Thread: Rca ant751
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Old 21-May-2017, 2:24 AM   #46
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,551
The next test that I did was to compare the GE PRO, ANT 751R, and the ANT 7511.

Relative Gain Comparison of three Antennas

Channel  GE PRO     RCA       RCA
          29884   ANT751R   ANT7511
          dBmV     dBmV      dBmV

15       -10.2    -12.5     -15.6
28       -10.4    -11.6     -13.4
39       -12.0    -12.3     -16.3

Equipment Used:
Antennas Direct DB2E source antenna
3 antennas to be compared
Blonder Tongue HAVM-1UA Agile Modulator
20 dB attenuator to reduce HAVM output
Sadelco DisplayMax 800 Signal Level Meter

Test Conditions:
Indoor Test Range; ground floor, carpet over concrete slab
Antennas 10 wavelengths apart
Antennas elevated on Table-Mate tables
Signal Level Meter measuring analog video carrier

The GE PRO 29884 antenna is the best of the 3 antennas for my indoor location. The RCA ANT 751R is a close second. The RCA ANT 7511 is third. The RCA design change has sacrificed considerable UHF gain.

I have a little more confidence in these measurements, but there are reflections that will introduce errors. I miss my outdoor range with stable LOS signals.

I'm fascinated by your test equipment!
So am I. Making antenna measurements is one of my favorite things.

You don't need a lot of expensive equipment. With just a variable attenuator and a TV, you can measure margin to dropout of the signal. The simplified form is shown in my signature link.

If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 21-May-2017 at 3:03 AM.
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