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Old 6-Jul-2016, 3:30 PM   #102
tripelo
Senior Member
 
Join Date: Jan 2010
Location: Dallas, TX
Posts: 123
Compare: Antennas Direct C5 & Televes Yagi B-III

A series of antenna tests conducted on July 1, 2016.

Objective: Compare performance of selected VHF antennas while receiving DFW TV channels

Antennas:

1. Antennas Direct C5
2. Televes Band III Yagi

Antennas Direct C5: Driven element is a loop design (contains two loops, inner and outer) with reflector screen. The balun is ferrite core design.

Televes Band III Yagi: Folded-dipole driven element with reflector and five directors. The balun is sealed in metal can.

Images of antennas shown below:

Antennas Direct ClearStream 5 (C5)




Televes Yagi B-III





Test Location:

Garland, TX, ~30 miles line-of-sight to DFW stations, both VHF channels (8 and 9) located on same transmitting tower.

Test location TVfool info posted earlier:

Compare Preamplifiers - Test Procedure & Configuration

Test Equipment:

Same as previous*, except:

1. Sencore SLM1456CM instead of Sencore SLM1456
2. 3dB attenuator at input of Sencore SLM1456CM
(From antenna perspective, improves coax cable match to 75 Ohms)


*Previous similar test: Compare Received Signal Strength of 5 UHF Antennas

Test Procedure

1. Calibrate VNWA, with the 40’coax cable (refers measurements to antenna/balun connection).

Starting with Antennas Direct ClearStream 5 antenna:

2. Mount antenna w/coax and ferrites to mast, raise center of antenna to 25 feet
3. Align antenna for peak signal on Channel 8
4. With 1456CM scan DFW VHF stations (Channels 8 & 9) for signal strength and MER.
(repeat scan 9 times while in this configuration, record times).
5. Take at least 2 Photos
6. Turn antenna ~90 degrees, disconnect coax from 1456, connect to VNWA
7. Measure S11 (input impedance, SWR/Return Loss) for the band
8. Lower Mast remove antenna
9. Mount Televes Yagi B-III, repeat steps 2-8
10. Then again, for each antenna, repeat steps 2-9


The test location and setup was similar to that described in previous posts:

Televes DAT-75 vs. Antennas Direct 91XG


Credit:

Thanks to Stuart Sweet of Solid signal for providing the Televes Yagi B-III.

(To be continued)

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Attached Images
File Type: jpg Antennas Direct ClearStream 5.jpg (60.3 KB, 3337 views)
File Type: jpg Televes Yagi B-III.jpg (26.5 KB, 3187 views)
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