Hi-VHF+UHF 2-Bay + Rectangular Loop, RLH2 (12x10) with NO Reflector analyzed using 4nec2 after determining Dimensions using nikiml's Python Optimization Scripts. Rectangular Loop Resonator improves Hi-VHF Gain and SWR. Loop Diameter of 3/4-in was assumed for this initial Optimization, but is NOT critical. SWR in Hi-VHF Band remains under 2.7 for 1/4-in O.D. (or larger) and climbs to only 2.9 with AWG10. And at 698 MHz, SWR climbs from 2.7 to 2.8 if only 1/4-in O.D. and 2.9 if use as small as AWG10.
RLH2 (12.0x10.0): Re-Optimized 2-Bay plus Rectangular Loop, with 0.5-in Offset (Forward) to avoid wire collisions. Nikiml's Python Optimization Scripts determined that a 2-Bay (12.0x10.0) provides the BEST overall performance with significantly higher UHF Raw Gain than the two alternates above and lowest SWR in both UHF and Hi-VHF Bands.
UHF Raw Gain = 8.0-8.9-7.8-8.5-8.0 dBi or 8.3 dBi +/- 0.5 dB [INCREASE of 2.3 dB on low freqs & DECREASE of 1.2 dB on high freqs, providing a MUCH Flatter Frequency Response] and SWR (300-ohms) under 3.1 (FAIR). Hi-VHF Raw Gain = 3.9 to 4.3 dBi [INCREASE of 1.9 to 1.8 dB] and SWR (300-ohms) under 2.3 [EXCELLENT].
Date(s): 12 Feb 2015. Album by holl_ands. 1 - 19 of 19 Total. 4779 Visits.
enlarge 61KB, 598x1024 1 RLH2-Bay (12.0x10.0) + Rectangular Loop Front View 3D View
enlarge 307KB, 993x1024 2 RLH2-Bay (12.0x10.0) + Rectangular Loop Front View - 0.5-in Between 2-Bay & Loop Loop is about 26.75-in H x 21.0-in W Feedline Separation is about 4.5-in Tine Separation is about 6.25-in [1 large square = 2.5 inches]
enlarge 85KB, 289x1024 3 RLH2-Bay (12.0x10.0) + Rectangular Loop Top View - 0.5-in Between 2-Bay & Loop [1 large square = 2.5 inches]
enlarge 169KB, 1024x677 4 RLH2-Bay (12.0x10.0) + Rectangular Loop UHF Raw Gain = 8.0-8.8-7.8-8.4-7.9 dBi or 8.3 dBi +/- 0.5 dB
enlarge 236KB, 1024x696 19 M2 vs H2 vs RLH2 Comparison - No Refl Raw Gain H2 is Significant Improvement vs mclapp M2 RLH2's Hi-VHF Resonator Loop provides acceptable Hi-VHF SWR at expense of lower Gain on Upper Channels