x-240 is very hard to get swr<3 at 174mhz but im stil trying with a gain of 11dbi
Area 51 for Antenna Modelers & Builders (See Post #1)
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!"
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!"
241 - 260 of 1328 Posts
Yeah, it does improve vhf-hi over my post 20 here: http://www.digitalhome.ca/forum/showthread.php?t=99907&page=2
But, it knocks the uhf gain curve for a loop, heh.
But, it knocks the uhf gain curve for a loop, heh.
dang 300ohms wish i would have seen your VHF_Hi before i started out and your pics now
i"ll see if NARODs can improve what you have done
Mite take me sometime but i like to play.
Now i have 2 models to go at thank you.
Well I'm working on the VHF_HI then I work on the SWR for the UHF that 473 looks to be fun
i"ll see if NARODs can improve what you have done
Mite take me sometime but i like to play.
Now i have 2 models to go at thank you.
Well I'm working on the VHF_HI then I work on the SWR for the UHF that 473 looks to be fun
Ramkats tophat NAROD gets rid of the dip in the uhf gain curve, and changes the SWR, but I havent modeled a vhf-hi general purpose version of it yet.
x-240 was lots of fun I now have the SWR <2 on VHF_HI with a gain of 9 to 10 dbi , UHF SWR <3 from 470 to 585 at time of 4Nec2 test. The gain is not that great in the UHF ,
I have not test colrods yet but i believe it may have to do with the 8 inch stubs for the gain in the UHF frequence.
But so far very pleased with the resaults .
To 300ohm's
Ramkats tophat NAROD i have not modeled yet but to use them they could be used on the top and bottom of the element layout the middle would not be needed ,I believe
I have not test colrods yet but i believe it may have to do with the 8 inch stubs for the gain in the UHF frequence.
But so far very pleased with the resaults .
To 300ohm's
Ramkats tophat NAROD i have not modeled yet but to use them they could be used on the top and bottom of the element layout the middle would not be needed ,I believe
Code:
CM 300ohms DBGH no reflector
CM 88mm feedgap
CM 10 gauge phasing line with 2 inch phasing line gap, 1 inch high
CM SWR <2 VHF_HI SWR <3 UHF edit by WildWillie
CM work in progress for higher gain in the UHF
CE
GW 30 5 0 1.65338786 -15.51916 0 6.65338786 -10.51916 0.06424494
GW 31 5 0 1.65338786 -5.5191602 0 6.65338786 -10.51916 0.06424494
GW 32 5 0 1.65338786 -5.5191602 0 6.65338786 -0.5191602 0.06424494
GW 34 5 0 -1.8111791 -15.51916 0 -6.8111791 -10.51916 0.06424494
GW 35 5 0 -1.8111791 -5.5191602 0 -6.8111791 -10.51916 0.06424494
GW 36 5 0 -1.8111791 -5.5191602 0 -6.8111791 -0.5191602 0.06424494
GW 38 5 0 1.65338786 -15.51916 0 6.65338786 -20.51916 0.06424494
GW 39 5 0 1.65338786 -25.51916 0 6.65338786 -20.51916 0.06424494
GW 40 5 0 1.65338786 -25.51916 0 6.65338786 -30.51916 0.06424494
GW 42 5 0 -1.8111791 -15.51916 0 -6.8111791 -20.51916 0.06424494
GW 43 5 0 -1.8111791 -25.51916 0 -6.8111791 -20.51916 0.06424494
GW 44 5 0 -1.8111791 -25.51916 0 -6.8111791 -30.51916 0.06424494
GW 46 7 0 6.65338786 0.48083979 0 14.8422063 0.49963777 0.06424494
GW 47 7 0 -6.8111791 0.48083979 0 -15 0.5 0.06424494
GW 55 5 0 -6.8111791 0.48083979 0 -1.8111791 5.48083979 0.06424494
GW 56 5 0 6.65338786 0.48083979 0 1.65338786 5.48083979 0.06424494
GW 57 5 0 -6.8111791 30.4808398 0 -1.8111791 25.4808398 0.06424494
GW 58 5 0 6.65338786 30.4808398 0 1.65338786 25.4808398 0.06424494
GW 61 5 0 -1.8111791 5.48083979 0 -6.8111791 10.4808398 0.06424494
GW 62 5 0 1.65338786 5.48083979 0 6.65338786 10.4808398 0.06424494
GW 66 5 0 1.65338786 15.4808398 0 6.65338786 20.4808398 0.06424494
GW 67 5 0 -6.8111791 20.4808398 0 -1.8111791 25.4808398 0.06424494
GW 68 5 0 6.65338786 20.4808398 0 1.65338786 25.4808398 0.06424494
GW 69 5 0 1.65338786 15.4808398 0 6.65338786 10.4808398 0.06424494
GW 100 7 0 6.65338786 30.4808398 0 14.9211044 30.4808398 0.06424494
GW 101 7 0 -6.8111791 30.4808398 0 -15.078896 30.4808398 0.06424494
GW 103 7 0 6.65338786 -0.5191602 0 14.8422063 -0.5003622 0.06424494
GW 104 7 0 -6.8111791 -0.5191602 0 -14.999997 -0.5 0.06424494
GW 106 7 0 6.65338786 -30.51916 0 14.9211044 -30.51916 0.06424494
GW 107 7 0 -6.8111791 -30.51916 0 -15.078896 -30.51916 0.06424494
GW 121 1 0 -1.8111791 -15.51916 1 -1.0788956 -15.51916 0.0511811
GW 127 5 0 -6.8111791 20.4808398 0 -1.8111791 15.4808398 0.06424494
GW 128 5 0 -6.8111791 10.4808398 0 -1.8111791 15.4808398 0.06424494
GW 129 1 0 -1.8111791 15.4808398 1 -1.0788956 15.4808398 0.0511811
GW 110 1 0 1.65338786 -15.51916 1 0.9211044 -15.51916 0.0511811
GW 130 11 1 -1.0788956 15.4808398 1 -1.0788956 -0.0191602 0.0511811
GW 131 1 0 1.65338786 15.4808398 1 0.9211044 15.4808398 0.0511811
GW 132 11 1 0.9211044 15.4808398 1 0.9211044 -0.0191602 0.0511811
GW 133 11 1 -1.0788956 -0.0191602 1 -1.0788956 -15.51916 0.0511811
GW 134 11 1 0.9211044 -0.0191602 1 0.9211044 -15.51916 0.0511811
GW 135 1 1 -1.0788956 -0.0191602 1 0.9211044 -0.0191602 0.077
GW 137 23 0 -15.105524 0.01991814 0 14.8944768 0.01991814 0.16243037
GW 138 23 0 -16.367851 -31.26916 0 15.3821497 -31.26916 0.16243037
GW 139 9 0 -5.136885 29.6617992 0 5.48145952 29.6617992 0.16243037
GW 140 9 0 -5.4524661 -29.817157 0 5.16587802 -29.817157 0.16243037
GW 141 9 0 -4.8213023 20.2028839 0 5.7970418 20.2028839 0.16243037
GW 142 9 0 -4.9790928 -20.678878 0 5.63925125 -20.678878 0.16243037
GW 143 5 0 -3.5589743 10.4233256 0 3.90355086 10.4233256 0.16243037
GW 144 5 0 -3.7167649 -10.57868 0 3.7457607 -10.57868 0.16243037
GW 145 25 -10 -16.71006 31 -10 16.3022669 31 0.16243037
GW 146 25 -10 -16.77564 -29.869738 -10 16.2366858 -29.869738 0.1624304
GW 147 27 -10 -19.44576 0.4604224 -10 17.566537 0.4604224 0.1624304
GW 148 23 0 -16.024458 31.1524063 0 15.7255422 31.1524063 0.16243037
GW 149 21 -10 -14.525443 38.9208413 -10 13.910948 38.9208413 0.16243037
GW 150 21 -10 -13.973176 -38.107615 -10 14.463215 -38.107615 0.16243037
GW 151 23 -10 -16.02447 -31.592988 -10 16.041126 -31.592988 0.1624304
GW 152 23 -10 -16.024476 32.9701405 -10 16.041124 32.9701405 0.16243037
GW 153 23 -10 -15.55109 34.8939854 -10 15.514515 34.8939854 0.1624304
GW 154 23 -10 -15.55109 -34.639078 -10 15.514515 -34.639078 0.1624304
GW 155 23 -10 -15.10335 36.8178393 -10 14.9622461 36.8178393 0.1624304
GW 156 23 -10 -14.60434 -36.402605 -10 15.4612602 -36.402605 0.16243037
GW 157 9 -5.55 -5.8683429 16 -5.55 6 16 0.1624304
GW 158 9 -5.55 -6 15 -5.55 5.86834252 15 0.1624304
GW 159 9 -5.55 -6 -14 -5.55 5.86834331 -14 0.1624304
GW 160 9 -5.55 -6 -16 -5.55 5.8683437 -16 0.1624304
GW 161 13 -5.55 -8.391 22 -5.55 8 22 0.1624304
GW 162 13 -5.55 -8 8 -5.55 9.391 8 0.1624304
GW 163 13 -5.55 -8 -8 -5.55 9.391 -8 0.1624304
GW 164 13 -5.55 -8.391 -23 -5.55 8 -23 0.1624304
GW 165 11 -5.55 -7.4916 19 -5.55 7 19 0.1624304
GW 166 9 -5.55 -6 13 -5.55 6.916 13 0.1624304
GW 167 9 -5.55 -6 -12 -5.55 6.4916 -12 0.1624304
GW 168 11 -5.55 -7.916 -19 -5.55 7 -19 0.1624304
GW 169 13 -5.55 -9 17 -5.55 8.916 17 0.1624304
GW 170 9 -5.55 -6 12 -5.55 6.4916 12 0.1624304
GW 171 9 -5.55 -6.916 -11 -5.55 6 -11 0.1624304
GW 172 13 -5.55 -9 -18 -5.55 8.4916 -18 0.1624304
GW 173 27 -10 -19 12 -10 18.012297 12 0.1624304
GW 174 27 -10 -19 -12 -10 18.012297 -12 0.1624304
GW 175 27 -10 -19 4 -10 18.012297 4 0.1624304
GW 176 27 -10 -19 -3 -10 18.012297 -3 0.1624304
GS 0 0 0.0254 ' All in in.
GE 0
EK
LD 5 0 0 0 3.77e7 0
EX 0 135 1 0 1 0
GN -1
FR 0 1 0 0 170 0
RP 0 1 10 1510 90. 0. 0. 20. 0. 0.75 ohm direct-connect Hoverman-like antenna for UHF-lo
Hi,
Here is a design for a 75 ohm-direct connect Hoverman-like antenna.
Because the bandwidth is limited, it optimized it for 475-600 MHz.
Later I will post a model for the higher frequencies.
The net gain peaks at about 15.6 dBi near 550 MHz. Because no
matching transformer is required, there is no loss associated with
one. Although it is a direct-connect antenna, a careful person would
attach the coax through a 1-1 balun to avoid feedline currents. But
such baluns are not easy to come by and at these frequencies, could
limit the bandwidth. If it were me, I would forego the balun.
The dGain column in the table below represents the difference between
the NetGain and RawGain columns, and reflects the mismatch loss
between the coax and the antenna. The NetGain has been AGT corrected.
Here is the NEC file:
--John
Hi,
Here is a design for a 75 ohm-direct connect Hoverman-like antenna.
Because the bandwidth is limited, it optimized it for 475-600 MHz.
Later I will post a model for the higher frequencies.
The net gain peaks at about 15.6 dBi near 550 MHz. Because no
matching transformer is required, there is no loss associated with
one. Although it is a direct-connect antenna, a careful person would
attach the coax through a 1-1 balun to avoid feedline currents. But
such baluns are not easy to come by and at these frequencies, could
limit the bandwidth. If it were me, I would forego the balun.
The dGain column in the table below represents the difference between
the NetGain and RawGain columns, and reflects the mismatch loss
between the coax and the antenna. The NetGain has been AGT corrected.
Code:
freq[MHz] SWR RawGain NetGain dGain F/B
471.25 3.73766 14.71 12.9453 -1.76468 9.11
477.25 3.1019 14.8893 13.5665 -1.32283 9.21
483.25 2.62622 15.0583 14.0831 -0.975173 9.33
489.25 2.29346 15.2269 14.4994 -0.727536 9.5
495.25 2.08988 15.3854 14.8083 -0.577022 9.7
501.25 1.99922 15.5338 15.0228 -0.510963 9.93
507.25 1.99592 15.6724 15.1638 -0.508575 10.2
513.25 2.04538 15.8013 15.2568 -0.544489 10.51
519.25 2.11114 15.9109 15.3183 -0.592623 10.86
525.25 2.16111 15.9915 15.3621 -0.629427 11.23
531.25 2.17052 16.0432 15.4068 -0.636372 11.64
537.25 2.12363 16.0561 15.4543 -0.601806 12.07
543.25 2.01527 16.0303 15.5077 -0.52259 12.53
549.25 1.85103 15.9655 15.5602 -0.405303 13.02
555.25 1.64573 15.8715 15.6047 -0.266725 13.52
561.25 1.4196 15.7278 15.5952 -0.132611 14.01
567.25 1.19364 15.554 15.52 -0.0339743 14.47
573.25 1.0218 15.3299 15.3294 -0.00050478 14.85
579.25 1.24655 15.0753 15.0226 -0.0526255 15.13
585.25 1.53094 14.78 14.5846 -0.195456 15.27
591.25 1.87293 14.4641 14.0434 -0.420688 15.14
597.25 2.30236 13.8344 13.1002 -0.734156 13.53
Code:
CM Model: DC-8-UHFlo
CE
GW 1 19 0.101018 -0.0392186 0 0.101018 0.0392186 0 0.00205769
GW 2 19 0.101018 -0.0392186 0 0.0591873 -0.113347 0 0.00205769
GW 3 19 0.101018 0.0392186 0 0.0591873 0.113347 0 0.00205769
GW 4 25 0.101018 -0.0392186 0 0 -0.0127103 0 0.00205769
GW 5 25 0.101018 0.0392186 0 0 0.0127103 0 0.00205769
GW 6 103 0 -0.0127103 0 0 -0.344589 0.274073 0.00205769
GW 7 103 0 -0.0127103 0 0 -0.344589 -0.274073 0.00205769
GW 8 103 0 0.0127103 0 0 0.344589 0.274073 0.00205769
GW 9 103 0 0.0127103 0 0 0.344589 -0.274073 0.00205769
GW 10 59 0 -0.344589 0.274073 0 -0.153102 0.432208 0.00205769
GW 11 59 0 -0.344589 -0.274073 0 -0.153102 -0.432208 0.00205769
GW 12 59 0 0.344589 0.274073 0 0.153102 0.432208 0.00205769
GW 13 59 0 0.344589 -0.274073 0 0.153102 -0.432208 0.00205769
GW 14 45 0 -0.153102 0.432208 0 -0.29621 0.55039 0.00205769
GW 15 45 0 -0.153102 -0.432208 0 -0.29621 -0.55039 0.00205769
GW 16 45 0 0.153102 0.432208 0 0.29621 0.55039 0.00205769
GW 17 45 0 0.153102 -0.432208 0 0.29621 -0.55039 0.00205769
GW 18 23 0 -0.29621 0.55039 0 -0.397516 0.55039 0.00205769
GW 19 23 0 -0.29621 -0.55039 0 -0.397516 -0.55039 0.00205769
GW 20 23 0 0.29621 0.55039 0 0.397516 0.55039 0.00205769
GW 21 23 0 0.29621 -0.55039 0 0.397516 -0.55039 0.00205769
GW 22 87 -0.0867753 -0.6096 -0.544908 -0.0867753 0 -0.544908 0.0035
GW 23 87 -0.0867753 0 -0.544908 -0.0867753 0.6096 -0.544908 0.0035
GW 24 87 -0.0867753 -0.6096 -0.413654 -0.0867753 0 -0.413654 0.0035
GW 25 87 -0.0867753 0 -0.413654 -0.0867753 0.6096 -0.413654 0.0035
GW 26 87 -0.0867753 -0.6096 -0.267001 -0.0867753 0 -0.267001 0.0035
GW 27 87 -0.0867753 0 -0.267001 -0.0867753 0.6096 -0.267001 0.0035
GW 28 67 -0.0867753 -0.476333 -0.0984601 -0.0867753 0 -0.0984601 0.0035
GW 29 67 -0.0867753 0 -0.0984601 -0.0867753 0.476333 -0.0984601 0.0035
GW 30 67 -0.0867753 -0.476333 0.0984601 -0.0867753 0 0.0984601 0.0035
GW 31 67 -0.0867753 0 0.0984601 -0.0867753 0.476333 0.0984601 0.0035
GW 32 87 -0.0867753 -0.6096 0.267001 -0.0867753 0 0.267001 0.0035
GW 33 87 -0.0867753 0 0.267001 -0.0867753 0.6096 0.267001 0.0035
GW 34 87 -0.0867753 -0.6096 0.413654 -0.0867753 0 0.413654 0.0035
GW 35 87 -0.0867753 0 0.413654 -0.0867753 0.6096 0.413654 0.0035
GW 36 87 -0.0867753 -0.6096 0.544908 -0.0867753 0 0.544908 0.0035
GW 37 87 -0.0867753 0 0.544908 -0.0867753 0.6096 0.544908 0.0035
GE 0
EK 0
FR 0 39 0 0 471.25 6
EX 0 1 10 0 1
GN -1 0 0 0 0.0 0.0 0.0 0.0 0.0 0.0
RP 0 60 73 1001 0 0 3 5
ENMy recent builds of wifi biquad antennas without baluns, while still good, leads me to believe that there is a very significant penalty to be paid without a balun to go from a balanced antenna to the unbalanced coax, thats not reflected in the net gain calculation.Although it is a direct-connect antenna, a careful person would
attach the coax through a 1-1 balun to avoid feedline currents. But
such baluns are not easy to come by and at these frequencies, could
limit the bandwidth. If it were me, I would forego the balun.
Of course, I have no test equipment. I have to judge comparing a 2dbi (stated) Rosewill rubber ducky antenna which is connected up with a meter of RG174U coax, which easily knocks a dbi off, leaving about 1dbi at the wifi card input, heh. And in Ubuntu, I use RutiL for the signal measurement.
My biquads, per modeling, should be about 10 to 11 dbi. They are connected up with 2 meters of RG58U coax, also a loss of about a dbi, but better than RG174U. My builds are pretty exacting, I would say within .5mm. (Will post pictures of latest build later) But, all in all, Im not seeing the 9 dbi difference in gain I should. I think a good portion of that may be due to a lack of balun.
I imagine that those building these high-gain antennas are using aMy recent builds of wifi biquad antennas without
baluns, while still good, leads me to believe that there is a very
significant penalty to be paid without a balun to go from a balanced
antenna to the unbalanced coax, thats not reflected in the net gain
calculation.
preamp. It seems to me that much of the feedline radiation could be
choked off by properly choosing the length of cable connecting the
antenna to the preamp. Also the coax should drop vertically from the
feed point and be properly centered.
Have you tried playing with the length of the coax?My biquads, per modeling, should be about 10 to
11 dbi. They are connected up with 2 meters of RG58U coax, also a loss
of about a dbi, but better than RG174U. My builds are pretty exacting,
I would say within .5mm. (Will post pictures of latest build later)
But, all in all, Im not seeing the 9 dbi difference in gain I should.
I think a good portion of that may be due to a lack of balun.
Also, how confident are you in the accuracy of NEC-2 at such
frequencies?
Thanks,
--John
John: What is the stuff in the +X? The first part could be a 1/4 wave matching section, but what are the tails(another 1/4 wave stub)?
Not yet, but I was thinking the same thing. Maybe some air loops or loops around a ferrite core. Not as easy as aluminum foil around twinlead, heh.Have you tried playing with the length of the coax?
For the 2.4Ghz biquad style antenna, pretty confident. (other styles/types like the slotted waveguides or patch antenna types, NEC2 isnt that good on)Also, how confident are you in the accuracy of NEC-2 at such
frequencies?
Others have done some pretty good analysis on the Trevor Marshall 2.4Ghz biquad too. http://www.lecad.uni-lj.si/~leon/other/wlan/biquad/
I followed those guidelines on my last build.
Whiskers? I added them in an attempt to increase the bandwidth. TheyJohn: What is the stuff in the +X? The first part
could be a 1/4 wave matching section, but what are the tails(another
1/4 wave stub)?
also seemed to help the gain a bit. --John
direct-connect Hoverman-like design for UHF-hi
As promised, here is a 75 ohm design optimized for the 600-700 MHz
band. Ideally, it should be used with a 1-1 balun (see the earlier
discussion). The netgain near 16 dBi over much of the band.
Here is the NEC file:
Thanks,
--John
As promised, here is a 75 ohm design optimized for the 600-700 MHz
band. Ideally, it should be used with a 1-1 balun (see the earlier
discussion). The netgain near 16 dBi over much of the band.
Code:
freq[MHz] SWR RawGain NetGain dGain F/B
597.25 2.29267 15.5086 14.7817 -0.726948 8.96
603.25 2.05005 15.2912 14.7433 -0.547893 10.16
609.25 2.08993 15.6546 15.0775 -0.577057 8.48
615.25 1.70381 16.1806 15.8758 -0.304714 7.99
621.25 1.54366 16.3003 16.0973 -0.203063 8.26
627.25 1.51274 16.3601 16.1754 -0.184706 8.59
633.25 1.55366 16.41 16.2009 -0.209104 8.97
639.25 1.61952 16.4404 16.1904 -0.249972 9.38
645.25 1.67786 16.4417 16.1541 -0.287597 9.8
651.25 1.70855 16.4242 16.1163 -0.307862 10.26
657.25 1.70052 16.3781 16.0756 -0.30253 10.74
663.25 1.65007 16.3034 16.0339 -0.269526 11.25
669.25 1.56028 16.1899 15.9768 -0.213122 11.77
675.25 1.43962 16.0474 15.904 -0.143366 12.31
681.25 1.30052 15.8653 15.7906 -0.0747478 12.86
687.25 1.16002 15.6534 15.6295 -0.0239009 13.4
693.25 1.08157 15.4212 15.4145 -0.00667341 13.92
699.25 1.19755 15.1584 15.1231 -0.0352388 14.41
Code:
CM Model: DC-8-UHFhi
CE
GW 1 13 0.0790197 -0.0307354 0 0.0790197 0.0307354 0 0.00205769
GW 2 17 0.0790197 -0.0307354 0 0.0460475 -0.0944725 0 0.00205769
GW 3 17 0.0790197 0.0307354 0 0.0460475 0.0944725 0 0.00205769
GW 4 19 0.0790197 -0.0307354 0 0 -0.0127175 0 0.00205769
GW 5 19 0.0790197 0.0307354 0 0 0.0127175 0 0.00205769
GW 6 89 0 -0.0127175 0 0 -0.303555 0.228222 0.00205769
GW 7 89 0 -0.0127175 0 0 -0.303555 -0.228222 0.00205769
GW 8 89 0 0.0127175 0 0 0.303555 0.228222 0.00205769
GW 9 89 0 0.0127175 0 0 0.303555 -0.228222 0.00205769
GW 10 45 0 -0.303555 0.228222 0 -0.151483 0.347555 0.00205769
GW 11 45 0 -0.303555 -0.228222 0 -0.151483 -0.347555 0.00205769
GW 12 45 0 0.303555 0.228222 0 0.151483 0.347555 0.00205769
GW 13 45 0 0.303555 -0.228222 0 0.151483 -0.347555 0.00205769
GW 14 37 0 -0.151483 0.347555 0 -0.271706 0.441894 0.00205769
GW 15 37 0 -0.151483 -0.347555 0 -0.271706 -0.441894 0.00205769
GW 16 37 0 0.151483 0.347555 0 0.271706 0.441894 0.00205769
GW 17 37 0 0.151483 -0.347555 0 0.271706 -0.441894 0.00205769
GW 18 15 0 -0.271706 0.441894 0 -0.341595 0.441894 0.00205769
GW 19 15 0 -0.271706 -0.441894 0 -0.341595 -0.441894 0.00205769
GW 20 15 0 0.271706 0.441894 0 0.341595 0.441894 0.00205769
GW 21 15 0 0.271706 -0.441894 0 0.341595 -0.441894 0.00205769
GW 22 85 -0.0635445 -0.597882 -0.450593 -0.0635445 0 -0.450593 0.0035
GW 23 85 -0.0635445 0 -0.450593 -0.0635445 0.597882 -0.450593 0.0035
GW 24 87 -0.0635445 -0.6096 -0.374587 -0.0635445 0 -0.374587 0.0035
GW 25 87 -0.0635445 0 -0.374587 -0.0635445 0.6096 -0.374587 0.0035
GW 26 83 -0.0635445 -0.592336 -0.257565 -0.0635445 0 -0.257565 0.0035
GW 27 83 -0.0635445 0 -0.257565 -0.0635445 0.592336 -0.257565 0.0035
GW 28 51 -0.0635445 -0.366453 -0.0995267 -0.0635445 0 -0.0995267 0.0035
GW 29 51 -0.0635445 0 -0.0995267 -0.0635445 0.366453 -0.0995267 0.0035
GW 30 51 -0.0635445 -0.366453 0.0995267 -0.0635445 0 0.0995267 0.0035
GW 31 51 -0.0635445 0 0.0995267 -0.0635445 0.366453 0.0995267 0.0035
GW 32 83 -0.0635445 -0.592336 0.257565 -0.0635445 0 0.257565 0.0035
GW 33 83 -0.0635445 0 0.257565 -0.0635445 0.592336 0.257565 0.0035
GW 34 87 -0.0635445 -0.6096 0.374587 -0.0635445 0 0.374587 0.0035
GW 35 87 -0.0635445 0 0.374587 -0.0635445 0.6096 0.374587 0.0035
GW 36 85 -0.0635445 -0.597882 0.450593 -0.0635445 0 0.450593 0.0035
GW 37 85 -0.0635445 0 0.450593 -0.0635445 0.597882 0.450593 0.0035
GE 0
EK 0
FR 0 39 0 0 471.25 6
EX 0 1 7 0 1
GN -1 0 0 0 0.0 0.0 0.0 0.0 0.0 0.0
RP 0 60 73 1001 0 0 3 5
EN--John
Vertical Bi-Quad
Hello everyone, recently I made an antenna from a thick copper electrical wire. It is vertically oriented in “double bi-quad” shape with 120 mm between center lines of each square side. There is a reflector located behind the antenna. This reflector is made of pretty dense galvanized mesh 10mm x 10mm. The distance is 67 mm from the center line of the antenna to the mesh. The antenna feed is connected with 4:1 balun in the middle made of RG-59 TV-cable. It works exceptionally well and pulls in just under 20 stations. I can not evaluate this antenna and ask for help if someone with proper knowledge would run this setup through any digital simulation program. Any help is appreciated -- thanks.
Hello everyone, recently I made an antenna from a thick copper electrical wire. It is vertically oriented in “double bi-quad” shape with 120 mm between center lines of each square side. There is a reflector located behind the antenna. This reflector is made of pretty dense galvanized mesh 10mm x 10mm. The distance is 67 mm from the center line of the antenna to the mesh. The antenna feed is connected with 4:1 balun in the middle made of RG-59 TV-cable. It works exceptionally well and pulls in just under 20 stations. I can not evaluate this antenna and ask for help if someone with proper knowledge would run this setup through any digital simulation program. Any help is appreciated -- thanks.
Basically, a biquad with solid reflector produces about 10 to 11 dbi in gain, with a nice wide round pattern. A double biquad, about 13 dbi, but if all quads are the same, the bandwidth is low. Look here, post 32 and 34, for a wide band double biquad type : http://www.digitalhome.ca/forum/showthread.php?t=105660&page=3
Bob
what instructions were you building from that says to connect a 4:1 balun to the feed point of a “double bi-quad” ???
what instructions were you building from that says to connect a 4:1 balun to the feed point of a “double bi-quad” ???
Interesting. With the stubs so short, NARODs have little effect of lowering VHF-Hi SWR on X0252.
Thank you for pointing me in the right direction. Could anyone help me to evaluate this antenna? Thanks
http://www.digitalhome.ca/forum/album.php?albumid=298&pictureid=1345
http://www.digitalhome.ca/forum/album.php?albumid=298&pictureid=1345
bokakakob: I have looked at some thing all most the same 135 (94) 175 (170) 130 (142) feed gap 50 (41).With out a reflector raw gain of [email protected] Ch14 up to 8.7 @Ch40 and to 7.5 @Ch51. With a reflector 10.8,11.6,9.8. I'm on a road trip. I will look at your dim. in a day or two.
It will be similiar to this one, posts 11 and 14 : http://www.digitalhome.ca/forum/showthread.php?t=105660
Xauto built one. Looks very easy to do.
Xauto built one. Looks very easy to do.
bokakob: Your design would be good for Ch. 14 to 69. Raw gain is [email protected] Ch.14 then peaks at [email protected] and [email protected] The SWR is [email protected] then to [email protected] then [email protected] and [email protected] Hope that helped.
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