Area 51 for Antenna Modelers & Builders (See Post #1)

423516 Views 1327 Replies 63 Participants Last post by majortom, Jun 20, 2020

stampeder

Discussion Starter · Apr 21, 2009 (Edited)

This thread has been created strictly for Antenna Modelers and Builders who like to live not just on the leading edge but on the bleeding edge of antenna research and development.

Area 51 is for posting and discussion of any computer model of any experimental antenna by Antenna Modelers and Builders

Area 51 is not for casual builders or newcomers to ask questions or look for useable home antennas. Participants here are expected to fairly well "know their stuff".

If an antenna design is shown to be worthwhile for general public consumption we will move it out of Area 51 into the main Antenna Research & Development Forum.

Just remember what the ancient map makers wrote when they had no further info to illustrate: "Beyond here be dragons!"

281 - 300 of 1328 Posts

300ohm

· #281 · Aug 19, 2009

Heh, drawing them can be tricky at times. Also, turn off (uncheck)"Keep Connected" when adding the lines. Practice makes perfect, heh.
What channel range do you want to optimize for ? In other words, YOUR situation youre looking to achieve.

300ohm

· #282 · Aug 19, 2009

If someone would help me to make sense out this beast and analyze it, I would be very thankful.

Rather than constantly building in the dark, (like we all used to do in the old days, heh) try computer modeling yourself. Its not really all that hard, but does have a little learning curve, which comes if you have some patience.
A good start would be the directions in this thread here : http://www.digitalhome.ca/forum/showthread.php?t=107457
Once you get comfortable with looking at antenna computer models, then its just a short jump to the computer modeling thread here :
http://www.digitalhome.ca/forum/showthread.php?t=83772

wildwillie

· #283 · Aug 19, 2009

300ohms I'm doing this so the southwestern end of ontario 50 miles away from windsor can have a nice GH and maybe others across the way . Its almost Hockey Time on CBC

Oh hey 300ohms and Xauto well boys here she is , no not the DBGH but 11.54 dbi raw at channel 7
Now if I can figuer out the lines 14dbi on channel 7

She looks like stampeder's little space ship lmao

Code:

CM X0256 with UHF Collinear Rods
CM design by WildWillie
CM VHF-HI ONLY Collinear Rods
CM SWR below <3
CM 7	174
CM 8	180
CM 9	186
CM 10	192
CM 11	198
CM 12	204
CM 13	210
CE
GW	1	3	0	-2.5	0	0	1.90944882	0	0.075
GW	2	7	0	1.90944882	0	0	7.42125984	5.51181102	0.13779528
GW	3	7	0	7.42125984	5.51181102	0	1.90944882	11.023622	0.13779528
GW	4	7	0	1.90944882	11.023622	0	7.42125984	16.5354331	0.13779528
GW	5	3	0	7.42125984	16.5354331	0	12.1338598	16.5354331	0.13779528
GW	6	7	0	1.90944882	0	0	7.42125984	-5.511811	0.13779528
GW	7	7	0	7.42125984	-5.511811	0	1.90944882	-11.023622	0.13779528
GW	8	7	0	1.90944882	-11.023622	0	7.42125984	-16.535433	0.13779528
GW	9	3	0	7.42125984	-16.535433	0	12.1338598	-16.535433	0.13779528
GW	10	7	0	-2.5	0	0	-8.011811	5.51181102	0.13779528
GW	11	7	0	-8.011811	5.51181102	0	-2.5	11.023622	0.13779528
GW	12	7	0	-2.5	11.023622	0	-8.011811	16.5354331	0.13779528
GW	13	3	0	-8.011811	16.5354331	0	-12.724411	16.5354331	0.13779528
GW	14	7	0	-2.5	0	0	-8.011811	-5.511811	0.13779528
GW	15	7	0	-8.011811	-5.511811	0	-2.488189	-10.988189	0.13779528
GW	16	7	0	-2.488189	-10.988189	0	-8	-16.5	0.13779528
GW	17	3	0	-8	-16.5	0	-12.7	-16.5	0.13779528
GW	117	7	0	-0.25	-19	0	-9.75	-19	0.13779528
GW	118	1	0	-9.75	-19	0	-10	-18.75	0.13779528
GW	119	1	0	-10	-18.75	0	-10	-18.25	0.13779528
GW	120	1	0	-10	-18.25	0	-9.75	-18	0.13779528
GW	121	1	0	-9.75	-18	0	-8.25	-18	0.13779528
GW	122	1	0	-8.25	-18	0	-8	-17.75	0.13779528
GW	123	1	0	-8	-17.75	0	-8	-17.25	0.13779528
GW	124	1	0	-8	-17.25	0	-8.25	-17	0.13779528
GW	125	3	0	-8.25	-17	0	-12.4	-17	0.13779528
GW	126	7	0	-0.25	-19	0	9.25	-19	0.13779528
GW	127	1	0	9.25	-19	0	9.5	-18.75	0.13779528
GW	128	1	0	9.5	-18.75	0	9.5	-18.25	0.13779528
GW	129	1	0	9.5	-18.25	0	9.25	-18	0.13779528
GW	130	1	0	9.25	-18	0	7.75	-18	0.13779528
GW	131	1	0	7.75	-18	0	7.5	-17.75	0.13779528
GW	132	1	0	7.5	-17.75	0	7.5	-17.25	0.13779528
GW	133	1	0	7.5	-17.25	0	7.75	-17	0.13779528
GW	134	3	0	7.75	-17	0	11.9	-17	0.13779528
GW	135	7	0	-0.25	19.2	0	9.25	19.2	0.13779528
GW	136	1	0	9.25	19.2	0	9.5	18.95	0.13779528
GW	137	1	0	9.5	18.95	0	9.5	18.45	0.13779528
GW	138	1	0	9.5	18.45	0	9.25	18.2	0.13779528
GW	139	1	0	9.25	18.2	0	7.75	18.2	0.13779528
GW	140	1	0	7.75	18.2	0	7.5	17.95	0.13779528
GW	141	1	0	7.5	17.95	0	7.5	17.45	0.13779528
GW	142	1	0	7.5	17.45	0	7.75	17.2	0.13779528
GW	143	3	0	11.9	17.2	0	7.75	17.2	0.13779528
GW	144	7	0	-0.25	19.2	0	-9.75	19.2	0.13779528
GW	145	1	0	-9.75	19.2	0	-10	18.95	0.13779528
GW	146	1	0	-10	18.95	0	-10	18.45	0.13779528
GW	147	1	0	-10	18.45	0	-9.75	18.2	0.13779528
GW	148	1	0	-9.75	18.2	0	-8.25	18.2	0.13779528
GW	149	1	0	-8.25	18.2	0	-8	17.95	0.13779528
GW	150	1	0	-8	17.95	0	-8	17.45	0.13779528
GW	151	1	0	-8	17.45	0	-8.25	17.2	0.13779528
GW	152	3	0	-8.25	17.2	0	-12.4	17.2	0.13779528
GW	174	23	-9.5	-14	0	-9.5	15.5	0	0.13779528
GW	175	23	-9.5	-14	-7.2	-9.5	15.5	-7.2	0.13779528
GW	176	23	-9.5	-36.1	3	-9.5	-4.6	3	0.13779528
GW	177	23	-9.5	4	3	-9.5	35.5	3	0.13779528
GW	178	23	-9.5	-36.2	-3	-9.5	-4.7	-3	0.13779528
GW	179	23	-9.5	4	-3	-9.5	35.5	-3	0.13779528
GW	180	23	-9.5	-36.8	6	-9.5	-6.8	6	0.13779528
GW	181	23	-9.5	-36.9	-6	-9.5	-6.9	-6	0.13779528
GW	182	23	-9.5	6.3	-6	-9.5	36.3	-6	0.13779528
GW	183	23	-9.5	6.1	6	-9.5	36.1	6	0.13779528
GW	184	23	-9.5	-14.6	7.2	-9.5	14.9	7.2	0.13779528
GW	187	23	-9.5	-15	-29	-9.5	16.95	-29	0.13779528
GW	188	23	-9.5	-15.95	29	-9.5	16	29	0.13779528
GW	189	9	-4	12.5	2	-4	0.5	2	0.13779528
GW	190	9	-4	-0.5	2	-4	-12.5	2	0.13779528
GW	191	9	-4	12.5	-2	-4	0.5	-2	0.13779528
GW	192	9	-4	-0.5	-2	-4	-12.5	-2	0.13779528
GW	193	9	-4	12.5	11	-4	0.5	11	0.13779528
GW	194	9	-4	-0.5	11	-4	-12.5	11	0.13779528
GW	195	9	-4	12.5	8	-4	0.5	8	0.13779528
GW	196	9	-4	-0.5	8	-4	-12.5	8	0.13779528
GW	197	9	-4	12.5	-8	-4	0.5	-8	0.13779528
GW	198	9	-4	-0.5	-8	-4	-12.5	-8	0.13779528
GW	199	9	-4	12.5	-11	-4	0.5	-11	0.13779528
GW	200	9	-4	-0.5	-11	-4	-12.5	-11	0.13779528
GW	201	9	-4	12.5	24	-4	0.5	24	0.13779528
GW	202	9	-4	-0.5	24	-4	-12.5	24	0.13779528
GW	203	9	-4	12.5	5	-4	0.5	5	0.13779528
GW	204	9	-4	-0.5	5	-4	-12.5	5	0.13779528
GW	205	9	-4	12.5	-5	-4	0.5	-5	0.13779528
GW	206	9	-4	-0.5	-5	-4	-12.5	-5	0.13779528
GW	207	9	-4	13	-24	-4	1	-24	0.13779528
GW	208	9	-4	-0.5	-24	-4	-12.5	-24	0.13779528
GW	209	19	-9.5	-26.5	27	-9.5	-1	27	0.13779528
GW	210	19	-9.5	1	27	-9.5	26.5	27	0.13779528
GW	211	19	-9.5	-26.5	-27	-9.5	-1	-27	0.13779528
GW	212	19	-9.5	1	-27	-9.5	26.5	-27	0.13779528
GW	213	23	-9.5	-16	25	-9.5	15.95	25	0.13779528
GW	214	19	-9.5	-26.55	23	-9.5	-1.05	23	0.13779528
GW	215	19	-9.5	0.95	23	-9.5	26.45	23	0.13779528
GW	216	23	-9.5	-15	-25	-9.5	16.95	-25	0.13779528
GW	217	19	-9.5	-26.5	-23	-9.5	-1	-23	0.13779528
GW	218	19	-9.5	1	-23	-9.5	26.5	-23	0.13779528
GS	0	0	0.0254		' All in in.
GE	0
EK
LD	5	0	0	0	2.49e7	0
EX	0	1	2	0	1	0
GN	-1
FR	0	1	0	0	173	0
RP 0 1 73 1510 90 0 1 5 0 0

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300ohm

· #284 · Aug 19, 2009

no not the DBGH but 11.54 dbi raw at channel 7

So channel 7 is what your after, 174 - 180 mhz, middle at 177 mhz.
On the above nec file at 177 mhz, I get 9.92 dbi Raw Gain minus the .12 dbi AGT adjustment, equals 9.80 dbi Raw Gain. Net Gain with the SWR at 1.83 requires about a .40 dbi adjustment for a Net Gain of about 9.4 dbi.

wildwillie

· #285 · Aug 19, 2009

hmmmmm I'm getting a SWR of 1.24 and a gain of 11 dbi , I must be doing something wrong again.

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300ohm

· #286 · Aug 19, 2009

I must be doing something wrong again.

Nope, I had the wrong file loaded in for the calculation, heh. Sorry about that.

OK, so its 11.2 minus the .45 AGT adjustment equals 10.75 dbi Raw Gain. Take about .1 off for 1.2 SWR equals 10.65 dbi Net Gain at 177 mhz.

bokakob

· #287 · Aug 19, 2009

Thanks much -- will try!

300ohm

· #288 · Aug 19, 2009

Keep in mind, a vast majority of the options and features in 4nec2 deal with transmitting antennas, so dont be intimidated by all the extraneous clap trap. For receiving antennas we commonly use, its mostly just a few options we use, over and over and over again, heh.

Xauto

· #289 · Aug 20, 2009

bokakob:Your 8 diamonds is good for Ch.20 to 51. Raw gain of 8 with a peak at [email protected] and back to 8 at Ch.51

300ohm

· #290 · Aug 20, 2009

Wildwillie, the easiest way to draw the phasing lines, is to (after duplicating the SBGH and centering them so the new DBGH source wire will be on 0 on the Y axis) :

1) In Geometry Edit YZ view, draw the phasing lines and the source wire outside of the antenna, in the place where they would go if they were moved over. Highlight those wires for movement.
2) Switch to XY view, and move the whole phasing line group to the center of the antenna, at a distance in front of the antenna (usually an inch).
3) Switch to 3D view, tilt the antenna around and scale it so its a comfortable drawing distance/size, and connect the antenna to the phasing lines.

Xauto, good job on the general purpose top hat NAROD. It really starts to drop off after channel 13.

300ohm

· #291 · Aug 20, 2009

It looks like the optimum spacing between the bays for channel 7, to get that full 2.5 to 3 dbi additional gain, is going to be a huge distance, heh. So, I just went for something reasonable.

Unoptimized X271 Double Bay version NEC file:

Code:

CM X0256 with UHF Collinear Rods
CM Unoptimized Double Bay Version by 300ohm
CM design by WildWillie
CM VHF-HI ONLY Collinear Rods
CM SWR below <3
CM 7	174
CM 8	180
CM 9	186
CM 10	192
CM 11	198
CM 12	204
CM 13	210
CE
GW	2	7	0	2.20475	-30	0	7.71656102	-24.488189	0.13779528
GW	3	7	0	7.71656102	-24.488189	0	2.20475	-18.976378	0.13779528
GW	4	7	0	2.20475	-18.976378	0	7.71656102	-13.464567	0.13779528
GW	5	3	0	7.71656102	-13.464567	0	12.429161	-13.464567	0.13779528
GW	6	7	0	2.20475	-30	0	7.71656102	-35.511811	0.13779528
GW	7	7	0	7.71656102	-35.511811	0	2.20475	-41.023622	0.13779528
GW	8	7	0	2.20475	-41.023622	0	7.71656102	-46.535433	0.13779528
GW	9	3	0	7.71656102	-46.535433	0	12.429161	-46.535433	0.13779528
GW	10	7	0	-2.2046988	-30	0	-7.7165098	-24.488189	0.13779528
GW	11	7	0	-7.7165098	-24.488189	0	-2.2046988	-18.976378	0.13779528
GW	12	7	0	-2.2046988	-18.976378	0	-7.7165098	-13.464567	0.13779528
GW	13	3	0	-7.7165098	-13.464567	0	-12.42911	-13.464567	0.13779528
GW	14	7	0	-2.2046988	-30	0	-7.7165098	-35.511811	0.13779528
GW	15	7	0	-7.7165098	-35.511811	0	-2.1928878	-40.988189	0.13779528
GW	16	7	0	-2.1928878	-40.988189	0	-7.7046988	-46.5	0.13779528
GW	17	3	0	-7.7046988	-46.5	0	-12.404699	-46.5	0.13779528
GW	117	7	0	0	-49.2	0	-9.5	-49.2	0.13779528
GW	118	1	0	-9.5	-49.2	0	-9.75	-48.95	0.13779528
GW	119	1	0	-9.75	-48.95	0	-9.75	-48.45	0.13779528
GW	120	1	0	-9.75	-48.45	0	-9.5	-48.2	0.13779528
GW	121	1	0	-9.5	-48.2	0	-8	-48.2	0.13779528
GW	122	1	0	-8	-48.2	0	-7.75	-47.95	0.13779528
GW	123	1	0	-7.75	-47.95	0	-7.75	-47.45	0.13779528
GW	124	1	0	-7.75	-47.45	0	-8	-47.2	0.13779528
GW	125	3	0	-8	-47.2	0	-12.15	-47.2	0.13779528
GW	126	7	0	0	-49.2	0	9.5	-49.2	0.13779528
GW	127	1	0	9.5	-49.2	0	9.75	-48.95	0.13779528
GW	128	1	0	9.75	-48.95	0	9.75	-48.45	0.13779528
GW	129	1	0	9.75	-48.45	0	9.5	-48.2	0.13779528
GW	130	1	0	9.5	-48.2	0	8	-48.2	0.13779528
GW	131	1	0	8	-48.2	0	7.75	-47.95	0.13779528
GW	132	1	0	7.75	-47.95	0	7.75	-47.45	0.13779528
GW	133	1	0	7.75	-47.45	0	8	-47.2	0.13779528
GW	134	3	0	8	-47.2	0	12.15	-47.2	0.13779528
GW	135	7	0	0	-10.8	0	9.5	-10.8	0.13779528
GW	136	1	0	9.5	-10.8	0	9.75	-11.05	0.13779528
GW	137	1	0	9.75	-11.05	0	9.75	-11.55	0.13779528
GW	138	1	0	9.75	-11.55	0	9.5	-11.8	0.13779528
GW	139	1	0	9.5	-11.8	0	8	-11.8	0.13779528
GW	140	1	0	8	-11.8	0	7.75	-12.05	0.13779528
GW	141	1	0	7.75	-12.05	0	7.75	-12.55	0.13779528
GW	142	1	0	7.75	-12.55	0	8	-12.8	0.13779528
GW	143	3	0	12.15	-12.8	0	8	-12.8	0.13779528
GW	144	7	0	0	-10.8	0	-9.5	-10.8	0.13779528
GW	145	1	0	-9.5	-10.8	0	-9.75	-11.05	0.13779528
GW	146	1	0	-9.75	-11.05	0	-9.75	-11.55	0.13779528
GW	147	1	0	-9.75	-11.55	0	-9.5	-11.8	0.13779528
GW	148	1	0	-9.5	-11.8	0	-8	-11.8	0.13779528
GW	149	1	0	-8	-11.8	0	-7.75	-12.05	0.13779528
GW	150	1	0	-7.75	-12.05	0	-7.75	-12.55	0.13779528
GW	151	1	0	-7.75	-12.55	0	-8	-12.8	0.13779528
GW	152	3	0	-8	-12.8	0	-12.15	-12.8	0.13779528
GW	174	23	-9.5	-14	-30	-9.5	15.5	-30	0.13779528
GW	175	23	-9.5	-14	-37.2	-9.5	15.5	-37.2	0.13779528
GW	176	23	-9.5	-36.1	-27	-9.5	-4.6	-27	0.13779528
GW	177	23	-9.5	4	-27	-9.5	35.5	-27	0.13779528
GW	178	23	-9.5	-36.2	-33	-9.5	-4.7	-33	0.13779528
GW	179	23	-9.5	4	-33	-9.5	35.5	-33	0.13779528
GW	180	23	-9.5	-36.8	-24	-9.5	-6.8	-24	0.13779528
GW	181	23	-9.5	-36.9	-36	-9.5	-6.9	-36	0.13779528
GW	182	23	-9.5	6.3	-36	-9.5	36.3	-36	0.13779528
GW	183	23	-9.5	6.1	-24	-9.5	36.1	-24	0.13779528
GW	184	23	-9.5	-14.6	-22.8	-9.5	14.9	-22.8	0.13779528
GW	187	25	-9.5	-16	-59	-9.5	16	-59	0.13779528
GW	188	25	-9.5	-16	-1	-9.5	16	-1	0.13779528
GW	189	9	-4	12.5	-28	-4	0.5	-28	0.13779528
GW	190	9	-4	-0.5	-28	-4	-12.5	-28	0.13779528
GW	191	9	-4	12.5	-32	-4	0.5	-32	0.13779528
GW	192	9	-4	-0.5	-32	-4	-12.5	-32	0.13779528
GW	193	9	-4	12.5	-19	-4	0.5	-19	0.13779528
GW	194	9	-4	-0.5	-19	-4	-12.5	-19	0.13779528
GW	195	9	-4	12.5	-22	-4	0.5	-22	0.13779528
GW	196	9	-4	-0.5	-22	-4	-12.5	-22	0.13779528
GW	197	9	-4	12.5	-38	-4	0.5	-38	0.13779528
GW	198	9	-4	-0.5	-38	-4	-12.5	-38	0.13779528
GW	199	9	-4	12.5	-41	-4	0.5	-41	0.13779528
GW	200	9	-4	-0.5	-41	-4	-12.5	-41	0.13779528
GW	201	9	-4	12.5	-6	-4	0.5	-6	0.13779528
GW	202	9	-4	-0.5	-6	-4	-12.5	-6	0.13779528
GW	203	9	-4	12.5	-25	-4	0.5	-25	0.13779528
GW	204	9	-4	-0.5	-25	-4	-12.5	-25	0.13779528
GW	205	9	-4	12.5	-35	-4	0.5	-35	0.13779528
GW	206	9	-4	-0.5	-35	-4	-12.5	-35	0.13779528
GW	207	9	-4	12.5	-54	-4	0.5	-54	0.13779528
GW	208	9	-4	-0.5	-54	-4	-12.5	-54	0.13779528
GW	209	19	-9.5	-26.5	-3	-9.5	-1	-3	0.13779528
GW	210	19	-9.5	1	-3	-9.5	26.5	-3	0.13779528
GW	211	19	-9.5	-26.5	-57	-9.5	-1	-57	0.13779528
GW	212	19	-9.5	1	-57	-9.5	26.5	-57	0.13779528
GW	213	25	-9.5	-16	-5	-9.5	16	-5	0.13779528
GW	214	19	-9.5	-26.5	-7	-9.5	-1	-7	0.13779528
GW	215	19	-9.5	1	-7	-9.5	26.5	-7	0.13779528
GW	216	25	-9.5	-16	-55	-9.5	16	-55	0.13779528
GW	217	19	-9.5	-26.5	-53	-9.5	-1	-53	0.13779528
GW	218	19	-9.5	1	-53	-9.5	26.5	-53	0.13779528
GW	220	7	0	2.20475	30	0	7.71656102	35.511811	0.13779528
GW	221	7	0	7.71656102	35.511811	0	2.20475	41.023622	0.13779528
GW	222	7	0	2.20475	41.023622	0	7.71656102	46.5354331	0.13779528
GW	223	3	0	7.71656102	46.5354331	0	12.429161	46.5354331	0.13779528
GW	224	7	0	2.20475	30	0	7.71656102	24.488189	0.13779528
GW	225	7	0	7.71656102	24.488189	0	2.20475	18.976378	0.13779528
GW	226	7	0	2.20475	18.976378	0	7.71656102	13.464567	0.13779528
GW	227	3	0	7.71656102	13.464567	0	12.429161	13.464567	0.13779528
GW	228	7	0	-2.2046988	30	0	-7.7165098	35.511811	0.13779528
GW	229	7	0	-7.7165098	35.511811	0	-2.2046988	41.023622	0.13779528
GW	230	7	0	-2.2046988	41.023622	0	-7.7165098	46.5354331	0.13779528
GW	231	3	0	-7.7165098	46.5354331	0	-12.42911	46.5354331	0.13779528
GW	232	7	0	-2.2046988	30	0	-7.7165098	24.488189	0.13779528
GW	233	7	0	-7.7165098	24.488189	0	-2.1928878	19.011811	0.13779528
GW	234	7	0	-2.1928878	19.011811	0	-7.7046988	13.5	0.13779528
GW	235	3	0	-7.7046988	13.5	0	-12.404699	13.5	0.13779528
GW	236	7	0	-4.371e-15	10.8	0	-9.5	10.8	0.13779528
GW	237	1	0	-9.5	10.8	0	-9.75	11.05	0.13779528
GW	238	1	0	-9.75	11.05	0	-9.75	11.55	0.13779528
GW	239	1	0	-9.75	11.55	0	-9.5	11.8	0.13779528
GW	240	1	0	-9.5	11.8	0	-8	11.8	0.13779528
GW	241	1	0	-8	11.8	0	-7.75	12.05	0.13779528
GW	242	1	0	-7.75	12.05	0	-7.75	12.55	0.13779528
GW	243	1	0	-7.75	12.55	0	-8	12.8	0.13779528
GW	244	3	0	-8	12.8	0	-12.15	12.8	0.13779528
GW	245	7	0	-4.371e-15	10.8	0	9.5	10.8	0.13779528
GW	246	1	0	9.5	10.8	0	9.75	11.05	0.13779528
GW	247	1	0	9.75	11.05	0	9.75	11.55	0.13779528
GW	248	1	0	9.75	11.55	0	9.5	11.8	0.13779528
GW	249	1	0	9.5	11.8	0	8	11.8	0.13779528
GW	250	1	0	8	11.8	0	7.75	12.05	0.13779528
GW	251	1	0	7.75	12.05	0	7.75	12.55	0.13779528
GW	252	1	0	7.75	12.55	0	8	12.8	0.13779528
GW	253	3	0	8	12.8	0	12.15	12.8	0.13779528
GW	254	7	0	-4.371e-15	49.2	0	9.5	49.2	0.13779528
GW	255	1	0	9.5	49.2	0	9.75	48.95	0.13779528
GW	256	1	0	9.75	48.95	0	9.75	48.45	0.13779528
GW	257	1	0	9.75	48.45	0	9.5	48.2	0.13779528
GW	258	1	0	9.5	48.2	0	8	48.2	0.13779528
GW	259	1	0	8	48.2	0	7.75	47.95	0.13779528
GW	260	1	0	7.75	47.95	0	7.75	47.45	0.13779528
GW	261	1	0	7.75	47.45	0	8	47.2	0.13779528
GW	262	3	0	12.15	47.2	0	8	47.2	0.13779528
GW	263	7	0	-4.371e-15	49.2	0	-9.5	49.2	0.13779528
GW	264	1	0	-9.5	49.2	0	-9.75	48.95	0.13779528
GW	265	1	0	-9.75	48.95	0	-9.75	48.45	0.13779528
GW	266	1	0	-9.75	48.45	0	-9.5	48.2	0.13779528
GW	267	1	0	-9.5	48.2	0	-8	48.2	0.13779528
GW	268	1	0	-8	48.2	0	-7.75	47.95	0.13779528
GW	269	1	0	-7.75	47.95	0	-7.75	47.45	0.13779528
GW	270	1	0	-7.75	47.45	0	-8	47.2	0.13779528
GW	271	3	0	-8	47.2	0	-12.15	47.2	0.13779528
GW	272	23	-9.5	-14	30	-9.5	15.5	30	0.13779528
GW	273	23	-9.5	-14	22.8	-9.5	15.5	22.8	0.13779528
GW	274	23	-9.5	-36.1	33	-9.5	-4.6	33	0.13779528
GW	275	23	-9.5	4	33	-9.5	35.5	33	0.13779528
GW	276	23	-9.5	-36.2	27	-9.5	-4.7	27	0.13779528
GW	277	23	-9.5	4	27	-9.5	35.5	27	0.13779528
GW	278	23	-9.5	-36.8	36	-9.5	-6.8	36	0.13779528
GW	279	23	-9.5	-36.9	24	-9.5	-6.9	24	0.13779528
GW	280	23	-9.5	6.3	24	-9.5	36.3	24	0.13779528
GW	281	23	-9.5	6.1	36	-9.5	36.1	36	0.13779528
GW	282	23	-9.5	-14.6	37.2	-9.5	14.9	37.2	0.13779528
GW	283	25	-9.5	-16	1	-9.5	16	1	0.13779528
GW	284	25	-9.5	-16	59	-9.5	16	59	0.13779528
GW	285	9	-4	12.5	32	-4	0.5	32	0.13779528
GW	286	9	-4	-0.5	32	-4	-12.5	32	0.13779528
GW	287	9	-4	12.5	28	-4	0.5	28	0.13779528
GW	288	9	-4	-0.5	28	-4	-12.5	28	0.13779528
GW	289	9	-4	12.5	41	-4	0.5	41	0.13779528
GW	290	9	-4	-0.5	41	-4	-12.5	41	0.13779528
GW	291	9	-4	12.5	38	-4	0.5	38	0.13779528
GW	292	9	-4	-0.5	38	-4	-12.5	38	0.13779528
GW	293	9	-4	12.5	22	-4	0.5	22	0.13779528
GW	294	9	-4	-0.5	22	-4	-12.5	22	0.13779528
GW	295	9	-4	12.5	19	-4	0.5	19	0.13779528
GW	296	9	-4	-0.5	19	-4	-12.5	19	0.13779528
GW	297	9	-4	12.5	54	-4	0.5	54	0.13779528
GW	298	9	-4	-0.5	54	-4	-12.5	54	0.13779528
GW	299	9	-4	12.5	35	-4	0.5	35	0.13779528
GW	300	9	-4	-0.5	35	-4	-12.5	35	0.13779528
GW	301	9	-4	12.5	25	-4	0.5	25	0.13779528
GW	302	9	-4	-0.5	25	-4	-12.5	25	0.13779528
GW	303	9	-4	12.5	6	-4	0.5	6	0.13779528
GW	304	9	-4	-0.5	6	-4	-12.5	6	0.13779528
GW	305	19	-9.5	-26.5	57	-9.5	-1	57	0.13779528
GW	306	19	-9.5	1	57	-9.5	26.5	57	0.13779528
GW	307	19	-9.5	-26.5	3	-9.5	-1	3	0.13779528
GW	308	19	-9.5	1	3	-9.5	26.5	3	0.13779528
GW	309	25	-9.5	-16	55	-9.5	16	55	0.13779528
GW	310	19	-9.5	-26.5	53	-9.5	-1	53	0.13779528
GW	311	19	-9.5	1	53	-9.5	26.5	53	0.13779528
GW	312	25	-9.5	-16	5	-9.5	16	5	0.13779528
GW	313	19	-9.5	-26.5	7	-9.5	-1	7	0.13779528
GW	314	19	-9.5	1	7	-9.5	26.5	7	0.13779528
GW	315	23	1	-0.75	30	1	-0.75	0	0.05094856
GW	316	23	1	-0.75	0	1	-0.75	-30	0.05094856
GW	317	23	1	0.75	30	1	0.75	0	0.05094856
GW	318	23	1	0.75	0	1	0.75	-30	0.05094856
GW	319	3	1	-0.75	0	1	0.75	0	0.14464842
GW	320	3	0	2.20475	30	1	0.75	30	0.05094856
GW	321	3	0	-2.2046988	30	1	-0.75	30	0.05094856
GW	322	3	0	2.20475	-30	1	0.75	-30	0.05094856
GW	323	3	0	-2.2046988	-30	1	-0.75	-30	0.05094856
GS	0	0	0.0254		' All in in.
GE	0
EK
LD	5	0	0	0	2.49e7	0
EX	0	319	2	0	1	0
GN	-1
FR	0	7	0	0	177	6
RP 0 1 73 1510 90 0 1 5 0 0

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300ohm

· #292 · Aug 20, 2009

The beamwidth pattern for channel 7 is incredibly wide for 13 dbi antenna ! (other vhf-hi channel patterns are very wide too)
You should have no problems aiming for it, heh.
Thats pretty good. On the K7MEM site, you would need a 225 inch long yagi to get 13dbi at 177mhz.

The Vhf_Hi raw gain :

The Vhf_Hi SWR :

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3

300ohm

· #293 · Aug 20, 2009

UHF raw gain:

UHF SWR:

And the picture, 118 inches tall :

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3

Xauto

· #294 · Aug 20, 2009

Well I'm not building this one in my bacement. At 6'X10' I would not be able to get it out. I had a hard time with a 50gal. hot water heater. The stairwell is in the wrong place. It would be nice to see.

Reactions: 1

stampeder

Discussion Starter · #295 · Aug 20, 2009

X-271 looks like the kind of awesome antenna that only a ship-in-a-bottle builder would have the patience to build!

wildwillie

· #296 · Aug 20, 2009

300ohms i started on the phase lines and was straightening them up then i lost everything .I was not a happy camper at that time, thank you for running the test.
300ohms i see you had to use the full reflectors i was thinking about getting away with one of the center reflectors in the middle of the phase line run .Not sure but it may help to shorten the hieght up. or did you look at that?
stampeder thank you for opening up area51
Xauto just as you told me dont give up

Oh on Jeds site i built his gapless SBGH, when I first jioned the forums and thought I already have the antenna so i wonder what it would do just as is with out his UHF reflectors.
HIs VHF Hi, was way out there at 133 SWR
I managed 10.21dbi with an SWR of 1.42, AGT 1.04 (0.18)
the antenne with reflectors is only 40 inches tall with the reflectors set back at 15 inches with an over all wideth of 71 inches.

Well I'm not building this one in my bacement

hehe well you'll have to build here up on the roof hehe

Xauto
Heres a look at the SBGH VHF-Hi only

Code:

CM useing antenna hov15-hovzz3-RgaplessN12z2_D7mm_diffevol,no UHF reflectors
CM design by John E. Davis.
CM VHF-HI only smaller in size
CM reflector design by wildwillie
CE
GW	1	3	0	-1.6515516	-1.0023e-3	0	1.15155075	-1.0023e-3	0.08101142
GW	2	7	0	-1.6515516	-1.0023e-3	0	-7.970276	6.31773784	0.08101142
GW	3	7	0	-1.6515516	-1.0023e-3	0	-7.970276	-6.3197425	0.08101142
GW	4	7	0	1.15155075	-1.0023e-3	0	7.47027516	6.31773784	0.08101142
GW	5	7	0	1.15155075	-1.0023e-3	0	7.47027516	-6.3197425	0.08101142
GW	6	7	0	-7.970276	6.31773784	0	-2.5663075	11.7217142	0.08101142
GW	7	7	0	-7.970276	-6.3197425	0	-2.5663075	-11.72372	0.08101142
GW	8	7	0	7.47027516	6.31773784	0	2.06630666	11.7217142	0.08101142
GW	9	7	0	7.47027516	-6.3197425	0	2.06630666	-11.72372	0.08101142
GW	10	5	0	-2.5663075	11.7217142	0	-7.4890555	16.6444701	0.08101142
GW	11	5	0	-2.5663075	-11.72372	0	-7.4890555	-16.646475	0.08101142
GW	12	5	0	2.06630666	11.7217142	0	6.98905469	16.6444701	0.08101142
GW	13	5	0	2.06630666	-11.72372	0	6.98905469	-16.646475	0.08101142
GW	14	5	0	-7.4890555	16.6444701	0	-12.362717	16.6444701	0.08101142
GW	15	5	0	-7.4890555	-16.646475	0	-12.362717	-16.646475	0.08101142
GW	16	5	0	6.98905469	16.6444701	0	11.8627161	16.6444701	0.08101142
GW	17	5	0	6.98905469	-16.646475	0	11.8627161	-16.646475	0.08101142
GW	130	5	0	-12.7071	17.2262121	0	-6.3678505	17.2264524	0.1377953
GW	131	1	0	-6.3678505	17.2264524	0	-6.1178505	17.4764524	0.1377953
GW	132	1	0	-6.1178505	17.4764524	0	-6.1178505	17.9764524	0.1377953
GW	133	1	0	-6.1178505	17.9764524	0	-6.3678505	18.2264524	0.1377953
GW	135	1	0	-6.3678505	18.2264524	0	-7.8763324	18.1915048	0.1377953
GW	136	1	0	-7.8763324	18.1915048	0	-8.1263324	18.4415048	0.1377953
GW	137	1	0	-8.1263324	18.4415048	0	-8.1263324	18.9415048	0.1377953
GW	138	1	0	-8.1263324	18.9415048	0	-7.8763324	19.1915048	0.1377953
GW	139	7	0	-7.8763324	19.1915048	0	-0.1354847	19.1966725	0.1377953
GW	140	19	-15	-2.3155823	2.78757514	-15	-26	2.86773567	0.08101142
GW	141	17	-15	26	2.86773567	-15	2.68441768	2.78757514	0.08101142
GW	142	19	-15	-2.3155823	-3.2124249	-15	-26	-3.1322644	0.08101142
GW	143	17	-15	26	-3.1322644	-15	2.68441768	-3.2124249	0.08101142
GW	162	23	-15	-5.3155823	5.78757514	-15	-36	5.86773567	0.08101142
GW	163	23	-15	35	5.86773567	-15	4.68441768	5.78757514	0.08101142
GW	164	23	-15	-5.3155823	-6.2124249	-15	-36	-6.1322644	0.08101142
GW	165	23	-15	35	-6.1322644	-15	4.68441768	-6.2124249	0.08101142
GW	166	23	-15	-4	14.8677356	-15	-32.684418	14.9478961	0.08101142
GW	167	21	-15	32.3155823	14.9478961	-15	4	14.8677356	0.08101142
GW	168	23	-15	-3.3155823	-14.212425	-15	-32	-14.132264	0.08101142
GW	169	21	-15	31.0655823	-14.052103	-15	3	-14.132264	0.08101142
GW	170	23	-15	14.6844177	19.2875751	-15	-15.265582	19.2875751	0.08101142
GW	171	23	-15	14.6844177	-19.212425	-15	-15.265582	-19.212425	0.08101142
GW	172	29	-15	17.6923072	-0.0446894	-15	-18.99211	0.05611243	0.08101142
GW	173	23	-15	13.9999997	4.86773567	-15	-15	4.86773567	0.08101142
GW	174	23	-15	13.9999997	-5.1322644	-15	-15	-5.1322644	0.08101142
GW	193	5	0	12.4185357	17.2216672	0	6.07928575	17.2219075	0.1377953
GW	194	1	0	6.07928575	17.2219075	0	5.82928575	17.4719075	0.1377953
GW	195	1	0	5.82928575	17.4719075	0	5.82928575	17.9719075	0.1377953
GW	196	1	0	5.82928575	17.9719075	0	6.07928575	18.2219075	0.1377953
GW	197	1	0	6.07928575	18.2219075	0	7.58776764	18.1869599	0.1377953
GW	198	1	0	7.58776764	18.1869599	0	7.83776764	18.4369599	0.1377953
GW	199	1	0	7.83776764	18.4369599	0	7.83776764	18.9369599	0.1377953
GW	200	1	0	7.83776764	18.9369599	0	7.60536291	19.1915048	0.1377953
GW	201	7	0	7.60536291	19.1915048	0	-0.1354847	19.1966725	0.1377953
GW	202	5	0	12.4974319	-17.165553	0	6.15818187	-17.165793	0.1377953
GW	203	1	0	6.15818187	-17.165793	0	5.90818187	-17.415793	0.1377953
GW	204	1	0	5.90818187	-17.415793	0	5.90818187	-17.915793	0.1377953
GW	205	1	0	5.90818187	-17.915793	0	6.15818187	-18.165793	0.1377953
GW	206	1	0	6.15818187	-18.165793	0	7.66666376	-18.130846	0.1377953
GW	207	1	0	7.66666376	-18.130846	0	7.91666376	-18.380846	0.1377953
GW	208	1	0	7.91666376	-18.380846	0	7.91666376	-18.880846	0.1377953
GW	209	1	0	7.91666376	-18.880846	0	7.66666376	-19.130846	0.1377953
GW	210	7	0	7.66666376	-19.130846	0	-0.0741839	-19.136014	0.1377953
GW	211	5	0	-12.628204	-17.161008	0	-6.2889544	-17.161249	0.1377953
GW	212	1	0	-6.2889544	-17.161249	0	-6.0389544	-17.411249	0.1377953
GW	213	1	0	-6.0389544	-17.411249	0	-6.0389544	-17.911249	0.1377953
GW	214	1	0	-6.0389544	-17.911249	0	-6.2889544	-18.161249	0.1377953
GW	215	1	0	-6.2889544	-18.161249	0	-7.7974362	-18.126301	0.1377953
GW	216	1	0	-7.7974362	-18.126301	0	-8.0474362	-18.376301	0.1377953
GW	217	1	0	-8.0474362	-18.376301	0	-8.0474362	-18.876301	0.1377953
GW	218	1	0	-8.0474362	-18.876301	0	-7.8150315	-19.130846	0.1377953
GW	219	7	0	-7.8150315	-19.130846	0	-0.0741839	-19.136014	0.1377953
GW	220	21	-15	12.8934905	-11.132264	-15	-14.10651	-11.132264	0.08101142
GW	221	21	-15	12.9467463	10.8677356	-15	-14.053254	10.8677356	0.08101142
GS	0	0	0.0254		' All in in.
GE	0
EK
LD	5	0	0	0	2.49e7	0
EX	0	1	2	0	1	0
GN	-1
FR	0	1	0	0	177	0
RP 0 1 36 1001 90 0 5.0 10 10000 0

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300ohm

· #297 · Aug 20, 2009

Not sure but it may help to shorten the hieght up. or did you look at that?

Yeah, but it only saved 2 inches, and knocked a tenth of dbi off of channel 7 gain. At that size, might as well use the whole 10ft piece of pipe. Why make another cut ? heh.

X-271 looks like the kind of awesome antenna that only a ship-in-a-bottle builder would have the patience to build!

Heh, yep. On the other hand, its still a whole lot easier than building a CM4251 AND a 225 inch long yagi, heh.
It hasnt been completely optimized and there does seem to be a whole lot of metal in the reflector that may possibly be reduced.

Walter Dnes

· #298 · Aug 21, 2009

X-283 8-whisker Bowtie with Corner Reflector channels 14-69

Here's my latest effort. The 8-whisker bowtie seems to keep SWR down, which is why I use it here. As is usually the case, I eventually found that the best gain was concentrated at one end of the UHF spectrum. That's where the SKALE variable saved me again, allowing me to adjust the size to centre the gain around the middle of the UHF band. The gain is sharply directional, 12 to 14 db for the entire band, and maximum SWR around 2.1. Here it is...

Code:

CM 8-Whisker Bowtie with corner reflector
CE
SY E_RAD=0.05
SY FEED=1
SY FB2=FEED/2
SY ANGL=24.0
SY ANGL3=ANGL/3
SY COS_ANGL=COS(ANGL)
SY COS_ANGL3=COS(ANGL3)
SY SIN_ANGL=SIN(ANGL)
SY SIN_ANGL3=SIN(ANGL3)
SY BASE_E_LEN=8.5
SY BASE_R_LEN=12
SY BASE_RX_SEP=7.5
SY BASE_RY_SEP=1.5
SY BASE_DELTA_X=8.5
SY BASE_K=1.125
SY SKALE=1.15
SY E_LEN=BASE_E_LEN*SKALE
SY R_LEN=BASE_R_LEN*SKALE
SY RX_SEP=BASE_RX_SEP*SKALE
SY RY_SEP=BASE_RY_SEP*SKALE
SY ZZ1=E_LEN*SIN_ANGL
SY YY1=E_LEN*COS_ANGL+FB2
SY DELTA_X=BASE_DELTA_X*SKALE
SY K=BASE_K*SKALE
GW  3 5 0 -FB2  0 0 -E_LEN*COS_ANGL-FB2 E_LEN*SIN_ANGL3 E_RAD
GW  4 5 0 FB2 0 0 E_LEN*COS_ANGL+FB2  E_LEN*SIN_ANGL3 E_RAD
GW  5 5 0 -FB2  0 0 -YY1  ZZ1 E_RAD
GW  6 5 0 FB2 0 0 YY1 ZZ1 E_RAD
GW  7 19  -RX_SEP+DELTA_X-7*K -R_LEN  RY_SEP  -RX_SEP+DELTA_X-7*K R_LEN RY_SEP  E_RAD
GW  8 19  -RX_SEP+DELTA_X-6*K -R_LEN  RY_SEP*2  -RX_SEP+DELTA_X-6*K R_LEN RY_SEP*2  E_RAD
GW  9 19  -RX_SEP+DELTA_X-5*K -R_LEN  RY_SEP*3  -RX_SEP+DELTA_X-5*K R_LEN RY_SEP*3  E_RAD
GW  10  19  -RX_SEP+DELTA_X-4*K -R_LEN  RY_SEP*4  -RX_SEP+DELTA_X-4*K R_LEN RY_SEP*4  E_RAD
GW  11  19  -RX_SEP+DELTA_X-3*K -R_LEN  RY_SEP*5  -RX_SEP+DELTA_X-3*K R_LEN RY_SEP*5  E_RAD
GW  12  19  -RX_SEP+DELTA_X-2*K -R_LEN  RY_SEP*6  -RX_SEP+DELTA_X-2*K R_LEN RY_SEP*6  E_RAD
GW  13  19  -RX_SEP+DELTA_X-1*K -R_LEN  RY_SEP*7  -RX_SEP+DELTA_X-1*K R_LEN RY_SEP*7  E_RAD
GW  14  19  -RX_SEP+DELTA_X -R_LEN  RY_SEP*8  -RX_SEP+DELTA_X R_LEN RY_SEP*8  E_RAD
GX  13  001
GW  1 1 0 -FB2  0 0 FB2 0 E_RAD
GW  2 21  -RX_SEP+DELTA_X-8*K -R_LEN  0 -RX_SEP+DELTA_X-8*K R_LEN 0 E_RAD
GS  0 0 0.0254    ' All in in.
GE  0
EK
EX  0 1 1 0 1 0
GN  -1
FR  0 1 0 0 470 6
RP  0 1 37  1501  90. 0.  0.  10. 0.  0.

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3

Xauto

· #299 · Aug 21, 2009

Walter: Have you played with closing the ends. I'm using your elements with a 8" piece of wire across the ends for my SDTv.

bokakob

· #300 · Aug 21, 2009

Thanks very much!

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