Area 51 for Antenna Modelers & Builders (See Post #1) - Page 52 - Canadian TV, Computing and Home Theatre Forums

balm · 2010-01-21, 03:35 PM

OTA, im trying several variations, but so far no go, all of them destroy the UHFs...

the mast is not part of the modeling.

ota_canuck · 2010-01-21, 03:47 PM

Maybe those Narods [being in character with traditional horizontal orientation of VHF antenna elements] can not be used in a bent 'V' form. If the Narods where placed behind the 9" horizontal elements perhaps or possibly just lengthen those 9" element to 14.5" elements.

nikiml · 2010-01-21, 05:06 PM

below is a nec for x739, parametrized:

CM "Centerpede" HDTV Antenna
CM Copyright 2010 BOKAKOB
CM
CM P-multip 12 18 -0.125 -0.6 -0.9 -0.125 0.6 -0.9 -0.125 0.6 0.9 0 0
CE
SY scale=1
SY dlen=.24
SY zzgap=.025
SY dgap=.01
SY y=.265
SY dz=.110
SY zspace=.03
SY feed_gap=.015
SY feedx=-.005
SY feed_gap1=.005
SY feed_gap2=.01

SY _dlen1=1
SY _dlen2=1
SY dlen1=dlen*scale*_dlen1
SY dlen2=dlen*scale*_dlen2
SY _zzgap1=1
SY _zzgap2=1
SY _zzgap3=1
SY zzgap1=zzgap*scale*_zzgap1
SY zzgap2=zzgap*scale*_zzgap2
SY zzgap3=zzgap*scale*_zzgap3
SY _y1=1
SY _y3=1
SY _y5=1
SY y1=y*scale*_y1
SY y3=y*scale*_y3
SY y5=y*scale*_y5
SY _dz1=1
SY dz1=dz*scale*_dz1
SY _dz2=1
SY dz2=dz*scale*_dz2
SY _dz3=1
SY dz3=dz*scale*_dz3
SY _dz4=1
SY dz4=dz*scale*_dz4
SY _dz5=1
SY dz5=dz*scale*_dz5
SY _zspace1=1
SY _zspace2=1
SY zspace1=zspace*scale*_zspace1
SY zspace2=zspace*scale*_zspace1
SY z0=zspace1*.5
SY z1=z0+dz1
SY z2=z1+dz2
SY z3=z2+zspace2
SY z4=z3+dz3
SY z5=z4+dz4
SY z6=z5+dz5
SY zzradius=1.02626e-3
SY dradius=1.02626e-3
SY zfeed=(z1+z4)/2
GW 1 0 0 y1 0 0 y1 z0 zzradius
GW 2 0 0 y1 z0 0 zzgap1 z1 zzradius
GW 3 0 0 zzgap1 z1 0 dgap z1 dradius
GW 4 0 0 zzgap1 z1 0 zzgap1+dlen1 z1 dradius
GW 5 0 0 zzgap1 z1 0 y3 z2 zzradius
GW 6 0 0 y3 z2 0 y3 z3 zzradius
GW 7 0 0 y3 z3 0 zzgap2 z4 zzradius
GW 8 0 0 zzgap2 z4 0 dgap z4 dradius
GW 9 0 0 zzgap2 z4 0 zzgap2+dlen2 z4 dradius
GW 10 0 0 zzgap2 z4 0 y5 z5 zzradius
GW 11 0 0 y5 z5 0 zzgap3 z6 zzradius
GW 12 0 0 dgap z1 0 feed_gap zfeed dradius
GW 13 0 0 dgap z4 0 feed_gap zfeed dradius
GW 14 0 0 feed_gap zfeed feedx feed_gap1 zfeed dradius
GW 15 0 feedx feed_gap1 zfeed feedx feed_gap2 0 dradius
GX 20 010
GX 40 001
GW 100 3 feedx feed_gap2 0 feedx -feed_gap2 0 2*dradius
GE 0
GN -1
EK
EX 0 100 2 0 1 0
FR 0 0 0 0 470 0
EN

nikiml · 2010-01-21, 10:12 PM

ok. so this model needs more work.

thanks for teaching me balm.

balm · 2010-01-21, 11:23 PM

nikiml,

your AGT drops those numbers by 3-4 dbi, no?

ota_canuck · 2010-01-22, 01:28 AM

Quote:

Originally Posted by 300ohm

Yeah, especially the lower channels. Probably some different bending of the same 29 inch NAROD is in order. (The 29 inch size should be about right) Maybe bending it such that only 5 inches of the NAROD leg are parallel to each element leg like in the SBGH ?

I made some adjustments. Reformed the 29" Narods and closed up the phase line & feed gaps to 1".

Bi-directional with No reflector

Seems to be improved somewhat from my first try.

OK,.. this is what I have now. All are above 50% unless noted otherwise. Most are 100%.

Antenna aim NNE forward aim toward Toronto/ rear is facing toward Erie. Antenna at 20ft elevation.
If I reverse the antenna 180° I still get the same result.
If I aim the antenna more to the east, I can actually get ION which is 80+ miles away.

2.1/.2/.3 WGRZ Buffalo 100%
4.1 WIVB Buffalo 100%
5.1 CBC Toronto 70%
7.1 WKBW Buffalo 100%
9.1 Toronto [just a sniff] 10%
11.1 CHCH Hamilton 100%
12.1/.2/.2 Erie WICU/CW/WSEE 80%
15.1 SUN Hamilton 50%
17.1/.2/.3 WNED Buffalo 100%
23.1 CW Buffalo 100%
26.1/.2 TCT Hamilton 90%
29.1/.2 Fox Buffalo 100%
35.1/.2 Erie WSEE/CW 100%
36.1 CTC Hamilton 100%
44.1 Toronto [just a sniff] 10%
49.1/.2 MyTV Buffalo 80%
51.1/.2/.3/.4 [ION only if I pinpoint toward Batavia] 50%
54.1/.2/.3 WQLN Erie 100%
66.1 [Fox 66 Erie] 100%

bokakob · 2010-01-22, 02:49 PM

I had a bit of time and I made a comparison between SBGH and "Centipede."
Both models were brought to a common denomiantor and the picture snaps were made with the same settings. This is not an "experimental models." I have built "Centipede" and it works -- so I think it deserves its own thread for people to know. I am sure that "Centipede" could be much improved.
It would be nice if this comparison composite result wouldn't be burried in the hundreds of posts of the "Area 51" becuse the results are speaking pretty clearly. The file used for comparison is listed below the composite picture for those who what to try doing this task.

I would like to thank all the people who helped me in honing this antenna into a robust workhorse.

Thanks for reading.

Input deck:

CM the following is the combined file to compare "Centipede" and "SBGH"
CM "Centipede" occupies elements 1-999
CM "SBGH" occupies elements 1000-2000
CE
GW 2 13 0 0.4 -0.125 0 0.65 -0.125 1.02626e-3
GW 3 15 0 0.4 -0.125 0 0.64 0 1.02626e-3
GW 4 15 0 0.4 -0.125 0 0.64 -0.25 1.02626e-3
GW 5 13 0 0.4 0.125 0 0.65 0.125 1.02626e-3
GW 6 15 0 0.4 0.125 0 0.64 0.25 1.02626e-3
GW 7 15 0 0.4 0.125 0 0.64 0 1.02626e-3
GW 8 2 0 0.38 -0.125 0 0.4 -0.125 1.02626e-3
GW 9 2 0 0.38 0.125 0 0.4 0.125 1.02626e-3
GW 10 7 0 0.38 -0.125 0 0.385 0 1.02626e-3
GW 11 7 0 0.385 0 0 0.38 0.125 1.02626e-3
GW 12 15 0 0.41869626 -0.3650552 0 0.64 -0.25 1.02626e-3
GW 13 15 0 0.41869626 0.36505518 0 0.64 0.25 1.02626e-3
GW 14 13 0 0.35 -0.125 0 0.1 -0.125 1.02626e-3
GW 15 15 0 0.35 -0.125 0 0.11 0 1.02626e-3
GW 16 15 0 0.35 -0.125 0 0.11 -0.25 1.02626e-3
GW 17 13 0 0.35 0.125 0 0.1 0.125 1.02626e-3
GW 18 15 0 0.35 0.125 0 0.11 0.25 1.02626e-3
GW 19 15 0 0.35 0.125 0 0.11 0 1.02626e-3
GW 20 2 0 0.37 -0.125 0 0.35 -0.125 1.02626e-3
GW 21 2 0 0.37 0.125 0 0.35 0.125 1.02626e-3
GW 22 7 0 0.37 -0.125 0 0.365 0 1.02626e-3
GW 23 7 0 0.365 0 0 0.37 0.125 1.02626e-3
GW 24 15 0 0.3313037 -0.3650552 0 0.11 -0.25 1.02626e-3
GW 25 15 0 0.3313037 0.36505518 0 0.11 0.25 1.02626e-3
GW 1 1 0 0.365 0 0 0.385 0 1.02626e-3
GW 1000 8 0 -0.546 -0.381 0 -0.688 -0.381 1.02626e-3
GW 1001 11 0 -0.546 -0.381 0 -0.419 -0.254 1.02626e-3
GW 1002 11 0 -0.546 0.381 0 -0.419 0.254 1.02626e-3
GW 1003 11 0 -0.419 -0.254 0 -0.546 -0.127 1.02626e-3
GW 1004 11 0 -0.419 0 0 -0.546 0.127 1.02626e-3
GW 1005 11 0 -0.546 0.127 0 -0.419 0.254 1.02626e-3
GW 1006 11 0 -0.419 0 0 -0.546 -0.127 1.02626e-3
GW 1007 8 0 -0.546 0.381 0 -0.688 0.381 1.02626e-3
GW 1008 5 0 -0.384 0 0 -0.419 0 1.02626e-3
GW 1009 8 0 -0.204 -0.381 0 -0.062 -0.381 1.02626e-3
GW 1010 11 0 -0.204 -0.381 0 -0.331 -0.254 1.02626e-3
GW 1011 11 0 -0.204 0.381 0 -0.331 0.254 1.02626e-3
GW 1012 11 0 -0.331 -0.254 0 -0.204 -0.127 1.02626e-3
GW 1013 11 0 -0.331 0 0 -0.204 0.127 1.02626e-3
GW 1014 11 0 -0.204 0.127 0 -0.331 0.254 1.02626e-3
GW 1015 11 0 -0.331 0 0 -0.204 -0.127 1.02626e-3
GW 1016 8 0 -0.204 0.381 0 -0.062 0.381 1.02626e-3
GW 1017 5 0 -0.366 0 0 -0.331 0 1.02626e-3
GW 1018 3 0 -0.384 0 0 -0.366 0 1.02626e-3
GE 0
EK
EX 0 1 1 0 1 0
EX 0 1018 2 0 1 0
GN -1
FR 0 1 0 0 585 0

ota_canuck · 2010-01-22, 06:31 PM

bokakob,

kudos,.. good job and a great antenna design performance comparison.

ota_canuck · 2010-01-22, 06:59 PM

It appears that the centipede design focuses the horizontal forward gains rather than vertical gains. That could be good for some specific reception needs and bad for others who need to catch weaker overhead signals.

Maybe I'm reading to much into this, but this probably means that overall antenna height is a bit more important for the centipede antenna design than it would be for the Hoverman design.

FranKllr · 2010-01-22, 08:57 PM

Including VHF-Hi gain from the Centipede serie would be nice.

ota_canuck · 2010-01-22, 09:04 PM

Quote:

Originally Posted by FranKllr

Including VHF-Hi gain from the Centipede serie would be nice.

See posts #767 & #776. It's in the works. Hopefully a combined VHF/UHF success is on the horizon soon.

300ohm · 2010-01-22, 09:47 PM

Quote:

I had a bit of time and I made a comparison between SBGH and "Centipede."

Nice job on the comparison. They are very comparable with the Centipede having better low channel gain. And with no free standing stubs and a four point mounting vs three, it would be sturdier structually. I wouldnt use 12 gauge wire on either of the outdoor builds though, I would go for at least 10 ga or thicker.
It would also make a very decent foldable antenna design if it wasnt for the trickier feed lines.

FranKllr · 2010-01-22, 10:06 PM

Quote:

Originally Posted by ota_canuck

See posts #767 & #776. It's in the works. Hopefully a combined VHF/UHF success is on the horizon soon.

Well, was looking for something like:

Code:

CH Freq   Raw  SWR   Net
 7  174  5.07 3.76  3.29
 8  180  4.92 3.28  3.47
 9  186  4.83 3.01  3.57
10  192  4.80 2.81  3.69
11  198  4.81 2.62  3.84
12  204  4.86 2.43  4.03
13  210  4.94 2.23  4.26
 -       5.08 2.03  4.55


14  470  7.16 2.38  6.37
15  476  7.57 2.23  6.89
16  482  7.79 2.15  7.17
17  488  7.93 2.10  7.35
18  494  8.03 2.07  7.47
19  500  8.12 2.06  7.56
20  506  8.21 2.06  7.65
21  512  8.28 2.07  7.71
22  518  8.36 2.09  7.78
23  524  8.43 2.11  7.84
24  530  8.50 2.13  7.89
25  536  8.57 2.15  7.95
26  542  8.63 2.18  7.99
27  548  8.69 2.20  8.03
28  554  8.74 2.22  8.06
29  560  8.77 2.25  8.08
30  566  8.78 2.26  8.07
31  572  8.78 2.28  8.06
32  578  8.77 2.28  8.05
33  584  8.78 2.26  8.08
34  590  8.86 2.22  8.19
35  596  9.04 2.16  8.41
36  602  9.30 2.10  8.72
37  608  9.58 2.04  9.04
38  614  9.84 1.99  9.34
39  620 10.05 1.94  9.58
40  626 10.22 1.90  9.78
41  632 10.37 1.86  9.96
42  638 10.49 1.82 10.10
43  644 10.60 1.78 10.24
44  650 10.69 1.73 10.36
45  656 10.76 1.69 10.46
46  662 10.83 1.65 10.56
47  668 10.88 1.61 10.64
48  674 10.92 1.58 10.70
49  680 10.95 1.55 10.74
50  686 10.97 1.55 10.76
51  692 10.97 1.56 10.76
52  698 10.95 1.60 10.71
53  704 10.91 1.66 10.63

Code:

CM ota_canuck x776
CM AGT 587 rad 1.15242
CM AGT 195 rad 1.11
CE
GW	1	9	0	0.04445	-0.127	0	0.2645	0	1.15242e-3
GW	2	9	0	0.2645	0	0	0.04445	0.127	1.15242e-3
GW	3	9	0	0.04445	0.127	0	0.2645	0.254	1.15242e-3
GW	4	9	0	0.2645	0.254	0	0.04445	0.381	1.15242e-3
GW	5	9	0	0.04445	-0.127	0	0.2645	-0.254	1.15242e-3
GW	6	9	0	0.2645	-0.254	0	0.04445	-0.381	1.15242e-3
GW	7	9	0	-0.04445	-0.127	0	-0.2645	0	1.15242e-3
GW	8	9	0	-0.2645	0	0	-0.0445	0.127	1.15242e-3
GW	9	9	0	-0.0445	0.127	0	-0.2645	0.254	1.15242e-3
GW	10	9	0	-0.2645	0.254	0	-0.04445	0.381	1.15242e-3
GW	11	9	0	-0.04445	-0.127	0	-0.2645	-0.254	1.15242e-3
GW	12	9	0	-0.2645	-0.254	0	-0.04445	-0.381	1.15242e-3
GW	13	9	0	0.04445	0.127	0	0.27305	0.127	1.15242e-3
GW	14	9	0	0.04445	-0.127	0	0.27305	-0.127	1.15242e-3
GW	15	9	0	-0.0445	0.127	0	-0.27305	0.127	1.15242e-3
GW	16	9	0	-0.04445	-0.127	0	-0.27305	-0.127	1.15242e-3
GW	17	7	0	-0.01275	0.127	0	-0.0127	0	1.15242e-3
GW	18	7	0	-0.0127	0	0	-0.0127	-0.127	1.15242e-3
GW	19	7	0	0.0127	0.127	0	0.0127	0	1.15242e-3
GW	20	7	0	0.0127	0	0	0.0127	-0.127	1.15242e-3
GW	21	5	0	-0.0127	0	0	0.0127	0	1.15242e-3
GW	26	2	0	0.0127	0.127	0	0.04445	0.127	1.15242e-3
GW	27	2	0	0.0127	-0.127	0	0.04445	-0.127	1.15242e-3
GW	28	2	0	-0.01275	0.127	0	-0.0445	0.127	1.15242e-3
GW	30	2	0	-0.0127	-0.127	0	-0.04445	-0.127	1.15242e-3
GW	31	9	0	0.17599227	0.32092755	0	0	0.4225	1.15242e-3
GW	32	9	0	-0.1759923	0.32092755	0	0	0.4225	1.15242e-3
GW	33	8	0	0.17599227	0.32093	0	0.34109227	0.32093	1.15242e-3
GW	34	8	0	-0.1759923	0.32092755	0	-0.3410923	0.32092755	1.15242e-3
GW	35	9	0	0.17599227	-0.3209276	0	0	-0.4225	1.15242e-3
GW	36	9	0	-0.1759923	-0.3209276	0	0	-0.4225	1.15242e-3
GW	37	8	0	0.17599227	-0.32093	0	0.34109227	-0.32093	1.15242e-3
GW	38	8	0	-0.1759923	-0.3209276	0	-0.3410923	-0.3209276	1.15242e-3
GE	0
LD	5	0	0	0	58000000
GN	-1
EK
EX	0	21	3	0	1	0		
FR	0	0	0	0	587	0
EN

bokakob · 2010-01-22, 10:20 PM

This looks good! I made the elements a bit longer to gain a bit of signal at the low end giving up some gain at the high end. It makes the curve more horizontal.

Great work!

ota_canuck · 2010-01-23, 07:07 PM

This is awsome. I was testing the centipede antenna design through out the past week. I did some experiments using a 29" NAROD to try to capture VHF. I have now abandoned my three 4bay antenna array and replaced it with just one Bi-directional centipede. The front of the antenna is aimed NNE toward Toronto and the back is toward Erie PA.

Digital:
2.1/.2/.3 WGRZ Buffalo 100%
4.1 WIVB Buffalo 100%
5.1 CBC Toronto 100%
7.1 WKBW Buffalo 100%
9.1 CTV Toronto 60%
11.1 CHCH Hamilton 100%
12.1/.2/.2 Erie WICU/CW/WSEE 100%
15.1 SUN Hamilton 30%
17.1/.2/.3 WNED Buffalo 100%
23.1 CW Buffalo 80%
25 Toronto CBLTF 30%
26.1/.2 TCT Buffalo 100%
29.1/.2 Fox Buffalo 70%
35.1/.2 Erie WSEE/CW 100%
36.1 CTS Hamilton 100%
41.1 Global Toronto 20%
44.1 Omni-2 Toronto 40%
49.1/.2 MyTV Buffalo 80%
54.1/.2/.3 WQLN Erie 100%
57.1 CITY Toronto 15%
64.1 Omni[1] Toronto 15%
66.1 Fox 66 Erie 100%

Analog:
5, 6, 9 ,11, 13, 19, 28, 31, 36, 45, 47, 55, 57

2010-01-21, 05:06 PM	#768
nikiml Join Date: Dec 2008 Location: mississauga, ON Posts: 721	x-739 parametrized below is a nec for x739, parametrized: CM "Centerpede" HDTV Antenna CM Copyright 2010 BOKAKOB CM CM P-multip 12 18 -0.125 -0.6 -0.9 -0.125 0.6 -0.9 -0.125 0.6 0.9 0 0 CE SY scale=1 SY dlen=.24 SY zzgap=.025 SY dgap=.01 SY y=.265 SY dz=.110 SY zspace=.03 SY feed_gap=.015 SY feedx=-.005 SY feed_gap1=.005 SY feed_gap2=.01 SY _dlen1=1 SY _dlen2=1 SY dlen1=dlenscale_dlen1 SY dlen2=dlenscale_dlen2 SY _zzgap1=1 SY _zzgap2=1 SY _zzgap3=1 SY zzgap1=zzgapscale_zzgap1 SY zzgap2=zzgapscale_zzgap2 SY zzgap3=zzgapscale_zzgap3 SY _y1=1 SY _y3=1 SY _y5=1 SY y1=yscale_y1 SY y3=yscale_y3 SY y5=yscale_y5 SY _dz1=1 SY dz1=dzscale_dz1 SY _dz2=1 SY dz2=dzscale_dz2 SY _dz3=1 SY dz3=dzscale_dz3 SY _dz4=1 SY dz4=dzscale_dz4 SY _dz5=1 SY dz5=dzscale_dz5 SY _zspace1=1 SY _zspace2=1 SY zspace1=zspacescale_zspace1 SY zspace2=zspacescale_zspace1 SY z0=zspace1.5 SY z1=z0+dz1 SY z2=z1+dz2 SY z3=z2+zspace2 SY z4=z3+dz3 SY z5=z4+dz4 SY z6=z5+dz5 SY zzradius=1.02626e-3 SY dradius=1.02626e-3 SY zfeed=(z1+z4)/2 GW 1 0 0 y1 0 0 y1 z0 zzradius GW 2 0 0 y1 z0 0 zzgap1 z1 zzradius GW 3 0 0 zzgap1 z1 0 dgap z1 dradius GW 4 0 0 zzgap1 z1 0 zzgap1+dlen1 z1 dradius GW 5 0 0 zzgap1 z1 0 y3 z2 zzradius GW 6 0 0 y3 z2 0 y3 z3 zzradius GW 7 0 0 y3 z3 0 zzgap2 z4 zzradius GW 8 0 0 zzgap2 z4 0 dgap z4 dradius GW 9 0 0 zzgap2 z4 0 zzgap2+dlen2 z4 dradius GW 10 0 0 zzgap2 z4 0 y5 z5 zzradius GW 11 0 0 y5 z5 0 zzgap3 z6 zzradius GW 12 0 0 dgap z1 0 feed_gap zfeed dradius GW 13 0 0 dgap z4 0 feed_gap zfeed dradius GW 14 0 0 feed_gap zfeed feedx feed_gap1 zfeed dradius GW 15 0 feedx feed_gap1 zfeed feedx feed_gap2 0 dradius GX 20 010 GX 40 001 GW 100 3 feedx feed_gap2 0 feedx -feed_gap2 0 2dradius GE 0 GN -1 EK EX 0 100 2 0 1 0 FR 0 0 0 0 470 0 EN Last edited by nikiml; 2010-01-21 at 05:15 PM. Reason: removed some redundant params

2010-01-21, 10:12 PM	#769
nikiml Join Date: Dec 2008 Location: mississauga, ON Posts: 721	ok. so this model needs more work. thanks for teaching me balm. Last edited by nikiml; 2010-01-22 at 01:13 AM.

2010-01-22, 02:49 PM	#772
bokakob Join Date: Aug 2009 Posts: 123	Centipede -- the next generation antenna I had a bit of time and I made a comparison between SBGH and "Centipede." Both models were brought to a common denomiantor and the picture snaps were made with the same settings. This is not an "experimental models." I have built "Centipede" and it works -- so I think it deserves its own thread for people to know. I am sure that "Centipede" could be much improved. It would be nice if this comparison composite result wouldn't be burried in the hundreds of posts of the "Area 51" becuse the results are speaking pretty clearly. The file used for comparison is listed below the composite picture for those who what to try doing this task. I would like to thank all the people who helped me in honing this antenna into a robust workhorse. Thanks for reading. Input deck: CM the following is the combined file to compare "Centipede" and "SBGH" CM "Centipede" occupies elements 1-999 CM "SBGH" occupies elements 1000-2000 CE GW 2 13 0 0.4 -0.125 0 0.65 -0.125 1.02626e-3 GW 3 15 0 0.4 -0.125 0 0.64 0 1.02626e-3 GW 4 15 0 0.4 -0.125 0 0.64 -0.25 1.02626e-3 GW 5 13 0 0.4 0.125 0 0.65 0.125 1.02626e-3 GW 6 15 0 0.4 0.125 0 0.64 0.25 1.02626e-3 GW 7 15 0 0.4 0.125 0 0.64 0 1.02626e-3 GW 8 2 0 0.38 -0.125 0 0.4 -0.125 1.02626e-3 GW 9 2 0 0.38 0.125 0 0.4 0.125 1.02626e-3 GW 10 7 0 0.38 -0.125 0 0.385 0 1.02626e-3 GW 11 7 0 0.385 0 0 0.38 0.125 1.02626e-3 GW 12 15 0 0.41869626 -0.3650552 0 0.64 -0.25 1.02626e-3 GW 13 15 0 0.41869626 0.36505518 0 0.64 0.25 1.02626e-3 GW 14 13 0 0.35 -0.125 0 0.1 -0.125 1.02626e-3 GW 15 15 0 0.35 -0.125 0 0.11 0 1.02626e-3 GW 16 15 0 0.35 -0.125 0 0.11 -0.25 1.02626e-3 GW 17 13 0 0.35 0.125 0 0.1 0.125 1.02626e-3 GW 18 15 0 0.35 0.125 0 0.11 0.25 1.02626e-3 GW 19 15 0 0.35 0.125 0 0.11 0 1.02626e-3 GW 20 2 0 0.37 -0.125 0 0.35 -0.125 1.02626e-3 GW 21 2 0 0.37 0.125 0 0.35 0.125 1.02626e-3 GW 22 7 0 0.37 -0.125 0 0.365 0 1.02626e-3 GW 23 7 0 0.365 0 0 0.37 0.125 1.02626e-3 GW 24 15 0 0.3313037 -0.3650552 0 0.11 -0.25 1.02626e-3 GW 25 15 0 0.3313037 0.36505518 0 0.11 0.25 1.02626e-3 GW 1 1 0 0.365 0 0 0.385 0 1.02626e-3 GW 1000 8 0 -0.546 -0.381 0 -0.688 -0.381 1.02626e-3 GW 1001 11 0 -0.546 -0.381 0 -0.419 -0.254 1.02626e-3 GW 1002 11 0 -0.546 0.381 0 -0.419 0.254 1.02626e-3 GW 1003 11 0 -0.419 -0.254 0 -0.546 -0.127 1.02626e-3 GW 1004 11 0 -0.419 0 0 -0.546 0.127 1.02626e-3 GW 1005 11 0 -0.546 0.127 0 -0.419 0.254 1.02626e-3 GW 1006 11 0 -0.419 0 0 -0.546 -0.127 1.02626e-3 GW 1007 8 0 -0.546 0.381 0 -0.688 0.381 1.02626e-3 GW 1008 5 0 -0.384 0 0 -0.419 0 1.02626e-3 GW 1009 8 0 -0.204 -0.381 0 -0.062 -0.381 1.02626e-3 GW 1010 11 0 -0.204 -0.381 0 -0.331 -0.254 1.02626e-3 GW 1011 11 0 -0.204 0.381 0 -0.331 0.254 1.02626e-3 GW 1012 11 0 -0.331 -0.254 0 -0.204 -0.127 1.02626e-3 GW 1013 11 0 -0.331 0 0 -0.204 0.127 1.02626e-3 GW 1014 11 0 -0.204 0.127 0 -0.331 0.254 1.02626e-3 GW 1015 11 0 -0.331 0 0 -0.204 -0.127 1.02626e-3 GW 1016 8 0 -0.204 0.381 0 -0.062 0.381 1.02626e-3 GW 1017 5 0 -0.366 0 0 -0.331 0 1.02626e-3 GW 1018 3 0 -0.384 0 0 -0.366 0 1.02626e-3 GE 0 EK EX 0 1 1 0 1 0 EX 0 1018 2 0 1 0 GN -1 FR 0 1 0 0 585 0 Last edited by stampeder; 2010-03-04 at 01:23 PM. Reason: added dimensions

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2010-01-21, 03:35 PM	#766
balm Veteran Join Date: Jan 2009 Location: Montreal Posts: 2,248	OTA, im trying several variations, but so far no go, all of them destroy the UHFs... the mast is not part of the modeling.

2010-01-21, 03:47 PM	#767
ota_canuck Veteran Join Date: Mar 2009 Location: Dunnville, Ontario on the Grand River, North shore Lake Erie Posts: 2,405	Maybe those Narods [being in character with traditional horizontal orientation of VHF antenna elements] can not be used in a bent 'V' form. If the Narods where placed behind the 9" horizontal elements perhaps or possibly just lengthen those 9" element to 14.5" elements.

2010-01-21, 11:23 PM	#770
balm Veteran Join Date: Jan 2009 Location: Montreal Posts: 2,248	nikiml, your AGT drops those numbers by 3-4 dbi, no?

2010-01-22, 06:31 PM	#773
ota_canuck Veteran Join Date: Mar 2009 Location: Dunnville, Ontario on the Grand River, North shore Lake Erie Posts: 2,405	bokakob, kudos,.. good job and a great antenna design performance comparison.

2010-01-22, 06:59 PM	#774
ota_canuck Veteran Join Date: Mar 2009 Location: Dunnville, Ontario on the Grand River, North shore Lake Erie Posts: 2,405	It appears that the centipede design focuses the horizontal forward gains rather than vertical gains. That could be good for some specific reception needs and bad for others who need to catch weaker overhead signals. Maybe I'm reading to much into this, but this probably means that overall antenna height is a bit more important for the centipede antenna design than it would be for the Hoverman design.

2010-01-22, 08:57 PM	#775
FranKllr Join Date: Sep 2009 Location: Shawinigan, QC Posts: 84	Including VHF-Hi gain from the Centipede serie would be nice.

2010-01-22, 10:20 PM	#779
bokakob Join Date: Aug 2009 Posts: 123	This looks good! I made the elements a bit longer to gain a bit of signal at the low end giving up some gain at the high end. It makes the curve more horizontal. Great work!

2010-01-23, 07:07 PM	#780
ota_canuck Veteran Join Date: Mar 2009 Location: Dunnville, Ontario on the Grand River, North shore Lake Erie Posts: 2,405	This is awsome. I was testing the centipede antenna design through out the past week. I did some experiments using a 29" NAROD to try to capture VHF. I have now abandoned my three 4bay antenna array and replaced it with just one Bi-directional centipede. The front of the antenna is aimed NNE toward Toronto and the back is toward Erie PA. Digital: 2.1/.2/.3 WGRZ Buffalo 100% 4.1 WIVB Buffalo 100% 5.1 CBC Toronto 100% 7.1 WKBW Buffalo 100% 9.1 CTV Toronto 60% 11.1 CHCH Hamilton 100% 12.1/.2/.2 Erie WICU/CW/WSEE 100% 15.1 SUN Hamilton 30% 17.1/.2/.3 WNED Buffalo 100% 23.1 CW Buffalo 80% 25 Toronto CBLTF 30% 26.1/.2 TCT Buffalo 100% 29.1/.2 Fox Buffalo 70% 35.1/.2 Erie WSEE/CW 100% 36.1 CTS Hamilton 100% 41.1 Global Toronto 20% 44.1 Omni-2 Toronto 40% 49.1/.2 MyTV Buffalo 80% 54.1/.2/.3 WQLN Erie 100% 57.1 CITY Toronto 15% 64.1 Omni[1] Toronto 15% 66.1 Fox 66 Erie 100% Analog: 5, 6, 9 ,11, 13, 19, 28, 31, 36, 45, 47, 55, 57