F/B not to bad easy build - Canadian TV, Computing and Home Theatre Forums

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post #1 of 35 (permalink) Old 2018-03-20, 09:39 PM Thread Starter
 
Join Date: Jan 2009
Posts: 443
Wink F/B not to bad easy build

if you can get 1/4 copper tubing , 6- Ts , 4- 90 elbows
some 2x4 wire mesh
not to bad of antenna

Code:
CM Quadruple Quad,    wildwillie  march 20 2018
CM if you what to rescale (Frequance in feet /4 ) x12
CM A justing the wire mesh width of 2x4 will only reduce F/B and bring up gain a little
CM think out of the box if you want more gain "what if" lol
CM SWR seems not to bad
CE
GW	1	3	0	0.6	0	0	-0.9	0	0.05094856
GW	2	9	0	-2.88	5.4375	0	2.5575	5.4375	0.05094856
GW	3	9	0	-2.88	5.4375	0	-2.88	0	0.05094856
GW	4	9	0	-2.88	10.875	0	-2.88	5.4375	0.05094856
GW	5	9	0	-2.88	0	0	-2.88	-5.438	0.05094856
GW	6	9	0	-2.88	10.875	0	2.5575	10.875	0.05094856
GW	7	9	0	-2.88	-5.438	0	2.5575	-5.438	0.05094856
GW	8	9	0	-2.88	-5.438	0	-2.88	-10.88	0.05094856
GW	9	9	0	-2.88	-10.88	0	2.5575	-10.88	0.05094856
GW	10	9	0	2.5575	-5.438	0	2.5575	-10.88	0.05094856
GW	11	9	0	2.5575	3.e-15	0	2.5575	-5.438	0.05094856
GW	12	9	0	2.5575	5.4375	0	2.5575	3.e-15	0.05094856
GW	13	9	0	2.5575	10.875	0	2.5575	5.4375	0.05094856
GW	14	3	0	0.6	0	0	2.5575	3.e-15	0.05094856
GW	15	3	0	-0.9	0	0	-2.88	0	0.05094856
GW	17	7	-5.5	-8	10	-5.5	-4	10	0.05094856
GW	18	3	-5.5	-4	10	-5.5	-4	12	0.05094856
GW	19	7	-5.5	-4	12	-5.5	-8	12	0.05094856
GW	20	7	-5.5	-4	12	-5.5	0	12	0.05094856
GW	21	3	-5.5	0	12	-5.5	0	10	0.05094856
GW	22	7	-5.5	0	10	-5.5	-4	10	0.05094856
GW	23	7	-5.5	0	12	-5.5	4	12	0.05094856
GW	24	3	-5.5	4	12	-5.5	4	10	0.05094856
GW	25	7	-5.5	4	10	-5.5	0	10	0.05094856
GW	26	7	-5.5	4	10	-5.5	8	10	0.05094856
GW	28	7	-5.5	8	12	-5.5	4	12	0.05094856
GW	30	7	-5.5	-8	8	-5.5	-4	8	0.05094856
GW	31	3	-5.5	-4	8	-5.5	-4	10	0.05094856
GW	34	3	-5.5	0	10	-5.5	0	8	0.05094856
GW	35	7	-5.5	0	8	-5.5	-4	8	0.05094856
GW	37	3	-5.5	4	10	-5.5	4	8	0.05094856
GW	38	7	-5.5	4	8	-5.5	0	8	0.05094856
GW	39	7	-5.5	4	8	-5.5	8	8	0.05094856
GW	42	7	-5.5	-8	6	-5.5	-4	6	0.05094856
GW	43	3	-5.5	-4	6	-5.5	-4	8	0.05094856
GW	44	3	-5.5	0	8	-5.5	0	6	0.05094856
GW	45	7	-5.5	0	6	-5.5	-4	6	0.05094856
GW	46	3	-5.5	4	8	-5.5	4	6	0.05094856
GW	47	7	-5.5	4	6	-5.5	0	6	0.05094856
GW	48	7	-5.5	4	6	-5.5	8	6	0.05094856
GW	51	7	-5.5	-8	4	-5.5	-4	4	0.05094856
GW	52	3	-5.5	-4	4	-5.5	-4	6	0.05094856
GW	53	3	-5.5	0	6	-5.5	0	4	0.05094856
GW	54	7	-5.5	0	4	-5.5	-4	4	0.05094856
GW	55	3	-5.5	4	6	-5.5	4	4	0.05094856
GW	56	7	-5.5	4	4	-5.5	0	4	0.05094856
GW	57	7	-5.5	4	4	-5.5	8	4	0.05094856
GW	60	7	-5.5	-8	2	-5.5	-4	2	0.05094856
GW	61	3	-5.5	-4	2	-5.5	-4	4	0.05094856
GW	62	3	-5.5	0	4	-5.5	0	2	0.05094856
GW	63	7	-5.5	0	2	-5.5	-4	2	0.05094856
GW	64	3	-5.5	4	4	-5.5	4	2	0.05094856
GW	65	7	-5.5	4	2	-5.5	0	2	0.05094856
GW	66	7	-5.5	4	2	-5.5	8	2	0.05094856
GW	69	7	-5.5	-8	-5.464e-15	-5.5	-4	-5.464e-15	0.05094856
GW	70	3	-5.5	-4	-5.464e-15	-5.5	-4	2	0.05094856
GW	71	3	-5.5	0	2	-5.5	0	-5.464e-15	0.05094856
GW	72	7	-5.5	0	-5.464e-15	-5.5	-4	-5.464e-15	0.05094856
GW	73	3	-5.5	4	2	-5.5	4	-5.464e-15	0.05094856
GW	74	7	-5.5	4	-5.464e-15	-5.5	0	-5.464e-15	0.05094856
GW	75	7	-5.5	4	-5.464e-15	-5.5	8	-5.464e-15	0.05094856
GW	78	7	-5.5	-8	-2	-5.5	-4	-2	0.05094856
GW	79	3	-5.5	-4	-2	-5.5	-4	-5.464e-15	0.05094856
GW	80	3	-5.5	0	-5.464e-15	-5.5	0	-2	0.05094856
GW	81	7	-5.5	0	-2	-5.5	-4	-2	0.05094856
GW	82	3	-5.5	4	-5.464e-15	-5.5	4	-2	0.05094856
GW	83	7	-5.5	4	-2	-5.5	0	-2	0.05094856
GW	84	7	-5.5	4	-2	-5.5	8	-2	0.05094856
GW	87	7	-5.5	-8	-4	-5.5	-4	-4	0.05094856
GW	88	3	-5.5	-4	-4	-5.5	-4	-2	0.05094856
GW	89	3	-5.5	0	-2	-5.5	0	-4	0.05094856
GW	90	7	-5.5	0	-4	-5.5	-4	-4	0.05094856
GW	91	3	-5.5	4	-2	-5.5	4	-4	0.05094856
GW	92	7	-5.5	4	-4	-5.5	0	-4	0.05094856
GW	93	7	-5.5	4	-4	-5.5	8	-4	0.05094856
GW	96	7	-5.5	-8	-6	-5.5	-4	-6	0.05094856
GW	97	3	-5.5	-4	-6	-5.5	-4	-4	0.05094856
GW	98	3	-5.5	0	-4	-5.5	0	-6	0.05094856
GW	99	7	-5.5	0	-6	-5.5	-4	-6	0.05094856
GW	100	3	-5.5	4	-4	-5.5	4	-6	0.05094856
GW	101	7	-5.5	4	-6	-5.5	0	-6	0.05094856
GW	102	7	-5.5	4	-6	-5.5	8	-6	0.05094856
GW	105	7	-5.5	-8	-8	-5.5	-4	-8	0.05094856
GW	106	3	-5.5	-4	-8	-5.5	-4	-6	0.05094856
GW	107	3	-5.5	0	-6	-5.5	0	-8	0.05094856
GW	108	7	-5.5	0	-8	-5.5	-4	-8	0.05094856
GW	109	3	-5.5	4	-6	-5.5	4	-8	0.05094856
GW	110	7	-5.5	4	-8	-5.5	0	-8	0.05094856
GW	111	7	-5.5	4	-8	-5.5	8	-8	0.05094856
GW	114	7	-5.5	-8	-10	-5.5	-4	-10	0.05094856
GW	115	3	-5.5	-4	-10	-5.5	-4	-8	0.05094856
GW	116	3	-5.5	0	-8	-5.5	0	-10	0.05094856
GW	117	7	-5.5	0	-10	-5.5	-4	-10	0.05094856
GW	118	3	-5.5	4	-8	-5.5	4	-10	0.05094856
GW	119	7	-5.5	4	-10	-5.5	0	-10	0.05094856
GW	120	7	-5.5	4	-10	-5.5	8	-10	0.05094856
GW	123	7	-5.5	-8	-12	-5.5	-4	-12	0.05094856
GW	124	3	-5.5	-4	-12	-5.5	-4	-10	0.05094856
GW	125	3	-5.5	0	-10	-5.5	0	-12	0.05094856
GW	126	7	-5.5	0	-12	-5.5	-4	-12	0.05094856
GW	127	3	-5.5	4	-10	-5.5	4	-12	0.05094856
GW	128	7	-5.5	4	-12	-5.5	0	-12	0.05094856
GW	129	7	-5.5	4	-12	-5.5	8	-12	0.05094856
GW	204	3	-5.5	8	10	-5.5	8	12	0.05094856
GW	205	3	-5.5	8	8	-5.5	8	10	0.05094856
GW	206	3	-5.5	8	6	-5.5	8	8	0.05094856
GW	207	3	-5.5	8	4	-5.5	8	6	0.05094856
GW	208	3	-5.5	8	2	-5.5	8	4	0.05094856
GW	209	3	-5.5	8	-5.464e-15	-5.5	8	2	0.05094856
GW	210	3	-5.5	8	-2	-5.5	8	-5.464e-15	0.05094856
GW	211	3	-5.5	8	-4	-5.5	8	-2	0.05094856
GW	212	3	-5.5	8	-6	-5.5	8	-4	0.05094856
GW	213	3	-5.5	8	-8	-5.5	8	-6	0.05094856
GW	214	3	-5.5	8	-10	-5.5	8	-8	0.05094856
GW	215	3	-5.5	8	-12	-5.5	8	-10	0.05094856
GW	216	3	-5.5	-8	10	-5.5	-8	12	0.05094856
GW	217	3	-5.5	-8	8	-5.5	-8	10	0.05094856
GW	218	3	-5.5	-8	6	-5.5	-8	8	0.05094856
GW	219	3	-5.5	-8	4	-5.5	-8	6	0.05094856
GW	220	3	-5.5	-8	2	-5.5	-8	4	0.05094856
GW	221	3	-5.5	-8	-5.464e-15	-5.5	-8	2	0.05094856
GW	222	3	-5.5	-8	-2	-5.5	-8	-5.464e-15	0.05094856
GW	223	3	-5.5	-8	-4	-5.5	-8	-2	0.05094856
GW	224	3	-5.5	-8	-6	-5.5	-8	-4	0.05094856
GW	225	3	-5.5	-8	-8	-5.5	-8	-6	0.05094856
GW	226	3	-5.5	-8	-10	-5.5	-8	-8	0.05094856
GW	227	3	-5.5	-8	-12	-5.5	-8	-10	0.05094856
GS	0	0	0.0254		' All in in.
GE	0
EK
LD	5	0	0	0	5.8e7	0
EX	0	1	2	0	1	0
GN	-1
FR	0	1	0	0	500	0

Last edited by wildwillie; 2018-03-20 at 10:04 PM.
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post #2 of 35 (permalink) Old 2018-03-21, 11:47 AM Thread Starter
 
Join Date: Jan 2009
Posts: 443
SWR < 2. Gain 9 to 10 across the band , with a F/B > 25
Found one way to up gain , but one 1 db and I loose gain up in the upper band some
not a good way to make more gain .
Have not tried double down yet
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post #3 of 35 (permalink) Old 2018-03-21, 11:32 PM
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Join Date: Nov 2008
Location: San Diego, CA
Posts: 3,175
UHF_Quadruple_Quad_16x24_ScnGrid=2x4 by WildWillie

About 10 dBi Gain from 470-662 MHz...with notable Gain Roll-off to 7.8 dBi at 698 MHz...with good SWR and F/R=14.2-16.3 dB...very high F/R [directly opposite main beam]. High Freq Roll-off could be reduced to ~ 8.6 dBi, with slightly higher SWR on 470 MHz, by shifting Gain Curve by ~12 MHz [F = 0.982 Re-Scale].

EVAL RESULTS:

Code:
Input file : Z:\4nec2_PLUS\U\U - Quad-Quad - WW\
UHF_Quadruple_Quad_16x24_ScnGrid=2x4_WW.nec
Freq sweeps: [(278, 12, 61)]
Autosegmentation: NO

         --- Gain ---              -- Ratios -- -- Impedance --
   Freq    Raw    Net   SWR BeamW    F/R    F/B    Real    Imag  AGT  corr
==========================================================================
  350.0   9.41   1.22 24.31  70.7  14.81  14.81 3991.30-3624.71 1.00 -0.00
  362.0   9.49   2.58 17.57  71.0  16.30  16.30 1376.44-2301.26 1.00 -0.00
  374.0   9.57   3.82 12.95  71.1  17.86  17.86  775.70-1530.02 1.00 -0.00
  386.0   9.63   4.92  9.74  71.4  19.45  19.50  550.66-1110.43 1.00 -0.00
  398.0   9.69   5.88  7.48  71.5  18.80  21.33  442.12 -850.84 1.00  0.01
  410.0   9.75   6.73  5.86  71.8  18.22  23.43  381.91 -674.43 1.00  0.01
  422.0   9.80   7.44  4.68  72.0  17.70  25.98  345.53 -546.08 1.00  0.01
  434.0   9.84   8.03  3.81  72.2  17.23  29.26  322.33 -447.39 1.00  0.01
  446.0   9.84   8.49  3.15  72.4  16.77  32.76  307.50 -367.43 1.00  0.01
  458.0   9.83   8.86  2.61  72.4  16.42  32.83  299.72 -299.46 1.00  0.00

  470.0   9.78   9.13  2.19  72.4  16.26  30.42  299.64 -240.75 1.00  0.00
  482.0   9.75   9.33  1.86  72.3  16.22  29.21  306.65 -191.85 1.00  0.00
  494.0   9.77   9.50  1.64  72.3  16.20  29.35  317.88 -152.94 1.00  0.00
  506.0   9.83   9.66  1.49  72.3  16.12  30.36  330.75 -122.37 1.00  0.00
  518.0   9.89   9.77  1.40  72.4  15.97  31.89  344.22  -98.21 1.00  0.01
  530.0   9.96   9.86  1.35  72.6  15.78  33.71  358.12  -79.18 1.00  0.01
  542.0  10.04   9.95  1.34  72.7  15.58  35.62  372.47  -64.66 1.00  0.01
  554.0  10.11  10.01  1.35  72.9  15.37  37.25  387.19  -54.49 1.00  0.01
  566.0  10.17  10.06  1.38  73.1  15.17  38.08  402.04  -48.79 1.00  0.01
  578.0  10.25  10.12  1.43  73.3  14.98  37.93  416.51  -47.86 1.00 -0.01
  590.0  10.30  10.14  1.47  73.4  14.78  37.16  429.70  -52.09 1.00 -0.01
  602.0  10.32  10.13  1.52  73.6  14.58  36.21  440.19  -61.79 1.00 -0.01
  614.0  10.32  10.11  1.56  73.7  14.41  35.34  445.91  -76.78 1.00 -0.01
  626.0  10.28  10.04  1.60  73.7  14.26  34.60  444.28  -95.82 1.00 -0.01
  638.0  10.22   9.97  1.62  73.8  14.13  33.91  432.88 -116.01 0.98 -0.07
  650.0  10.02   9.77  1.63  73.6  14.04  33.15  410.84 -132.69 0.98 -0.07
  662.0   9.69   9.45  1.61  73.3  13.99  32.08  380.17 -140.69 0.98 -0.07
  674.0   9.21   9.00  1.56  73.0  14.00  30.50  345.83 -136.68 0.98 -0.07
  686.0   8.56   8.39  1.48  72.5  14.06  28.38  313.65 -120.82 0.98 -0.07
  698.0   7.82   7.70  1.39  71.9  14.21  25.99  287.82  -96.17 0.98 -0.09

  710.0   7.00   6.93  1.29  71.3  14.35  23.59  269.87  -66.73 0.98 -0.09
  722.0   6.23   6.19  1.21  70.6  14.45  21.40  259.29  -35.77 0.98 -0.09
  734.0   5.59   5.56  1.18  70.0  14.39  19.52  254.63   -5.25 0.98 -0.09
  746.0   5.12   5.08  1.20  69.0  14.11  17.96  254.36   23.96 0.98 -0.09
  758.0   4.76   4.70  1.27  68.8  13.75  16.65  257.21   51.61 0.99 -0.05
  770.0   4.54   4.44  1.36  68.8  13.30  15.49  262.05   78.05 0.99 -0.05
  782.0   4.39   4.23  1.46  69.6  12.93  14.47  268.45  104.20 0.99 -0.05
  794.0   4.27   4.05  1.58  71.1  12.50  13.65  277.17  130.39 0.99 -0.05
  806.0   4.13   3.83  1.69  72.2  11.91  12.90  287.88  155.90 0.99 -0.05

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

Last edited by holl_ands; 2018-03-22 at 12:42 AM.
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post #4 of 35 (permalink) Old 2018-03-22, 12:27 AM
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Location: San Diego, CA
Posts: 3,175
UHF_Quadruple_Quad_16x24_ScnGrid=1x2 Mod

What if change from 2"Hx4"W to 1"Hx2"W Grid Size??? NOT MUCH....

Negligible change to Gain and minor changes to SWR. Still see notable Gain Roll-off to 7.5 dBi at 698 MHz...with good SWR and about 1 dB increase in F/R...but significant reduction in F/R [directly opposite main beam]. And can no longer change High Freq Roll-off via Re-Scale due to slight increase in SWR on Low Freqs.

EVAL RESULTS:

Code:
  350.0   9.43   0.83 26.93  70.0  12.09  12.09 3987.94-4033.60 1.00 -0.01
  362.0   9.52   2.24 19.32  70.3  13.12  13.12 1281.39-2390.77 1.00 -0.01
  374.0   9.60   3.53 14.09  70.5  14.13  14.13  710.73-1556.68 1.00 -0.01
  386.0   9.68   4.71 10.44  70.7  15.13  15.13  503.12-1116.74 1.00 -0.01
  398.0   9.73   5.75  7.88  70.9  16.13  16.13  405.15 -847.68 1.00  0.01
  410.0   9.80   6.67  6.05  71.1  17.14  17.14  352.36 -665.77 1.00  0.01
  422.0   9.86   7.46  4.75  71.3  18.16  18.16  321.98 -533.89 1.00  0.01
  434.0   9.92   8.12  3.79  71.4  19.06  19.19  304.20 -433.21 1.00  0.01
  446.0   9.97   8.66  3.09  71.5  18.59  20.16  294.20 -353.06 1.00  0.01
  458.0  10.00   9.07  2.56  71.6  18.18  20.93  289.64 -286.81 1.00  0.01

  470.0  10.01   9.39  2.14  71.7  17.85  21.30  289.70 -230.21 1.00  0.01
  482.0  10.01   9.62  1.82  71.8  17.64  21.22  294.49 -180.98 1.00  0.01
  494.0  10.01   9.79  1.58  71.7  17.52  20.91  304.12 -138.47 1.00  0.01
  506.0  10.03   9.91  1.40  71.7  17.45  20.66  317.99 -102.78 1.00  0.01
  518.0  10.07  10.00  1.29  71.6  17.39  20.56  335.01  -73.89 1.00  0.01
  530.0  10.12  10.07  1.26  71.7  17.30  20.58  354.18  -51.45 1.00  0.01
  542.0  10.18  10.12  1.28  71.8  17.17  20.69  374.80  -35.14 1.00  0.01
  554.0  10.25  10.16  1.33  71.8  17.02  20.83  396.36  -24.88 1.00  0.01
  566.0  10.31  10.19  1.40  72.0  16.84  20.94  418.25  -20.92 1.00  0.01
  578.0  10.40  10.23  1.47  72.1  16.66  21.02  439.52  -23.77 1.00 -0.02
  590.0  10.45  10.24  1.54  72.2  16.48  21.02  458.64  -34.01 1.00 -0.02
  602.0  10.48  10.23  1.61  72.3  16.32  20.93  473.25  -51.90 1.00 -0.02
  614.0  10.47  10.19  1.67  72.4  16.15  20.73  480.08  -76.75 1.00 -0.02
  626.0  10.42  10.11  1.71  72.4  16.01  20.41  475.50 -105.91 1.00 -0.02
  638.0  10.35  10.02  1.73  72.4  15.88  19.94  456.91 -134.24 0.98 -0.08
  650.0  10.10   9.77  1.73  72.4  15.78  19.32  424.87 -154.77 0.98 -0.08
  662.0   9.71   9.41  1.70  72.2  15.74  18.56  384.29 -161.43 0.98 -0.08
  674.0   9.13   8.87  1.63  71.8  15.77  17.66  342.87 -152.12 0.98 -0.08
  686.0   8.37   8.17  1.53  71.2  15.92  16.67  307.50 -129.43 0.98 -0.08
  698.0   7.47   7.34  1.41  70.5  15.64  15.64  281.83  -98.51 0.98 -0.09

  710.0   6.53   6.45  1.29  69.8  14.70  14.70  266.14  -64.32 0.98 -0.09
  722.0   5.71   5.67  1.20  68.7  13.95  13.95  258.88  -30.26 0.98 -0.09
  734.0   5.11   5.08  1.16  67.6  13.44  13.44  257.93    1.97 0.98 -0.09
  746.0   4.76   4.72  1.19  67.7  13.18  13.18  261.51   31.64 0.98 -0.09
  758.0   4.58   4.52  1.27  67.7  13.10  13.10  268.08   58.84 0.99 -0.04
  770.0   4.57   4.47  1.35  68.0  13.08  13.08  276.69   83.96 0.99 -0.04
  782.0   4.61   4.46  1.44  68.6  13.06  13.06  286.74  107.44 0.99 -0.04
  794.0   4.67   4.47  1.54  69.1  12.99  12.99  297.90  129.81 0.99 -0.04
  806.0   4.71   4.44  1.64  69.5  12.84  12.84  309.99  151.53 0.99 -0.04

Antenna Simulations, Overload Calculations, etc: http://imageevent.com/holl_ands
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post #5 of 35 (permalink) Old 2018-03-22, 12:17 PM Thread Starter
 
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holl_ands on the 2"Hx4"W wire mesh as seen on some wifi antennas ,
I added another 2"Hx4"W 90 degree bend section on top and bottom
I lost some of the F/B ( have to readjust mesh spacing from elements to find sweat spot of better F/B)
brot up higher band near 698 end
I'm in the process of finding the sweat spot.
should beable to keep ohms near the 300 mark as it jumps up in the mid band just a little over 400 ( with some gain increase )

holl_ands RR material should be 16 W X 32 H or higher

holl_ands when you rescale you have to rescale RR mesh also . or try RR rods one behind each element. there is a sweat spot for them in length , your back spacing should be the distance of one element length or close to it , that's the starting point for RR material

RR material plays big part in swr and F/B

have to look at the VHF Hi to see were a good rescale factor would be for a good 10db across the band , I'm thinking of starting down in the 130mhz

Last edited by wildwillie; 2018-03-22 at 01:01 PM.
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post #6 of 35 (permalink) Old 2018-03-22, 01:06 PM Thread Starter
 
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holl_ands this 1"H x 4" W takes longer to compute lol what if you turn the 1x4 90 degree so its 4 x1 ?
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post #7 of 35 (permalink) Old 2018-03-22, 06:05 PM
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The Horizontal Wires are the important ones...cuz TV is mostly Horizontally Polarized.

I suppose I COULD do one more run...but NOTHING is going to be IMPROVED...so I'm going to decline, cuz my Laptop is busy on an OPTIMIZED, alternative Design.....which will likely take a day or two to finish up....

Antenna Simulations, Overload Calculations, etc: http://imageevent.com/holl_ands
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post #8 of 35 (permalink) Old 2018-03-22, 06:57 PM Thread Starter
 
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that's ok holl_ands thanks for testing , sure like to see what your working on when its done sir
I'm tring the 4x1 turned 90 degrees and cut down to a width of 12

now to find the F/B spacing
This QQ makes a good 10 db VHF Hi ,
just have to look at something
to see were, I want to start the model size at
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post #9 of 35 (permalink) Old 2018-03-22, 10:46 PM Thread Starter
 
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well holl_ands I decided to stack the antenna for a 12 to 13 db its running on the computer now
phase lines 1 inch out front
same feed gap 1.5 inches
spacing between the stacks 0.50 inches and it likes it.
AGT test at
470 12.5 db
632 13.4 db
698 10.5 db

the vertical beam is shrinking
horizontal is getting wider, 698 its really wide

I will figure this puppy out lol
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post #10 of 35 (permalink) Old 2018-03-24, 06:04 PM
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UHF Quadazoid Loop - No Refl

I immediately recognized that WildWillie's "Quad-Quad" [with all Dimensions Matchy-Matchy and NO GAPS other than the Feedpoint] had the SAME TOPOLOGY as the "Quad-Trap-Loop", except the latter has small GAPs at the Top and Bottom with OPTimized Free-Form Dimensions:
https://imageevent.com/holl_ands/loo...dtrapezoidloop
I also recognized that by adding a small GAP at the Top and Bottom of the "Twin-Loop" (aka Figure-8), the resultant "Chireix Loop" had significantly higher Gain....so I was curious to see whether or not the QTL outperformed a FREE-FORM "Quad-Quad"....which I have nicknamed the "Quadazoid-Loop (QZL)":
https://imageevent.com/holl_ands/loops

Hence, I decided to modify my FREE-FORM "Quad-Trap-Loop" Model with two more wires to close the Top and Bottom GAPs and ran it through nikiml's Optimizer to find the OPTimized Dimensions, resulting in the fol. 4nec2 Analysis of the "Quadazoid-Loop" [aka Gap-less Quadruple Trapezoid Loop]:
https://imageevent.com/holl_ands/loo...zoidloopnorefl

UHF Raw Gain = 6.3 to 7.4 to 6.2 dBi & SWR (300-ohms) Under 1.7....a bit LESS than QTL.
UHF Beamwidth = 82 to 72 degrees, Bi-Directional, decreasing with Freq, TIED with TWIN-LOOP.



So Quadazoid without Reflector falls in the middle of the pack wrt Gain:





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

Last edited by holl_ands; 2018-03-25 at 02:05 AM.
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post #11 of 35 (permalink) Old 2018-03-24, 06:21 PM
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UHF Quadazoid Loop + Reflector
Screen Grid Reflector = 24"H x 16"W with Grid = 2"H x 4"W:

I then added the SAME Reflector used by WildWillie in above Post#1 and RE-Optimized the "Quadazoid-Loop" Dimensions:
https://imageevent.com/holl_ands/loo...dazoidlooprefl

Note that OPTimized Dimensions WITH Reflector are somewhat DIFFERENT than without.
Most of this is due to the High Standard Deviation (Y2 Sigma = 0.87-in) in the Length
of the [8.37"] Horizontal Wire. [REDACTED: My comment re. Y2...it was an extraneous SYmbol problem...corrected Typo in 4nec2 File.]

UHF Raw Gain = 9.8 to 10.4 to 9.8 dBi, F/B & F/R Gain Min. = 14.1 dB
and SWR (300-ohms) Under 1.3...with Beamwidth ~ 70-deg.
So performance is very comparable to A-D C2, sacrificing High Gain in
order to provide a VERY WIDE BEAMWIDTH Azimuthal Pattern.






wildwillie likes this.

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Last edited by holl_ands; 2018-03-25 at 02:06 AM.
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post #12 of 35 (permalink) Old 2018-03-24, 07:34 PM Thread Starter
 
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You want to see that gain jump holl_ands
Add two 4 inch long 2x4 above and below to that reflector system , and ajust element spacing
Should run you up to the 750 MHz close to 9 db
470 to around 530 should hold 10 db
Then should raise to over 11 db then back down to around 10db at 698
F/b should drop at 470 and start to raise again mid band , stay stable then drop at 698
Well swr holds and you got a nice swr there sir
I'm just taking a wild what if , just looking at your data , that the above two pieces added to your RR system
Set element back one and half inches back from new RR ad on front opening of the new [
H Beam width should also widen and V beam width shrink

These types of antennas seem to love the top bottom coverage longer the better so far

I haven't even looked at your nec yet
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post #13 of 35 (permalink) Old 2018-03-24, 09:30 PM Thread Starter
 
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holl_ands have you looked into the M-Quad yet wow 19db claim gains and FB 40 db claims

with no REFLECTOR
I'm trying to figure out from I pic I just came across
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post #14 of 35 (permalink) Old 2018-03-24, 10:57 PM Thread Starter
 
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that quad quad in post one I did not clam it to be my design I just forgot to put nec model by me , the quad quad was just rescaled out of a pdf file I was reading , I liked the F/B they claimed that could be had. just seen it as a very easy build
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post #15 of 35 (permalink) Old 2018-03-25, 03:58 AM
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Re. Antennas with Very High F/B [narrow angle directly opposite Forward Beam]
and [More Importantly] Very High F/R [Worst Case for entire Rear Hemisphere]:


Since Interference and Multipath can be coming from ANY Direction, an Antenna with a High F/R is MUCH more useful than one that has a Deep Null directly towards the Rear but with significant Lobes towards other directions....and hence a much higher F/B Ratio....which is why my Performance Summaries cite the Minimum F/B Ratio. And I am NOT all that impressed by Very High F/R Ratio numbers....sure, you COULD use a Rotator to steer a Deep Rear Null towards a (single) source of Interference, but then it is very likely that there would be much less Gain toward the Desired Direction(s)....

Designing an Antenna with good Rear Cancellation is MUCH easier when trying to cover a Narrow Bandwidth (e.g. 2-m Band). I suspect, but have NOT yet determined whether the 2-m M-Quad Gain claim is an inflated number due to assuming a Mounting Height above a Ground Plane [vice usual Free Space]...as is implied in the fol. article:
https://www.google.com/url?sa=t&rct=...jDmVgiEKVE7KwZ

FYI: Although I wasn't TRYING to design an Antenna with a Very High F/B Ratio, the fol. Ch22 9-El FLF-Yagi [Flat Folded Loop] provided a 6 MHz Wide F/B Min = 40.2 dB....whereas for Full UHF Band Yagi's it takes many Directors and a Corner Reflector to barely reach F/B Min ~ 30 dB [although, again, I wasn't going out of my way to INTENTIONALLY Design a Very High F/B Antenna at the expense of some Forward Gain]:
https://imageevent.com/holl_ands/yag...9flfyagi300ohm
https://imageevent.com/holl_ands/yagis

For a Full Band UHF Antenna, it took far fewer LPDA Element Pairs to provide F/B Min ~ 20 dB than Elements in a Yagi...but ONLY when using an OPTIMIZER....K7MEM and LPCAD** programs were well off the mark:
https://imageevent.com/holl_ands/zigzaglpa/uhflpda

Going the next step and using a FREE FORM FLAT LPDA design reached F/B = 24.5 dB with only 7-El Pairs:
https://imageevent.com/holl_ands/zig...7elflatlpdaopt

I also analyzed simple Twin-Boom Sigma-Tau LPDA Designs for (nearly) all number of ODD Element Pairs from 3 thru 23. With 7-El Pairs, F/B Min = 20 to 25 dB, for Element/Boom thickness between AWG10 and 1/4-in O.D. And with 11-El Pairs, F/B Min = 28 to 32 dB....approaching a LIMIT of about 40-45 dB for a MUCH LARGER Number of Element Pairs. Downloadable Spread Sheet contains detailed Performance and Dimension information:
https://imageevent.com/holl_ands/zig...dawedgelayered

If you want a simple M4 4-Bay Bowtie with Very High F/B (and hence ALSO Very High F/R), Spacings between (Many) Reflector Rods needs to be about 1-inch for F/B Min ~ 25+ dB LIMIT [for that size Reflector....likely higher for Wider, Folded Reflector]:
https://photos.imageevent.com/holl_a...20UHF%20FR.jpg

And F/B Min ~ 25 dB LIMIT [for that size Reflector] was also found for (old) CM4228 at 1-in Vertical Grid Spacing...although F/R [but NOT F/B] could be pushed significantly higher at 0.5-in Spacing. I believe that this is also roughly true for other Multi-Bay Bowtie Antennas:
https://photos.imageevent.com/holl_a...B%20Ratios.jpg

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

Last edited by holl_ands; 2018-03-25 at 03:45 PM.
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