Winegard YA-1713 modeled in 4nec2, based on actual measurements. Includes Max, Min & No Boom Corrections. Due to Gain degradation and wild SWR fluctuations, I used NO Boom Corrections in all other investigations.
UPDATE (5Jan2009): Crazy SWR behavior was due to error in 4nec2 file (need meters vice inches for Lc!!!). Also double checked antenna physical measurements--a few changed a couple sixteenths. Revised runs show only small Gain & SWR differences after apply BoomCorr. Excessive SWR will severely degrade Net Gain. [Note that Gain in SWEEPER is incorrect...see "Pattern" box for value.]
Date(s): 5Jan2009 UPDATE. Album by holl_ands. 1 - 16 of 16 Total. 3101 Visits.
enlarge 25KB, 800x789 1 YA-1713 in 4nec2 - 3D View
enlarge 58KB, 800x342 2 YA-1713 in 4nec2 - Top View
enlarge 38KB, 800x264 3 YA-1713 in Real Life - Top View
Keep clicking on image to see higher rez versions. Click on "X" as usual to exit window.
enlarge 149KB, 800x640 4 YA-1713 - Aluminum Elements - Gain No Boom Correction
Raw Gain at 213 MHz = +5.44 dBi (Center of Ch13) Raw Gain at 216 MHz = -2.37 dBi (Top of Ch13)
enlarge 156KB, 800x640 5 YA-1713 - Aluminum Elements - SWR No Boom Correction
Very Poor SWR vs Frequency
enlarge 143KB, 800x640 6 YA-1713 - Aluminum Elements - Impedance No Boom Correction
enlarge 162KB, 800x640 10 YA-1713c Boom Corrections per VK2KU's Article in Jan2000 QEX, derated 50% for mounting on Top vice Thru Boom. [Sweeper Gain is incorrect.] Sweep Crossover Transmission Feedline between Third and Second Elements to find Optimum Zc = 225-ohm.
enlarge 151KB, 800x640 11 YA-1713c Boom Corrections per VK2KU's Article in Jan2000 QEX, derated 50% for mounting on Top vice Thru Boom - Gain. Due to excessive SWR: Net Gain at 174 MHz is -4.8 dBi Net Gain at 198 MHz is -3.6 dBi Net Gain at 213 MHz is -5.7 dBi Net Gain at 216 MHz is -3.7 dBi
enlarge 155KB, 800x640 12 YA-1713c Boom Corrections per VK2KU's Article in Jan2000 QEX, derated 50% for mounting on Top vice Thru Boom - SWR. Due to excessive SWR: Raw Gain at 174 MHz is 10.4 dBi Raw Gain at 198 MHz is 12.5 dBi Raw Gain at 213 MHz is 4.5 dBi Raw Gain at 216 MHz is 4.5 dBi
enlarge 145KB, 800x640 13 YA-1713c Boom Corrections per VK2KU's Article in Jan2000 QEX, derated 50% for mounting on Top vice Thru Boom - Impedance.
For Lc=0.33 meters & Optimum Zc=225-ohms.
enlarge 150KB, 800x640 14 YA-1713c Boom Corrections per DL6WU's Formula with NO derating (worst case) - Gain Due to excessive SWR: Raw Gain at 174 MHz is 10.6 dBi Raw Gain at 198 MHz is 12.6 dBi Raw Gain at 213 MHz is 1.3 dBi Raw Gain at 216 MHz is -2.31 dBi
enlarge 156KB, 800x640 15 YA-1713c Boom Corrections per DL6WU's Formula with NO derating (worst case) - SWR Due to excessive SWR: Net Gain at 174 MHz is -4.7 dBi Net Gain at 198 MHz is -3.8 dBi Net Gain at 213 MHz is -4.7 dBi Net Gain at 216 MHz is -3.8 dBi
enlarge 145KB, 800x640 16 YA-1713c Boom Corrections per DL6WU's Formula with NO derating (worst case) - Impedance
Thanks Holl_ands, for your detailed analysis of the YA-1713.
Read your field test showing no apparent gain loss on channel 13.
Interesting how your improved model definiton doesn't seem to resolve the channel 13 simulation enigma.
Wonder how well the analysis software would model the Antennacraft Y10-7-13 or other similar antenna. Since the Antennacraft version seems to be a pure Yagi versus the YA-1713, a log-Yagi. The analysis differences or similarities could reveal whether the NEC antenna modeling software is robust or just simply breaks when near antenna band edges.
A: Y10-7-13 is ACTUALLY a DUAL-DRIVE Type(NO Crossover in the Interconnect) with DIFFERENT Spacing. -holl_ands - iMike Cooper, Tue, 22 Sep 2009 3:10PM
