HORIZONTALLY POLARIZED OMNI COMPARISONS (490 MHz) [Ordered by Gmin in each Category.] 13-Apr-16 holl_ands A. TRUE OMNI: [Roughly EQUAL GAIN in ALL Directions, preferably less than +/- 1 db] Gmin Gmax SWR SWR Char. Elev. Null (dbi) (dbi) Min Max Imped. Depth A1 7-El Yagi (w. Refl) TRIAD Array 3.8 4.2 1.2 1.4 50-14.9 dbi El=-48-deg -20.6 dbi El=-58-deg A2 6-El Yagi (w. Refl) TRIAD Array 3.4 4.3 1.1 1.4 50-9.5 dbi El=-36-deg -17.2 dbi El=-50-deg -20.0 dbi El=-54-deg -18.0 dbi El=-56-deg A3 4-El Yagi (w. Refl) TRIAD Array 2.8 3.5 1.1 1.2 50 Not a Problem A4 5-El Yagi (w. Refl) TRIAD Array 2.8 3.4 1.1 1.2 50 Not a Problem A5 3-El Yagi (No Refl) TRIAD Array 2.2 3.1 1.2 1.2 50 Not a Problem A6 4-El Yagi (No Refl) TRIAD Array 2.2 2.9 1.1 1.2 50 Not a Problem A7 2-El Yagi (No Refl) TRIAD Array 2.2 2.8 1.4 1.6 50 Not a Problem A8 5-El Yagi (w. Refl) QUAD Array 2.0 2.6 1.1 1.7 50-20.2 dbi El=-48-deg SWRTooHigh -19.2 dbi El=-58-deg A9 6-El Yagi (w. Refl) QUAD Array 2.0 2.4 1.1 1.8 60-20.5 dbi El=-48-deg SWRTooHigh -19.4 dbi El=-58-deg A10 3-El Yagi (No Refl) TRIAD Array 1.8 2.6 1.3 1.4 50-18.4 dbi El=-44-deg A11 4-El Yagi (w. Refl) QUAD Array 1.6 2.2 1.2 1.4 50-17.4 dbi El=-24-deg -20.2 dbi El=-38-deg A12 2-El Yagi (w. Refl) TRIAD Array 1.5 2.3 ### 1.8 1.8 50-23.2 dbi El=-44-deg SWRTooHigh A13 7-El Yagi (w. Refl) QUAD Array 1.4 2.1 1.2 1.3 50-12.5 dbi El=-44-deg -15.4 dbi El=-56-deg A14 Triangle 3X Dipole TRIAD Array 1.3 1.5 1.2 1.2 200 Not a Problem 200-ohm bit better than 50-ohms 1.3 1.5 0.7 1.4 50 Not a Problem A15 Square 4X Dipole QUAD Array 1.1 1.6 4.7 4.7 50 Not a Problem
[Why better OMNI Pattern at 470 MHz???] SWR TooHigh
A. TRUE OMNI: [Continued] A16 4-El Yagi (No Refl) QUAD Array 0.9 2.7 1.2 1.3 50 Not a Problem [WHY WORSE????] [And Reversed Phase Elements on Opposite Antennas are MUCH WORSE.] A17 HALO Single Loop Gap = 5.00-in 0.2 1.0 6.1 6.2 200 Not a Problem Omni: Gap = T.B.D. ~0.9 ~1.5 TBD TBD TBD Not a Problem Quasi: Gap = 1.89-in -0.2 2.2 32.4 33.7 50 Not a Problem Quasi: Gap = 0.63-in -1.6 3.3 High High 2226 Not a Problem Need to Adjust Gap for Low SWR w. 50 or 200-ohm Load - But VERY CRITICAL Dimensions B. OMNI-PLUS: [Gain Greater Than Gmin in ALL Directions and PLUS that in SOME Directions] Gmin Gmax SWR SWR Char. Elev. Null (dbi) (dbi) Min Max Imped. Depth B1 Flat-Swept SBGH 7.2 9.3 1.4 1.4 200-23 dbi El=-38-deg B2 Swept FF4 7.1 7.9 1.2 1.8 200-26 dbi El=-40-deg SWRTooHigh -15 dbi El=-18-deg B3 Double ZZ8 (Similar to Swept SBGH) 6.8 9.3 1.2 1.3 200-26 dbi El=-18-deg -24 dbi El=-32-deg -22 dbi El=-62-deg B4 Hourglass-Loop TRIAD Array + FL's Down Angle = 0-deg El = 0 4.9 5.2 1.4 1.6 200-38 dbi El=-42-deg B5 QuadTrap-Loop+2Bars TRIAD Array + FL's SWR TooHigh Down Angle = 0-deg El = -2 3.9 5.4 2.8 4.0 200-24 dbi El=-28-deg Down Angle = 2.5-deg El = -2 3.6 5.2 2.8 4.0 200-24 dbi El=-30-deg Down Angle = 5-deg El = -2 3.6 5.2 2.8 4.0 200-15 dbi El=-36-deg Down Angle = 7.5-deg El = -2 1.5 3.3 2.8 4.0 200-14 dbi El=-42-deg [Down Angle = 5-deg is "Enough" to suppress Elev. Null.] C. QUASI-OMNI: [Gain Less than 0 dbd = 2.15 dbi in SOME or MANY Directions] C1 C2 Double Diamond Quad + 90-deg TL's 486 MHz 1.9 7.0 1.4 200 490 MHz 4.6 5.4 1.2 200-25 dbi El=-32-deg 494 MHz 2.4 6.7 1.1 200 Hourglass-Loop QUAD Array + FL's Down Angle = 2-deg El = 0-1.5 4.3 1.9 1.9 200 Not a Problem Down Angle = 2-deg El = -60-4.5-3.3 1.9 1.9 200 Not a Problem
[WHY OMNI GAIN LOSS & HIGH SWR??] SWR TooHigh C3 Double Hoop [FM Band Data] -1.8 1.2 ~1.2 ~2 50 Not a Problem [ReRun 490 MHz w. Variable Gap for Best SWR] SWR TooHigh C4 Swept FF2-8.5 5.3 2.9 2.9 200 T.B.D. SWR TooHigh
DVB-T Ch23 RANGE CALCULATOR Enter data ONLY into BLUE fields holl_ands 14-Apr-16 FSPL = 20*log(km) + 10*log(freq) +32.44 db [Free Space Path Loss] Normalized RX Power (dbm) = EIRP (dbm) - FSPL (db) "WORST" is for Antenna pointed in some OTHER direction and hence about 0 dbi Gain toward 490 MHz. Required PAL SNR = 25+ db Grade2 (Very Annoying), 30+ db Grade3 (Annoying) and??? db Grade 4 (Noticeable) and min. 43 db for IEC-728-1. Required DVB-T C/N (For 3/4 Code in 8 MHz) = 18.6 db (64QAM at 24.9 Mpbs), 13.0 db (16QAM at 16.6 Mbps) and 6.8 db (QPSK at 8.3 Mbps) For Ricean Channels, From http://amalia.img.lx.it.pt/~fp/cav/additional_material/terrestrial%20dvb%20%28dvb-t%29.pdf 3 DIPOLES IN TRIAD ARRAY: BEST TYPICAL WORST Xmtr Power (watts) = 0.35 0.35 0.35 watts Xmtr Power (dbm) = -4.6-4.6-4.6 dbm TX Cable Losses = 2.0 2.0 2.0 db (Need to Minimize Length of LOW LOSS Cable) TX Balun Loss = 0.5 0.5 0.5 db (Recommend Low Loss Coax 4:1 Balun) TX Antenna Gain (Min) = 1.3 1.3 1.3 db [MIN. FOR 3 DIPOLES IN TRIAD ARRAY] EIRP (dbm) = -5.8-5.8-5.8 dbm EIRP (watts) = 0.266 0.266 0.266 watts Max Range = 1.0 1.0 1.0 km Free Space Path Loss (db) = 86.3 86.3 86.3 db (For 1 km at 490 MHz) Normalized RX Power (dbm) = -92.0-92.0-92.0 dbm (For 0 dbi RX Antenna, No RX Losses) RX Antenna Gain = 15.0 10.0 0.0 dbi (0 dbi "Typical" when NOT pointed to Station) Balun + Cable Losses = 2.0 4.0 4.0 dbi RF Splitter Losses = 0.0 0.0 0.0 dbi RX Power at Tuner Input = -79.0-86.0-96.0 dbm (Preamp will improve on these numbers) Tuner NF = 6.0 6.0 6.0 db 7.6 MHz Noise Power at Tuner Input = -108.2-108.2-108.2 dbm CNR is about equal to SNR = 23.2 16.2 6.2 db [= Rx Power - NF + 108.2] Analog PAL"Suitability" = POOR NO NO DVB-T "Suitability" = GOOD FAIR POOR "Typical" DVB-T Rate Supported = 64-QAM 16-QAM QPSK "Typical" DVB-T CNR Required = 18.6 13.0 6.8 SNR Margin = 4.6 3.2-0.6
FLAT-SWEPT SBGH: BEST TYPICAL WORST Xmtr Power (watts) = 0.35 0.35 0.35 watts Xmtr Power (dbm) = -4.6-4.6-4.6 dbm TX Cable Losses = 2.0 2.0 2.0 db (Need to Minimize Length of LOW LOSS Cable) TX Balun Loss = 0.5 0.5 0.5 db (Recommend Low Loss Coax 4:1 Balun) TX Antenna Gain (Min) = 7.2 7.2 7.2 db [MIN. FOR FLAT-SWEPT SBGH] EIRP (dbm) = 0.1 0.1 0.1 dbm EIRP (watts) = 1.033 1.033 1.033 watts Max Range = 1.0 1.0 1.0 km Free Space Path Loss (db) = 86.3 86.3 86.3 db (For 490 MHz) Normalized RX Power (dbm) = -86.1-86.1-86.1 dbm (For 0 dbi RX Antenna, No RX Losses) RX Antenna Gain = 15.0 10.0 0.0 dbi (0 dbi "Typical" when NOT pointed to Station) Balun + Cable Losses = 2.0 4.0 4.0 dbi RF Splitter Losses = 0.0 0.0 0.0 dbi RX Power at Tuner Input = -73.1-80.1-90.1 dbm (Preamp will improve on these numbers) Tuner NF = 6.0 6.0 6.0 db 7.6 MHz Noise Power at Tuner Input = -108.2-108.2-108.2 dbm CNR is about equal to SNR = 29.1 22.1 12.1 db [= Rx Power - NF + 108.2] Analog PAL"Suitability" = GOOD POOR NO DVB-T "Suitability" = GOOD GOOD POOR "Typical" DVB-T Rate Supported = 64-QAM 64-QAM QPSK [Probably WORSE at some Locations] "Typical" DVB-T CNR Required = 18.6 18.6 6.8 SNR Margin = 10.5 3.5 5.3
ANTENNA LOOK DOWN ANGLE vs RANGE Angle = (180/3.14159)*ASIN(DeltaHt/1000*Range) 15-Feb-16 holl_ands TX Height Advantage (m)= 10 20 30 40 50 60 70 RANGE (km) = 0.01 90.00 0.02 30.00 90.00 #VALUE! #VALUE! 0.03 19.47 41.81 90.00 #VALUE! 0.04 14.48 30.00 48.59 90.00 0.05 11.54 23.58 36.87 53.13 90.00 #VALUE! #VALUE! 0.06 9.59 19.47 30.00 41.81 56.44 90.00 #VALUE! 0.07 8.21 16.60 25.38 34.85 45.59 59.00 90.00 0.08 7.18 14.48 22.03 30.00 38.68 48.59 61.05 0.09 6.38 12.84 19.47 26.39 33.75 41.81 51.06 0.1 5.74 11.54 17.46 23.58 30.00 36.87 44.43 0.15 3.82 7.66 11.54 15.47 19.47 23.58 27.82 0.2 2.87 5.74 8.63 11.54 14.48 17.46 20.49 0.3 1.91 3.82 5.74 7.66 9.59 11.54 13.49 0.4 1.43 2.87 4.30 5.74 7.18 8.63 10.08 0.5 1.15 2.29 3.44 4.59 5.74 6.89 8.05 0.6 0.96 1.91 2.87 3.82 4.78 5.74 6.70 0.7 0.82 1.64 2.46 3.28 4.10 4.92 5.74 0.8 0.72 1.43 2.15 2.87 3.58 4.30 5.02 0.9 0.64 1.27 1.91 2.55 3.18 3.82 4.46 1 0.57 1.15 1.72 2.29 2.87 3.44 4.01 LOOK-DOWN ANGLE: 0.1 5.74 11.54 17.46 23.58 30.00 36.87 44.43 LOOK-DOWN LOSS (db): 0.1-0.03-0.1-0.3-0.5-0.8-1.3-2.1 LOOK-DOWN LOSS + 20 db (PROPAGATION GAIN FOR 0.1 km vs 1.0 km): 0.1 19.97 19.9 19.7 19.5 19.2 18.7 17.9
80 90 100 90.00 #VALUE! #VALUE! 62.74 90.00 #VALUE! 53.13 64.16 90.00 32.23 36.87 41.81 23.58 26.74 30.00 15.47 17.46 19.47 11.54 13.00 14.48 9.21 10.37 11.54 7.66 8.63 9.59 6.56 7.39 8.21 5.74 6.46 7.18 5.10 5.74 6.38 4.59 5.16 5.74 53.13 64.16 90.00-3.2-5.8 16.8 14.2
3-Dipole Triangle - Look Down Angle vs Tower Height Advantage (meters) Advantage = 10-m Advantage = 20-m Advantage = 30-m Advantage = 40-m 90.00 Advantage = 60-m Advantage = 80-m Look Down Angle (degrees) 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 Loss = 10 db Loss = 6 db Loss = 3 db Loss = 2 db Loss = 1 db Loss = 0.5 db 0.00 0 0.05 0.1 Range (km) 0.15 0.2 0.25
Flat-Swept SBGH OMNI - Look Down Angle vs Tower Height Advantage (m) Advantage = 10-m Advantage = 20-m Advantage = 30-m Advantage = 40-m 70.00 Advantage = 60-m Advantage = 80-m Loss = 20 db 60.00 Look Down Angle (degrees) 50.00 40.00 30.00 20.00 Loss = 3 db 10.00 Loss = 1 db Loss = 12 db Loss = 30 db Loss = 20 db Loss = 16 db Loss = 20 db Loss = 10 db Loss = 6 db 0.00 0 0.05 0.1 0.15 0.2 Range 0.25 (km) 0.3 0.35 0.4 0.45 0.5