From nikml - Canadian TV, Computing and Home Theatre Forums

 
LinkBack Thread Tools Search this Thread Display Modes

post #1 of 12 (permalink) Old 2017-12-24, 01:58 PM Thread Starter
Rookie
 
Join Date: Nov 2017
Posts: 17
So I went ahead and built the BQ8U from NIKML- just curious as to how far back to mount the reflector? I am using a 1 x 2 mesh- but have access to the actual elements in the graphic design - thank you for your help huge fan of many of you guys!
Otaobsession is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 2017-12-27, 01:20 AM
Veteran
 
Join Date: Nov 2008
Location: San Diego, CA
Posts: 3,084
As always, nikiml included an Interactive Diagram showing Dimensions as you roll cursor over the line mid-points (Length) and line end-points (X, Y, Z Coordinates). Click on "in" or "mm" in bottom-left to select unit type.
nikiml's Antenna pages - Bi-Quad with 8 reflector rods optimized for UHF
Note that in Diagram, nikiml's Optimized BQ8U Active Bi-Quad, X-Coord not all 0.0, say WHAT????? Must be a MISTAKE....in his posted 4nec2 file, X-Coord for Active Bi-Quad elements are ALL set to 0.0.

Antenna Simulations, Overload Calculations, etc: http://imageevent.com/holl_ands

Last edited by holl_ands; 2017-12-27 at 01:39 AM.
holl_ands is offline  
post #3 of 12 (permalink) Old 2017-12-27, 07:48 AM Thread Starter
Rookie
 
Join Date: Nov 2017
Posts: 17
Hence the question my engineer friend I do want to say this this damn thing is the work horse
Otaobsession is offline  
 
post #4 of 12 (permalink) Old 2017-12-28, 09:13 AM
Veteran
 
Join Date: Jan 2009
Posts: 4,296
I am not sure what you guys are seeing, but it appears to me in the interactive diagram, that the reflector should be 3 1/4" behind the active elements. I have not looked at the Nec model.

DB4E/VHF Yagi rotor FM Bandstop ap-8700 preamp 4way split LG lcd.
majortom is online now  
post #5 of 12 (permalink) Old 2017-12-30, 08:52 AM Thread Starter
Rookie
 
Join Date: Nov 2017
Posts: 17
Quote:
Originally Posted by majortom View Post
I am not sure what you guys are seeing, but it appears to me in the interactive diagram, that the reflector should be 3 1/4" behind the active elements. I have not looked at the Nec model.
thank you sir- i have the DE AT 5” in front of the 1” X2” reflector. I get ALL UHF in southern direction, including most VHF HI? Should I attempt to bring the grid in 1-3/4”, or leave it alone? Also, could i stack two of these 180° from one another horizontally? I would leave approx 7’ in between units. Any suggestions on DIY combining? I wd post my TVF report but being a “rook” i am not entitled to. Thanks again!
Otaobsession is offline  
post #6 of 12 (permalink) Old 2017-12-30, 08:54 AM Thread Starter
Rookie
 
Join Date: Nov 2017
Posts: 17
Holl_ANDS- your thoughts sir?
Otaobsession is offline  
post #7 of 12 (permalink) Old 2017-12-31, 10:19 AM
Rookie
 
Join Date: Apr 2017
Posts: 26
How about showing us a picture of what you built?
lenlab is offline  
post #8 of 12 (permalink) Old 2017-12-31, 07:13 PM
Yurii Pylypenko is online now  
post #9 of 12 (permalink) Old 2018-01-03, 01:08 PM
Veteran
 
Join Date: Nov 2008
Location: San Diego, CA
Posts: 3,084
You can simply use 2-port RF Combiner (with about 3+ dB Loss).

I'm vacillating whether I/we want to volunteer to Optimize Low-Loss HHH [Holl_ands Horizontal Harness], modifying nikiml's 4nec2 files....I would prefer to take the time to bring someone ELSE up to speed running nikiml's Python Optimization Scripts....or at LEAST prepare the Horizontally Stacked File [copy/paste from one of my H-Stk files] so that my Grandson can run it.

nikiml's EVAL Summary with RR's moved to 5-in, shows expected small improvement in SWR [also F/B & F/R Ratio] at the expense of somewhat lower Raw Gain:

Code:
Input file : Z:\4nec2_PLUS\U\U - BiQuad\
U - BiQuad+8RR - nikiml BQ8U\UHF_BiQuad+8RR_nikiml_BQ8U_ x=5-in.nec
Freq sweeps: [(174, 3, 15), (470, 12, 29)]
Autosegmentation: NO

         --- Gain ---              -- Ratios -- -- Impedance --
   Freq    Raw    Net   SWR BeamW    F/R    F/B    Real     Imag   AGT   corr
============================================================================
  174.0   5.11  -6.49 55.84  73.8   6.69   6.69    35.62    711.09 1.01  0.06
  177.0   5.33  -6.42 57.75  73.8   7.21   7.21    39.85    773.96 1.01  0.06
  180.0   5.52  -6.28 58.50  73.8   7.61   7.61    46.05    846.36 1.01  0.06
  183.0   5.71  -6.09 58.39  73.6   7.92   7.92    54.80    931.22 1.01  0.05
  186.0   5.86  -5.88 57.66  73.7   8.13   8.13    67.07   1032.56 1.01  0.05
  189.0   6.01  -5.65 56.52  73.5   8.27   8.27    84.53   1156.10 1.01  0.05
  192.0   6.14  -5.41 55.14  73.5   8.32   8.32   109.95   1310.40 1.01  0.05
  195.0   6.26  -5.17 53.67  73.4   8.28   8.28   148.29   1508.79 1.01  0.05
  198.0   6.36  -4.96 52.28  73.4   8.13   8.13   208.97   1773.40 1.01  0.05
  201.0   6.46  -4.77 51.16  73.3   7.88   7.88   311.46   2143.58 1.01  0.05
  204.0   6.54  -4.65 50.60  73.2   7.48   7.48   501.34   2696.59 1.01  0.05
  207.0   6.64  -4.59 51.13  72.9   6.89   6.89   907.24   3606.62 1.01  0.03
  210.0   6.68  -4.78 53.92  72.9   5.98   5.98  2030.94   5352.56 1.01  0.03
  213.0   6.69  -5.36 62.12  72.7   4.62   4.62  7652.07   9165.02 1.01  0.03
  216.0   6.59  -6.81 85.52  72.0   2.52   2.52 11934.90 -12794.50 1.01  0.03

  470.0  10.97  10.56  1.86  55.0  14.57  14.57  173.92   68.74 1.01  0.05
  482.0  11.18  10.80  1.81  52.1  13.00  13.00  180.77   73.22 1.01  0.05
  494.0  11.29  10.94  1.77  50.3  11.75  11.75  187.70   80.04 1.01  0.05
  506.0  11.26  10.93  1.74  50.3  10.72  10.72  197.02   88.92 1.01  0.05
  518.0  11.08  10.79  1.68  52.6   9.93   9.93  210.87   97.79 1.01  0.05
  530.0  10.79  10.55  1.60  58.1   9.43   9.43  229.30  103.15 1.01  0.05
  542.0  10.48  10.30  1.51  65.6   9.19   9.19  249.75  102.49 1.01  0.05
  554.0  10.24  10.11  1.42  72.3   9.15   9.15  269.03   95.74 1.01  0.05
  566.0  10.08   9.99  1.34  76.7   9.21   9.21  285.08   84.36 1.01  0.05
  578.0  10.00   9.94  1.26  79.3   9.32   9.32  297.04   70.04 1.01  0.04
  590.0   9.97   9.93  1.20  80.4   9.45   9.45  304.76   54.18 1.01  0.04
  602.0   9.97   9.95  1.14  80.3   9.57   9.57  308.38   37.92 1.01  0.04
  614.0  10.01  10.00  1.08  79.4   9.72   9.72  308.21   22.21 1.01  0.04
  626.0  10.08  10.08  1.03  77.3   9.88   9.88  304.75    7.86 1.01  0.04
  638.0  10.19  10.19  1.02  74.1  10.06  10.06  298.74   -4.46 1.01  0.04
  650.0  10.34  10.34  1.06  69.9  10.22  10.22  291.17  -14.40 1.01  0.04
  662.0  10.55  10.54  1.10  63.6  10.01  10.25  283.26  -22.27 1.01  0.04
  674.0  10.79  10.77  1.14  56.5   9.62   9.87  275.80  -29.45 1.01  0.03
  686.0  10.92  10.89  1.19  50.3   8.85   8.85  267.62  -38.07 1.01  0.03

  698.0  10.81  10.75  1.27  46.0   7.36   7.36  254.85  -47.83 1.01  0.03
  710.0  10.35  10.25  1.37  44.7   5.67   5.67  236.00  -53.62 1.01  0.03
  722.0   9.52   9.36  1.48  55.3   3.83   3.83  215.31  -52.22 1.01  0.03
  734.0   8.33   8.10  1.59  85.1   2.01   2.01  195.89  -44.72 1.01  0.03
  746.0   6.94   6.64  1.70  94.7   0.43   0.43  179.54  -32.10 1.01  0.03
  758.0   5.46   5.09  1.80 100.0  -1.01  -1.01  167.60  -16.36 1.01  0.03
  770.0   3.83   3.41  1.88 103.6  -2.49  -2.49  159.87    0.64 1.01  0.04
  782.0   1.98   1.51  1.94 106.7  -4.17  -4.17  155.75   17.91 1.01  0.04
  794.0  -0.23  -0.72  1.97 109.6  -6.19  -6.19  154.72   34.88 1.01  0.04
  806.0  -2.99  -3.50  1.99 112.2  -8.76  -8.76  156.38   51.18 1.01  0.04
Compare to nikiml's Original BQ8U:

Code:
Input file : Z:\4nec2_PLUS\U\U - BiQuad\
U - BiQuad+8RR - nikiml BQ8U\UHF_BiQuad+8RR_nikiml_BQ8U.nec
Freq sweeps: [(174, 3, 15), (470, 12, 29)]
Autosegmentation: NO

         --- Gain ---              -- Ratios -- -- Impedance --
   Freq    Raw    Net   SWR BeamW    F/R    F/B    Real    Imag  AGT  corr
==========================================================================
  174.0   4.06  -5.99  38.48 74.3   3.64   3.64   46.11   663.72 1.01  0.06
  177.0   4.27  -6.18  42.42 74.3   4.09   4.09   49.09   729.87 1.01  0.06
  180.0   4.47  -6.29  45.62 74.2   4.48   4.48   54.14   805.19 1.01  0.06
  183.0   4.67  -6.31  48.17 74.2   4.84   4.84   61.65   893.03 1.01  0.05
  186.0   4.86  -6.29  50.22 74.1   5.16   5.16   72.40   997.94 1.01  0.05
  189.0   5.04  -6.25  51.90 74.0   5.44   5.44   87.75  1126.47 1.01  0.05
  192.0   5.21  -6.20  53.36 74.0   5.68   5.68  110.06  1288.59 1.01  0.05
  195.0   5.40  -6.12  54.82 73.9   5.87   5.87  143.58  1500.52 1.01  0.03
  198.0   5.57  -6.08  56.53 73.7   6.01   6.01  196.59  1790.65 1.01  0.03
  201.0   5.74  -6.09  58.91 73.6   6.09   6.09  287.00  2213.87 1.01  0.03
  204.0   5.91  -6.18  62.70 73.5   6.06   6.06  460.77  2892.55 1.01  0.03
  207.0   6.15  -6.37  69.48 73.3   5.88   5.88  874.21  4168.03 0.99 -0.03
  210.0   6.35  -6.94  83.31 73.1   5.42   5.42 2478.00  7464.20 0.99 -0.03
  213.0   6.56  -8.18 117.15 72.7   4.37   4.37 33458.50 7512.62 0.99 -0.03
  216.0   6.54 -10.78 213.66 71.3   2.12   2.12 1069.54 -8204.96 0.99 -0.03

  470.0  11.02  10.19  2.43  51.3  11.27  11.27  152.71  129.93 1.01  0.05
  482.0  11.33  10.62  2.27  47.4  10.19  10.19  168.21  136.56 1.01  0.05
  494.0  11.57  10.93  2.18  44.5   9.36   9.36  181.58  143.69 1.01  0.05
  506.0  11.73  11.13  2.12  42.8   8.69   8.69  194.53  153.61 1.01  0.05
  518.0  11.78  11.20  2.09  42.4   8.19   8.19  210.83  167.20 1.01  0.05
  530.0  11.71  11.17  2.04  43.5   7.89   7.89  234.66  182.13 1.01  0.05
  542.0  11.58  11.09  1.97  45.9   7.77   7.77  267.99  193.46 1.01  0.05
  554.0  11.44  11.02  1.88  49.1   7.77   7.77  309.72  195.63 1.01  0.05
  566.0  11.33  10.97  1.79  52.2   7.85   7.85  356.04  183.95 1.01  0.05
  578.0  11.25  10.96  1.70  55.0   7.95   7.95  400.78  155.47 1.01  0.05
  590.0  11.22  10.97  1.62  57.1   8.06   8.06  436.04  110.45 1.01  0.04
  602.0  11.21  11.00  1.55  58.4   8.17   8.17  454.15   53.70 1.01  0.04
  614.0  11.21  11.03  1.50  59.0   8.25   8.25  450.87   -5.92 1.01  0.04
  626.0  11.24  11.08  1.48  58.7   8.34   8.34  427.70  -58.53 1.01  0.04
  638.0  11.30  11.14  1.47  57.3   8.42   8.42  390.94  -97.21 1.01  0.04
  650.0  11.38  11.21  1.49  54.9   8.46   8.46  348.54 -119.84 1.01  0.04
  662.0  11.50  11.31  1.52  51.2   8.40   8.40  307.03 -128.30 1.01  0.04
  674.0  11.67  11.45  1.57  46.2   8.12   8.12  270.21 -126.38 1.01  0.03
  686.0  11.80  11.54  1.63  40.9   7.49   7.49  239.20 -117.95 1.01  0.03
  698.0  11.84  11.53  1.70  35.8   6.57   6.57  213.65 -105.51 1.01  0.03

  710.0  11.67  11.32  1.77  31.8   5.39   5.39  193.58  -90.95 1.01  0.04
  722.0  11.25  10.84  1.86  29.9   4.01   4.01  177.37  -77.50 1.01  0.04
  734.0  10.48   9.98  1.99  33.5   2.70   2.70  160.01  -63.79 1.01  0.04
  746.0   9.46   8.84  2.15  59.8   1.68   1.68  143.67  -44.77 1.01  0.04
  758.0   8.35   7.63  2.28  71.2   0.83   0.83  132.47  -22.30 1.01  0.04
  770.0   7.13   6.34  2.38  76.0  -0.05  -0.05  126.31    0.78 1.01  0.04
  782.0   5.76   4.93  2.43  79.7  -1.04  -1.04  124.11   23.39 1.01  0.05
  794.0   4.19   3.34  2.46  82.3  -2.22  -2.22  125.15   45.20 1.01  0.05
  806.0   2.34   1.49  2.46  84.5  -3.67  -3.67  129.02   66.12 1.01  0.05

Antenna Simulations, Overload Calculations, etc: http://imageevent.com/holl_ands

Last edited by holl_ands; 2018-01-03 at 01:48 PM.
holl_ands is offline  
post #10 of 12 (permalink) Old 2018-01-05, 10:42 AM Thread Starter
Rookie
 
Join Date: Nov 2017
Posts: 17
https://imgur.com/gallery/PmCMA

As you can see the grid is oversized and has been beaten badly by wind.... but even when this beast was ON THE GROUND , i still pulled 13 channels.
Otaobsession is offline  
post #11 of 12 (permalink) Old 2018-01-05, 10:46 AM Thread Starter
Rookie
 
Join Date: Nov 2017
Posts: 17
Thank you hollands!!
Otaobsession is offline  
post #12 of 12 (permalink) Old 2018-01-05, 10:53 AM Thread Starter
Rookie
 
Join Date: Nov 2017
Posts: 17
Quote:
Originally Posted by lenlab View Post
How about showing us a picture of what you built?
https://imgur.com/gallery/PmCMA
Otaobsession is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Canadian TV, Computing and Home Theatre Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome