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Hello all, I have read a lot on these forums and others about TV antennas and looked at the specs (computer models) of many of them. It seems like the two most popular for diy building is either some form of bowtie or gray hoverman design. I chose to build one of holl-ands models to test that doesn't seem to get any attention but I feel is a hidden gem. The model I am chatting about is his H+U 4-Bay Loop RLH4 - No Refl. It is a connected bowtie that is almost like a gray hoverman or zig-zag, but not, with a non connected high vhf loop. It has decent UHF gain and the High VHF gain is almost double of most of the bowtie or gray hoverman designs without reflector. It has good SWR on both UHF and High VHF. I understand every persons results will vary with location / environmental conditions for their location for which antenna is best for them.

Have any of you built this antenna?
I am curious how it compares with a 4 bay bowtie or a gray hoverman design. I wish I had more time to build one of each but I just don't have the time right now.

The following info is just describing what channels I was trying to get and why this particular antenna works for me. The one I built is only on a 17ft pole right now and a get a lot of channels in solid no mater the weather conditions. I live in alexandria indiana and am receiving all the Indianapolis channels and muncie indiana channels. The muncie channel is 18 miles from me and i get it off the side (90 degrees) of the antenna no problems. My antenna is facing the indanapolis channels which are any where from 32 miles to 38 miles from me line of sight (mostly UHF but also some are High VHF). I know that this is not that far of a distance compared to trying to get channels in longer range but I feel this antenna is very well suited for this distance. I also wanted an antenna that could receive from two directions because I am wanting to get marion indiana channels which are about 20 miles from me but is extremely low powered stations. The marion stations are pretty much 180 degrees from Indianapolis stations from me. I did receive one of the two marion stations one day but not reliable yet because I have a lot of trees in that direction and once I get my tv tower up so I can get my antenna up much higher and above the trees I feel like i will get them also with just the one antenna and without having to re-aim it hence why no reflector design. I have also received but not steady by any means some of the bloomington indiana channels which is in the Indianapolis direction just much farther away at around 60 miles. The same with fortwayne channels which is in the marion direction but again about 60 miles out. And strangely I occasionally received one lafayette indiana channel off the side (90 degrees) of the antenna that is a good distance from me but again not reliably.
 

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Discussion Starter #2
Hello all, I have read a lot on these forums and others about TV antennas and looked at the specs (computer models) of many of them. It seems like the two most popular for diy building is either some form of bowtie or gray hoverman design. I chose to build one of holl-ands models to test that doesn't seem to get any attention but I feel is a hidden gem. The model I am chatting about is his H+U 4-Bay Loop RLH4 - No Refl. It is a connected bowtie that is almost like a gray hoverman or zig-zag, but not, with a non connected high vhf loop. It has decent UHF gain and the High VHF gain is almost double of most of the bowtie or gray hoverman designs without reflector. It has good SWR on both UHF and High VHF. I understand every persons results will vary with location / environmental conditions for their location for which antenna is best for them.

Have any of you built this antenna?
I am curious how it compares with a 4 bay bowtie or a gray hoverman design. I wish I had more time to build one of each but I just don't have the time right now.

The following info is just describing what channels I was trying to get and why this particular antenna works for me. The one I built is only on a 17ft pole right now and a get a lot of channels in solid no mater the weather conditions. I live in alexandria indiana and am receiving all the Indianapolis channels and muncie indiana channels. The muncie channel is 18 miles from me and i get it off the side (90 degrees) of the antenna no problems. My antenna is facing the indanapolis channels which are any where from 32 miles to 38 miles from me line of sight (mostly UHF but also some are High VHF). I know that this is not that far of a distance compared to trying to get channels in longer range but I feel this antenna is very well suited for this distance. I also wanted an antenna that could receive from two directions because I am wanting to get marion indiana channels which are about 20 miles from me but is extremely low powered stations. The marion stations are pretty much 180 degrees from Indianapolis stations from me. I did receive one of the two marion stations one day but not reliable yet because I have a lot of trees in that direction and once I get my tv tower up so I can get my antenna up much higher and above the trees I feel like i will get them also with just the one antenna and without having to re-aim it hence why no reflector design. I have also received but not steady by any means some of the bloomington indiana channels which is in the Indianapolis direction just much farther away at around 60 miles. The same with fortwayne channels which is in the marion direction but again about 60 miles out. And strangely I occasionally received one lafayette indiana channel off the side (90 degrees) of the antenna that is a good distance from me but again not reliably.
Here is a photo of the antenna I built. This photo is not the finished version but during initial tests. The balun and the way the antenna mounts to the pole is not finished in this photo.
11821
 

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I downloaded/copied Holl_ands H+U 4-Bay Loop RLH4 - No Refl design and modeled it with 4nec2. It resulted in errors, caused by intersecting wires, where the top and bottom element fold back together. When forced to run, the results are similar to those listed. When I changed the model, so the the elements (tag 11, 13, 15, 17) both used "Z7" as the Z coordinate, the model runs without error. This change causes a considerable increase in the swr, in the Hi-VHF range. Using the original model, and changing the time separation to 8.5 separates the tines, creating a traditional 4 bay design, and lowers the SWR, in the Hi-VHF range, back below 2.7. This indicates to me that the design will work better if the upper and lower bays are separated, and the design is changed to a traditional 4 bay design. I've done some modeling of a similar design that uses a simpler loop design, using a single loop around all 4 bays and optimized it for the new repack frequency range. It also uses the 1/2" copper plumbing pipe for the loop. Model uses 1/4" copper tubing for the whiskers, but works well with smaller diameter wire as well.

Code:
CM Based on Kosmic SuperQuad 4-Bay, NO Reflector, 4nec2 by holl_ands, 1Mar2010
CM Reshaped to work better with US Repack.
CM Bowties increased to 1/4" Copper tubing.
CM Good UHF numbers with very usable HiVHF.
CM HiVHF can be improved with a 1/2" copper pipe loop, and reflectors can be added.
CM Simple SOURCE Wire. Modeled without Autoseg.
CM Source wire sized to 0.029 will be close enough to model HiVHF and UHF together.
CE
SY Scale=1.0
SY sc=Scale
SY Rsrc=0.029    'SOURCE wire Radius. Adjust for AGT=1.0:           UHF(540)=0.038  &   HiVHF(198)=0.020          No AutoSeg
SY Rbow=0.125    'Radius (in inches) of BOWTIE elements    1/4" tubing
SY Rfeed=0.0642    'FEEDLINE wire Radius   #8 wire
SY Rloop=0.3125    '0.3125       1/2" copper tubing (5/8"od)
SY Rrefl=0.125    '0.125         1/4" rods    SWR slightly better with 1/2" tubing
SY ZBowII=12.0    'Distance between the Centers of the two INNER bowties    12.0
SY ZBowOI=ZBowII    'From Center of INNER bowtie to Center of OUTER bowtie
SY BowLen=11.0    'Bow Half-Length - Assume all SAME (Reality +/- 0.25+ in)     11.0
SY BowSep=5.0    'Bow Tine Separation - Assume all SAME (Reality +/- 0.25 in)
SY FedSep=0.75    'Separation (in inches) between two FEEDLINE wires    0.75
SY Hop=FedSep    'Separation between Feedlines at Crossover                       Same as FedSep to work with PVC center support.
SY ZCross=6.0    'From Center of Feedline Crossover to Center of OUTER bowtie    5.58
SY ZClen=4.0    'From Center of Feedline Crossover to Inflection point    4.6
SY Cond=3.0e7    'Conductivity (Copper=3.0e7, Alum=2.0e7, StainlessSteel=1.67e7)
SY LoophighDelta=6.0    '5.0     7.25 better for UHF
SY LoopwideDelta=0.5625    '.4375  1/8" gap              0.5625 for 1/4" gap      0.44215 to normalize length
SY Reflector0=36    'Length of center reflectors       49.5              48" is very close and cheaper.      36 is OK
SY Reflector1=Reflector0    'Length of first reflectors
SY Reflector2=Reflector0    'Length of second reflectors
SY Reflector3=Reflector0    'Length of third reflectors
SY Reflector4=Reflector0    'Length of fourth reflectors
SY Rdback=16.0    '15.8125        16.0
SY ZBowInr=ZBowII/2    'Distance from antenna center to center of INNER bowtie
SY ZBowOut=ZBowII/2+ZBowOI    'Distance from antenna center to center of OUTER bowtie
SY Z1=ZBowOut+BowSep/2
SY Z2=ZBowOut
SY Z3=ZBowOut-BowSep/2
SY Z4=ZBowOut-ZCross+ZClen    'Very long crossover region
SY Z5=ZBowOut-ZCross
SY Z6=ZBowOut-ZCross-ZClen    'Very long crossover region
SY Z7=ZBowInr+BowSep/2
SY Z8=ZBowInr
SY Z9=ZBowInr-BowSep/2
SY Z10=(Z2+Z8)/2
SY Z11=Z8*4
SY YBowN=-FedSep/2
SY YBowP=FedSep/2
SY YBow=(BowLen^2-(BowSep/2)^2)^0.5
SY Ymax=YBow+FedSep/2
SY Loophigh=Z1+LoophighDelta
SY Lh=Loophigh
SY Loopwide=Ymax+Loopwidedelta
SY Lw=Loopwide
SY R0Ypos=Reflector0/2
SY R1Ypos=Reflector1/2
SY R2Ypos=Reflector2/2
SY R3Ypos=Reflector3/2
SY R4Ypos=Reflector4/2
GW    1    1    0    YBowN*sc    0    0    YBowP*sc    0    Rsrc
GW    4    7    0    Ymax*sc    Z7*sc    0    YBowP*sc    Z8*sc    Rbow
GW    5    7    0    Ymax*sc    Z9*sc    0    YBowP*sc    Z8*sc    Rbow
GW    6    7    0    YBowN*sc    Z8*sc    0    -Ymax*sc    Z7*sc    Rbow
GW    7    7    0    YBowN*sc    Z8*sc    0    -Ymax*sc    Z9*sc    Rbow
GW    8    7    0    Ymax*sc    -Z7*sc    0    YBowP*sc    -Z8*sc    Rbow
GW    9    7    0    Ymax*sc    -Z9*sc    0    YBowP*sc    -Z8*sc    Rbow
GW    10    7    0    YBowN*sc    -Z8*sc    0    -Ymax*sc    -Z7*sc    Rbow
GW    11    7    0    YBowN*sc    -Z8*sc    0    -Ymax*sc    -Z9*sc    Rbow
GW    12    7    0    Ymax*sc    Z1*sc    0    YBowP*sc    Z2*sc    Rbow
GW    13    7    0    Ymax*sc    Z3*sc    0    YBowP*sc    Z2*sc    Rbow
GW    14    7    0    YBowN*sc    Z2*sc    0    -Ymax*sc    Z1*sc    Rbow
GW    15    7    0    YBowN*sc    Z2*sc    0    -Ymax*sc    Z3*sc    Rbow
GW    16    7    0    Ymax*sc    -Z1*sc    0    YBowP*sc    -Z2*sc    Rbow
GW    17    7    0    Ymax*sc    -Z3*sc    0    YBowP*sc    -Z2*sc    Rbow
GW    18    7    0    YBowN*sc    -Z2*sc    0    -Ymax*sc    -Z1*sc    Rbow
GW    19    5    0    YBowN*sc    -Z2*sc    0    -Ymax*sc    -Z3*sc    Rbow
GW    20    1    0    YBowP*sc    Z2*sc    0    YBowP*sc    Z4*sc    Rfeed
GW    21    1    0    YBowN*sc    Z2*sc    0    YBowN*sc    Z4*sc    Rfeed
GW    22    1    0    YBowP*sc    Z6*sc    0    YBowP*sc    Z8*sc    Rfeed
GW    23    1    0    YBowN*sc    Z6*sc    0    YBowN*sc    Z8*sc    Rfeed
GW    24    3    0    YBowN*sc    Z6*sc    (Hop/2)*sc    0    Z5*sc    Rfeed
GW    25    3    0    YBowP*sc    Z4*sc    (Hop/2)*sc    0    Z5*sc    Rfeed
GW    26    3    0    YBowP*sc    Z6*sc    (-Hop/2)*sc    0    Z5*sc    Rfeed
GW    27    3    0    YBowN*sc    Z4*sc    (-Hop/2)*sc    0    Z5*sc    Rfeed
GW    28    1    0    YBowP*sc    -Z2*sc    0    YBowP*sc    -Z4*sc    Rfeed
GW    29    1    0    YBowN*sc    -Z2*sc    0    YBowN*sc    -Z4*sc    Rfeed
GW    30    1    0    YBowP*sc    -Z6*sc    0    YBowP*sc    -Z8*sc    Rfeed
GW    31    1    0    YBowN*sc    -Z6*sc    0    YBowN*sc    -Z8*sc    Rfeed
GW    32    3    0    YBowN*sc    -Z6*sc    (-Hop/2)*sc    0    -Z5*sc    Rfeed
GW    33    3    0    YBowP*sc    -Z4*sc    (-Hop/2)*sc    0    -Z5*sc    Rfeed
GW    34    3    0    YBowP*sc    -Z6*sc    (Hop/2)*sc    0    -Z5*sc    Rfeed
GW    35    3    0    YBowN*sc    -Z4*sc    (Hop/2)*sc    0    -Z5*sc    Rfeed
GW    36    3    0    YBowP*sc    Z8*sc    0    YBowP*sc    0    Rfeed
GW    37    3    0    YBowN*sc    Z8*sc    0    YBowN*sc    0    Rfeed
GW    38    3    0    YBowP*sc    -Z8*sc    0    YBowP*sc    0    Rfeed
GW    39    3    0    YBowN*sc    -Z8*sc    0    YBowN*sc    0    Rfeed
GW    40    11    0    -Lw*sc    Lh*sc    0    Lw*sc    Lh*sc    Rloop
GW    41    11    0    -Lw*sc    -Lh*sc    0    Lw*sc    -Lh*sc    Rloop
GW    42    23    0    -Lw*sc    Lh*sc    0    -Lw*sc    -Lh*sc    Rloop
GW    43    23    0    Lw*sc    Lh*sc    0    Lw*sc    -Lh*sc    Rloop
GS    0    0    0.0254
GE    0
LD    5    0    0    0    Cond    'Conductivity
GN    -1
EK
EX    0    1    1    0    1    0    0    'GW1 is SOURCE wire
FR    0    38    0    0    174    12
RP    0    1    73    1510    90    0    1    5    0    0
EN
This design is easier to build, has almost the same gain in Hi-VHF and UHF and has better SWR in both bands. Is anyone getting the same results with the original model?

I've added a 3d model of my idea for a PVC frame for my design. Antenna element and loop are white and PVC frame is yellow.


Model below adds 5 reflectors and greatly increases Hi-VHF gain. Hi-VHF becomes very directional, but UHF is still pretty good from the front and back.

Code:
CM Based on Kosmic SuperQuad 4-Bay, NO Reflector, 4nec2 by holl_ands, 1Mar2010
CM Reshaped to work better with US Repack.
CM Bowties increased to 1/4" Copper tubing.
CM Good UHF numbers with very usable HiVHF.
CM HiVHF can be improved with a 1/2" copper pipe loop, and reflectors can be added.
CM Simple SOURCE Wire. Modeled without Autoseg.
CM Source wire sized to 0.029 will be close enough to model HiVHF and UHF together.
CE
SY Scale=1.0
SY sc=Scale
SY Rsrc=0.029    'SOURCE wire Radius. Adjust for AGT=1.0:           UHF(540)=0.038  &   HiVHF(198)=0.020          No AutoSeg
SY Rbow=0.125    'Radius (in inches) of BOWTIE elements    1/4" tubing
SY Rfeed=0.0642    'FEEDLINE wire Radius   #8 wire
SY Rloop=0.3125    '0.3125       1/2" copper tubing (5/8"od)
SY Rrefl=0.125    '0.125         1/4" rods    SWR slightly better with 1/2" tubing
SY ZBowII=12.0    'Distance between the Centers of the two INNER bowties    12.0
SY ZBowOI=ZBowII    'From Center of INNER bowtie to Center of OUTER bowtie
SY BowLen=11.0    'Bow Half-Length - Assume all SAME (Reality +/- 0.25+ in)     11.0
SY BowSep=5.0    'Bow Tine Separation - Assume all SAME (Reality +/- 0.25 in)
SY FedSep=0.75    'Separation (in inches) between two FEEDLINE wires    0.75
SY Hop=FedSep    'Separation between Feedlines at Crossover                       Same as FedSep to work with PVC center support.
SY ZCross=6.0    'From Center of Feedline Crossover to Center of OUTER bowtie    5.58
SY ZClen=4.0    'From Center of Feedline Crossover to Inflection point    4.6
SY Cond=3.0e7    'Conductivity (Copper=3.0e7, Alum=2.0e7, StainlessSteel=1.67e7)
SY LoophighDelta=6.0    '5.0 better HiVHF     7.25 better for UHF
SY LoopwideDelta=0.5625    '.4375  1/8" gap              0.5625 for 1/4" gap      0.44215 to normalize length
SY Reflector0=36    'Length of center reflectors       49.5              48" is very close and cheaper.      36 is OK
SY Reflector1=Reflector0    'Length of first reflectors
SY Reflector2=Reflector0    'Length of second reflectors
SY Reflector3=Reflector0    'Length of third reflectors
SY Reflector4=Reflector0    'Length of fourth reflectors
SY Rdback=16.0    '15.8125        16.0
SY ZBowInr=ZBowII/2    'Distance from antenna center to center of INNER bowtie
SY ZBowOut=ZBowII/2+ZBowOI    'Distance from antenna center to center of OUTER bowtie
SY Z1=ZBowOut+BowSep/2
SY Z2=ZBowOut
SY Z3=ZBowOut-BowSep/2
SY Z4=ZBowOut-ZCross+ZClen    'Very long crossover region
SY Z5=ZBowOut-ZCross
SY Z6=ZBowOut-ZCross-ZClen    'Very long crossover region
SY Z7=ZBowInr+BowSep/2
SY Z8=ZBowInr
SY Z9=ZBowInr-BowSep/2
SY Z10=(Z2+Z8)/2
SY Z11=Z8*4
SY YBowN=-FedSep/2
SY YBowP=FedSep/2
SY YBow=(BowLen^2-(BowSep/2)^2)^0.5
SY Ymax=YBow+FedSep/2
SY Loophigh=Z1+LoophighDelta
SY Lh=Loophigh
SY Loopwide=Ymax+Loopwidedelta
SY Lw=Loopwide
SY R0Ypos=Reflector0/2
SY R1Ypos=Reflector1/2
SY R2Ypos=Reflector2/2
SY R3Ypos=Reflector3/2
SY R4Ypos=Reflector4/2
GW    1    1    0    YBowN*sc    0    0    YBowP*sc    0    Rsrc
GW    4    7    0    Ymax*sc    Z7*sc    0    YBowP*sc    Z8*sc    Rbow
GW    5    7    0    Ymax*sc    Z9*sc    0    YBowP*sc    Z8*sc    Rbow
GW    6    7    0    YBowN*sc    Z8*sc    0    -Ymax*sc    Z7*sc    Rbow
GW    7    7    0    YBowN*sc    Z8*sc    0    -Ymax*sc    Z9*sc    Rbow
GW    8    7    0    Ymax*sc    -Z7*sc    0    YBowP*sc    -Z8*sc    Rbow
GW    9    7    0    Ymax*sc    -Z9*sc    0    YBowP*sc    -Z8*sc    Rbow
GW    10    7    0    YBowN*sc    -Z8*sc    0    -Ymax*sc    -Z7*sc    Rbow
GW    11    7    0    YBowN*sc    -Z8*sc    0    -Ymax*sc    -Z9*sc    Rbow
GW    12    7    0    Ymax*sc    Z1*sc    0    YBowP*sc    Z2*sc    Rbow
GW    13    7    0    Ymax*sc    Z3*sc    0    YBowP*sc    Z2*sc    Rbow
GW    14    7    0    YBowN*sc    Z2*sc    0    -Ymax*sc    Z1*sc    Rbow
GW    15    7    0    YBowN*sc    Z2*sc    0    -Ymax*sc    Z3*sc    Rbow
GW    16    7    0    Ymax*sc    -Z1*sc    0    YBowP*sc    -Z2*sc    Rbow
GW    17    7    0    Ymax*sc    -Z3*sc    0    YBowP*sc    -Z2*sc    Rbow
GW    18    7    0    YBowN*sc    -Z2*sc    0    -Ymax*sc    -Z1*sc    Rbow
GW    19    5    0    YBowN*sc    -Z2*sc    0    -Ymax*sc    -Z3*sc    Rbow
GW    20    1    0    YBowP*sc    Z2*sc    0    YBowP*sc    Z4*sc    Rfeed
GW    21    1    0    YBowN*sc    Z2*sc    0    YBowN*sc    Z4*sc    Rfeed
GW    22    1    0    YBowP*sc    Z6*sc    0    YBowP*sc    Z8*sc    Rfeed
GW    23    1    0    YBowN*sc    Z6*sc    0    YBowN*sc    Z8*sc    Rfeed
GW    24    3    0    YBowN*sc    Z6*sc    (Hop/2)*sc    0    Z5*sc    Rfeed
GW    25    3    0    YBowP*sc    Z4*sc    (Hop/2)*sc    0    Z5*sc    Rfeed
GW    26    3    0    YBowP*sc    Z6*sc    (-Hop/2)*sc    0    Z5*sc    Rfeed
GW    27    3    0    YBowN*sc    Z4*sc    (-Hop/2)*sc    0    Z5*sc    Rfeed
GW    28    1    0    YBowP*sc    -Z2*sc    0    YBowP*sc    -Z4*sc    Rfeed
GW    29    1    0    YBowN*sc    -Z2*sc    0    YBowN*sc    -Z4*sc    Rfeed
GW    30    1    0    YBowP*sc    -Z6*sc    0    YBowP*sc    -Z8*sc    Rfeed
GW    31    1    0    YBowN*sc    -Z6*sc    0    YBowN*sc    -Z8*sc    Rfeed
GW    32    3    0    YBowN*sc    -Z6*sc    (-Hop/2)*sc    0    -Z5*sc    Rfeed
GW    33    3    0    YBowP*sc    -Z4*sc    (-Hop/2)*sc    0    -Z5*sc    Rfeed
GW    34    3    0    YBowP*sc    -Z6*sc    (Hop/2)*sc    0    -Z5*sc    Rfeed
GW    35    3    0    YBowN*sc    -Z4*sc    (Hop/2)*sc    0    -Z5*sc    Rfeed
GW    36    3    0    YBowP*sc    Z8*sc    0    YBowP*sc    0    Rfeed
GW    37    3    0    YBowN*sc    Z8*sc    0    YBowN*sc    0    Rfeed
GW    38    3    0    YBowP*sc    -Z8*sc    0    YBowP*sc    0    Rfeed
GW    39    3    0    YBowN*sc    -Z8*sc    0    YBowN*sc    0    Rfeed
GW    40    11    0    -Lw*sc    Lh*sc    0    Lw*sc    Lh*sc    Rloop
GW    41    11    0    -Lw*sc    -Lh*sc    0    Lw*sc    -Lh*sc    Rloop
GW    42    23    0    -Lw*sc    Lh*sc    0    -Lw*sc    -Lh*sc    Rloop
GW    43    23    0    Lw*sc    Lh*sc    0    Lw*sc    -Lh*sc    Rloop
GW    51    25    -Rdback*sc    -R1Ypos*sc    0    -Rdback*sc    R1Ypos*sc    0    Rrefl
GW    54    25    -Rdback*sc    -R2Ypos*sc    Z10*sc    -Rdback*sc    R2Ypos*sc    Z10*sc    Rrefl
GW    55    25    -Rdback*sc    -R2Ypos*sc    -Z10*sc    -Rdback*sc    R2Ypos*sc    -Z10*sc    Rrefl
GW    58    25    -Rdback*sc    -R4Ypos*sc    Z11*sc    -Rdback*sc    R4Ypos*sc    Z11*sc    Rrefl
GW    59    25    -Rdback*sc    -R4Ypos*sc    -Z11*sc    -Rdback*sc    R4Ypos*sc    -Z11*sc    Rrefl
GS    0    0    0.0254
GE    0
LD    5    0    0    0    Cond    'Conductivity
GN    -1
EK
EX    0    1    1    0    1    0    0    'GW1 is SOURCE wire
FR    0    38    0    0    174    12
RP    0    1    73    1510    90    0    1    5    0    0
EN
 

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Discussion Starter #4
My main backbone is also PVC. It is outdoor trim so it has the UV stabilizers in it just like PVC electrical conduit. Besides specialty stores I buy mine at menards. I haven't found it at lowes and not sure about homedepot but I haven't had any problems with wind loading and we get some strong winds sometimes. Its already weathered 40+ mph winds so far since its been up. I don't remember the exact price but I want to say it was in the 8 to 10 dollar range for an 8' section. The loops are 1/2" type m copper. My upper and lower loops are electrically separated but I wonder if they could be tied together without hurting their function or even made into one big loop as you have modeled. If they can be it would make assembly much easier. My whiskers are made from 8 gauge solid copper ground wire and my transmission lines are from 4 ought wire stripped so its10 gauge wire measured with a pair of wire strippers. I used the drill method to straighten them. The whiskers are soldered to the transmission line with silver solder. I still wished I had a bowtie to put up in same location to do real world testing but maybe one day ill have the time to build one. I was using a commercial hdb8x before this one and it was not stable. Some channels was stable and others came and went. I did a few mods on it that helped a bit but wasn't happy with it. This coming summer I hope to have the time to get my tower up and maybe after that maybe Ill have time to build a few more antennas to play with.
 

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ljavener, I downloaded and looked at the same model. I see the same "warnings" that you did in 4nec2. I see the same type of warning in nikiml's scripts, but do get results upon eval.
Generally speaking when it comes to code and software, I think of warnings as just that. a Warning. But shouldn't prevent some thing from working. "errors" on the other hand will.
Also noted that model was created 6 years ago ~2015, so holl_ands may have used an older version of 4nec2, and certainly nikiml python scripts have changed some since then too.

I assume that holl_ands used nikiml's python scripts to optimize that model, as indicated by the 'OPT' and 'EVAL' comments in there. There is also an option for both 'nec_opt' and 'nec_eval' to disable geometry checks. I assume nikiml included those options for this very reason. ie if some warning is deemed not a big deal by the user, allow the user to ignore 'em by not running the geometry check.
Syntax to disable geometry check:
--validate-geometry=0

Have you tried to rerun the optimization of the existing model with nikiml's python scripts after making your modification? I presume your change was changing 'Z8' to 'Z7' in the 4 wires flagged? My guess is that after doing so, it might come up with some other similar warning after the re-OPT completes and it comes up with a new solution.
 

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I modified some of the OPT parms in the original file, but left the symbols of wires 2,4,6,8, 11,13,15,17 alone, and let it optimize for a while to find new solutions. I stopped it after about a half hour to an hour, opened the output file with 4nec2 (under wine), and ran the 4nec2 geometry check, and it passed with no errors or warnings. So far it's uhf net gain is 10-12 dBi, with vswr mostly below 2:1, taking a turn for the worse at the upper end of the repack band. I am gonna let this optimization run for a while with nikiml's python scripts and see where it lands... (it's optimizing 8 Symbols as in the original file).
 

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i think the issue with the original model is in the amount of freedom given to the variables that make up the UHF elements. In watching the model optimize, I think if ya just limit the freedom in say tine separation, and length it will find
solutions such that the bow ties don't overlap, causing that warning. Gonna do that here and see what happens.

Code:
' INNER & OUTER Bow Whisker Length (lose some in bend):
SY BowLeni=9.807659' 7, 20
SY BowLeno=BowLeni' [IDENTCAL...NOT FREE FORM]
' Distance between the centers of the two INNER bowties:
SY ZBowII=16.16931' 7, 20
' From center of INNER bowtie to center of OUTER bowtie:
SY ZBowOI=8.790186' 7, 20
' INNER & OUTER Bow Forward Sweep distance at tip of the whisker:
SY BowSwpi=0
SY BowSwpo=BowSwpi' [IDENTCAL...NOT FREE FORM]
' INNER & OUTER Bow Tine Separation:
SY TineSepi=8.788456' 2, 15
SY TineSepo=TineSepi' [IDENTCAL...NOT FREE FORM]
' Separation between two FEEDLINE wires:
SY FeedSep=1.44474' 0.75, 6
' From center of Feedline Cross-Over to center of OUTER Bowtie:
SY ZCross=1.26022' 1.25, 6
 

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Majortom
Generally speaking when it comes to code and software, I think of warnings as just that. a Warning. But shouldn't prevent some thing from working. "errors" on the other hand will.
Normally I agree with you concerning warnings and errors, but in this case it seems to make a major difference in the results. My guess is that 4nec2 assumes that wires that are overlapping do not have an electrical connection. If wires end at the same coordinates, 4nec2 assumes that they do have an electrical connection. If you build an antenna with the wires connected, or a bend in the wire, the results will be different than the model that has overlapping wires. To test this theory I modeled a GH Element and then reran it with one of the elbows overlapping(see below). The results for SWR, gain and impedance are very different when the wires overlap.

Code:
CM GH element only
CE
SY radius=0.003175
SY narod_surf_spacing=0.006
SY narod_spacing=0.012
SY feed=0.03776106    '0.02, 0.07
SY b=0.121252    '0.075, 0.25
SY a1=0.1945679    '0.07, 0.22
SY _G3=0.06374546    '0.006, 0.1
SY a2=a1+feed-_G3    'this is to avoid self intersection since _G3 is to be > radius+2.5mm
SY a3=0.1321573    '0.07, 0.22
SY x=-0.07477662    '-0.1, -0.06
SY g1=0.04301694    '0.002, 0.045
SY g2=0.04430498    '0.002, 0.045
SY g3=0.006236525    '0.002, 0.045
SY l1=0.3144561    '0.1, 0.6
SY l2=0.4490271    '0.1, 0.65
SY l3=0.5567192    '0.1, 0.65
SY n_h=0.08642624    '0.05, 0.14
SY n_f_dx=0
SY n_top_dy=-0.03529455    '-0.06, 0.04
SY n_b_taper=0.0445677    '0, 0.1
SY n_top=_G3+a3+n_top_dy- n_b_taper/2    'hat head size
SY n_f=x + n_f_dx    'so the hat does not tilt behind the reflectors
SY narod_top = a1+a2+a3+narod_spacing+n_h    'want to put 3 reflectors between z=very_small and z=narod_top +/- very_small,  1 reflectors around narod_top and 1 above it
SY dz3=0.1409803    '0.017, 0.15
SY above_below=-1
SY sign = abs(above_below)/above_below    'may fail at 0
SY z3 = sign*dz3+narod_top
SY dz = z3/5
SY dz1=1.72834    '0.2, 2
SY z1 = (1+(dz1-1))*dz
SY dz2=1.733665    '0.2, 2
SY z2 = (3+(dz2-1))*dz
SY ay1=feed+a1
SY ay2=feed+a1-a2
SY ay3=feed+a1-a2+a3
SY ay4=feed+a1-a2+a3+b
SY az2=a1+a2
SY az3=a1+a2+a3
SY n_b_z=az3+narod_spacing
SY n_b_y1=n_top+n_b_taper
SY n_b_y2=n_b_y1+b
SY n_z_coef=0.7314852    '0.5, 1.4
SY n_zsz=0.4049281    '0.3, 0.55
SY n_0sz=0.4701482    '0.3, 0.6
SY n_x_diff=0.2752484    '0.15, 0.4
SY n_x = x-n_x_diff
SY n_z = narod_top*n_z_coef
GW    1    15    0    feed    0    0    ay1    a1    radius    '#00f
GW    2    13    0    ay1    a1    0    ay2    az2    radius    '#00f
GW    3    9    0    ay2    az2    0    ay3    az3    radius    '#00f
GW    4    7    0    ay3    az3    0    ay4    az3    radius    '#00f
GX    20    010
GX    40    001
GW    100    5    0    -feed    0    0    feed    0    radius*.8675    '#f40
GE    0
LD    5    0    0    0    24900000
GN    -1
EK
EX    0    100    3    0    1    0    0
FR    0    48    0    0    470    3
RP    0    1    73    1510    90    0    1    5    0    0
EN

Code:
CM GH element only created to test errors with overlapping wires
CE
SY radius=0.003175
SY narod_surf_spacing=0.006
SY narod_spacing=0.012
SY feed=0.03776106    '0.02, 0.07
SY b=0.121252    '0.075, 0.25
SY a1=0.1945679    '0.07, 0.22
SY _G3=0.06374546    '0.006, 0.1
SY a2=a1+feed-_G3    'this is to avoid self intersection since _G3 is to be > radius+2.5mm
SY a3=0.1321573    '0.07, 0.22
SY x=-0.07477662    '-0.1, -0.06
SY g1=0.04301694    '0.002, 0.045
SY g2=0.04430498    '0.002, 0.045
SY g3=0.006236525    '0.002, 0.045
SY l1=0.3144561    '0.1, 0.6
SY l2=0.4490271    '0.1, 0.65
SY l3=0.5567192    '0.1, 0.65
SY n_h=0.08642624    '0.05, 0.14
SY n_f_dx=0
SY n_top_dy=-0.03529455    '-0.06, 0.04
SY n_b_taper=0.0445677    '0, 0.1
SY n_top=_G3+a3+n_top_dy- n_b_taper/2    'hat head size
SY n_f=x + n_f_dx    'so the hat does not tilt behind the reflectors
SY narod_top = a1+a2+a3+narod_spacing+n_h    'want to put 3 reflectors between z=very_small and z=narod_top +/- very_small,  1 reflectors around narod_top and 1 above it
SY dz3=0.1409803    '0.017, 0.15
SY above_below=-1
SY sign = abs(above_below)/above_below    'may fail at 0
SY z3 = sign*dz3+narod_top
SY dz = z3/5
SY dz1=1.72834    '0.2, 2
SY z1 = (1+(dz1-1))*dz
SY dz2=1.733665    '0.2, 2
SY z2 = (3+(dz2-1))*dz
SY ay1=feed+a1
SY ay2=feed+a1-a2
SY ay3=feed+a1-a2+a3
SY ay4=feed+a1-a2+a3+b
SY az2=a1+a2
SY az3=a1+a2+a3
SY n_b_z=az3+narod_spacing
SY n_b_y1=n_top+n_b_taper
SY n_b_y2=n_b_y1+b
SY n_z_coef=0.7314852    '0.5, 1.4
SY n_zsz=0.4049281    '0.3, 0.55
SY n_0sz=0.4701482    '0.3, 0.6
SY n_x_diff=0.2752484    '0.15, 0.4
SY n_x = x-n_x_diff
SY n_z = narod_top*n_z_coef
GW    1    15    0    feed    0    0    ay1    a1+0.01    radius    '#00f
GW    2    13    0    ay1-0.01    a1    0    ay2    az2    radius    '#00f
GW    3    9    0    ay2    az2    0    ay3    az3    radius    '#00f
GW    4    7    0    ay3    az3    0    ay4    az3    radius    '#00f
GX    20    010
GX    40    001
GW    100    5    0    -feed    0    0    feed    0    radius*.8675    '#f40
GE    0
LD    5    0    0    0    24900000
GN    -1
EK
EX    0    100    3    0    1    0    0
FR    0    48    0    0    470    3
RP    0    1    73    1510    90    0    1    5    0    0
EN
I also tested a model that had the two wires very close, but not connected or overlapping, at the elbow. The results of this model are very close to the one that has overlapping wires, but very different from the one that has connected wires. I think this is one warning that should have been labeled as an error.
 

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Agree with ya...
Kinda my point, the original model says it's a 4Bay, and a 4bay bow tie doesn't have the bow ends touching.
It's just that the symbols used in creating the structure allowed the wires between Bows to overlap at the end in that instance.
A bow tie doesn't have the ends attached. So limit the symbols. By adjusting the symbols one can work around it to find other solutions. But if ur throwing the kitchen sink at the optimizer to find optimum values it shouldn't get disaapointed by such warnings in one iteration. It will continue on with crunching other solutions.
 

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mr_circuit

We got a bit off track from your original post. If you weren't able to follow our discussion, I think that the antenna you built, will actually work better if you clip the center elbow of each "W" shaped element and create two "V" shaped elements out of each. The tips just need to be separated by an 1/8th" or so. It won't make a huge difference, but may help enough to make a few channels more stable. Even if you make this change to the design, Holl_ands design was created before the repack, and there are newer designs that work even better. Choosing the best one will require more information about the channels that you are interested in, and your more precise location. List your TVFool report and which channels you are interested in, and we can suggest some designs. What little I could see, from your city center, it looks like the only Hi-VHF channels are in Indianapolis, but you have UHF signals mainly from two areas that are approximately 180 degrees apart. The Muncie signals are pretty close to being 90 degrees to the side. Depending on your exact location, these are only estimates. Most 4 bay bowtie designs, without reflectors work very well from the front and the back, but have very little reception directly to the side. Adding the loop definitely helps with Hi-VHF reception from the front and back. I've got a design for a 4bay bowtie antenna, with loop and reflectors, that has very good Hi-VHF reception from the front, but gets very good UHF reception from both the front and back. Give us a bit more information, and we can see if this one would work better for you. Let us know if you get a chance to clip the W elements, on your existing design, and how much, if any it helped.
 

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Discussion Starter #11 (Edited)
ljhavener Its ok if you all go off track a bit, I consider all this a good way of learning and the more information the better. I also appreciate you and majortom running the computer models. If I had more free time I would learn the software also but I just don't have that kind of time right now so I do appreciate you both for running holl-ands original model. Right now we are kinda in the middle of winter and there is about 7" of snow still on the ground so I won't be messing with my antenna right now but come summer I am hopping to be able to play with it some more. Maybe then I will try clipping the element to make separate whiskers. Or if you don't mind sharing your design that has the bowties with a loop with all the dimensions I might even try to build it so I can test both to see how a bowtie would compare. Here is a link to rabbit ears report for a more precise location. RabbitEars.Info We don't have any tall buildings or anything really to get in the way of the signal from Indy side. The only thing that could possibly cause an issue is a large water tower but I have already verified its not in the line of my signal path. We used to have high voltage power lines in my front yard that fed power to half my town but they moved them much further south of me about a year ago. I hope I don't come across as a smart A-hole when I say this next part because I am always learning more everyday and appreciate forums like these because they provide so much valuable information shared by everyone on here. I have a good understanding on the science behind antennas and how they work because of my history. I was big into CB radios as a teenager and also took a class all about antennas and wave guides and dishes as part of earning my electrical engineering degree but that was like 20 years ago. I am receiving probably like 99 percent of the channels I would like to get solidly. There is just a couple that would be nice to have that I would like to try and get. The two from marion the other half really wants but I know I gotta get over the trees in my backyard to have any chance of getting them good.
 
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