000 49.53 133.22 9.057
25.000 412.93 41.45 8.343
26.000 60.97 -117.33 6.399
27.000 29.70 -44.72 3.324
28.000 48.31 -10.74 1.247
29.000 60.26 -49.68 2.445
30.000 21.05 -40.86 4.142

1:4 transformer:
Freq R X SWR
4.000 4.21 19.69 13.745
5.000 26.48 74.45 6.450
6.000 149.09 -82.20 3.972
7.000 25.55 -37.90 3.288
8.000 15.45 -5.81 3.285
9.000 16.25 18.68 3.549
10.000 26.91 49.36 3.954
11.000 88.45 102.31 4.478
12.000 177.47 -114.21 5.105
13.000 28.81 -72.20 5.756
14.000 11.31 -30.71 6.152
15.000 8.73 -3.99 5.767
16.000 13.78 23.29 4.469
17.000 51.75 60.81 3.109
18.000 104.23 -32.25 2.336
19.000 36.12 -29.39 2.111
20.000 22.93 -5.09 2.210
21.000 22.96 16.44 2.467
22.000 34.32 42.05 2.819
23.000 86.65 73.65 3.255
24.000 162.78 -61.65 3.764
25.000 39.08 -69.10 4.270
26.000 15.65 -30.95 4.510
27.000 12.38 -4.51 4.075
28.000 19.52 20.93 3.075
29.000 56.33 42.38 2.197
30.000 83.40 -15.44 1.755

Yes, very interesting. Throw in 75 feet of cable, and things get "better".

The lowest SWR is about 2:1 at 19 MHz.
It is about 6:1 on 20 meters.

On 7/4/2015 10:55 AM, Wayne wrote:


Yes, very interesting. Throw in 75 feet of cable, and things get "better".

The lowest SWR is about 2:1 at 19 MHz.
It is about 6:1 on 20 meters.



Of course. More loss in the cable makes it "better" (but, you know that).

On 7/4/2015 10:55 AM, Wayne wrote:


By the way, Wayne...

Are you aware of a companion Excel application for EZNEC called AutoEZ?
You can run many test cases in a few seconds using it. You can find it
on the EZNEC site.

It is how I generated the data I posted.

"John S" wrote in message ...

On 7/4/2015 10:55 AM, Wayne wrote:


By the way, Wayne...

Are you aware of a companion Excel application for EZNEC called AutoEZ?
You can run many test cases in a few seconds using it. You can find it
on the EZNEC site.

It is how I generated the data I posted.

Thanks, I'll look for that. I run the old wood burning version 3.0.

On 7/4/2015 12:32 PM, Wayne wrote:


"John S" wrote in message ...
On 7/4/2015 10:55 AM, Wayne wrote:


By the way, Wayne...

Are you aware of a companion Excel application for EZNEC called
AutoEZ? You can run many test cases in a few seconds using it. You can
find it on the EZNEC site.

It is how I generated the data I posted.

Thanks, I'll look for that. I run the old wood burning version 3.0.


BTW, Wayne, what are the dimensions of your metal roof? And how high?

"John S" wrote in message ...

On 7/4/2015 12:32 PM, Wayne wrote:


"John S" wrote in message ...
On 7/4/2015 10:55 AM, Wayne wrote:


By the way, Wayne...

Are you aware of a companion Excel application for EZNEC called
AutoEZ? You can run many test cases in a few seconds using it. You can
find it on the EZNEC site.

It is how I generated the data I posted.

Thanks, I'll look for that. I run the old wood burning version 3.0.


BTW, Wayne, what are the dimensions of your metal roof? And how high?

It's about 20 by 35 feet, 9 feet above ground. it's a big patio cover.

The underside is relatively smooth, but the top has all the ribbed sections.
Ribs are about 20 feet long and separated by about 2 feet.

Also on top are various runs of conduit and three large rectangular covers
for the underside lights.

I know this is TMI, but I'm just illustrating why I haven't tried to model
the entire metal roof....it's complicated

And I don't really need accurate patterns.