I decided to do my own test. I don't have a spectrum analyzer but I do have a Winegard SensarPro. The SensarPro is an adjustable 10db gain amp with a digital display that can display channel and signal strength. I don't know what units are displayed for signal strength but it will give a relative comparison.
The test:
Location: Minneapolis/St. Paul
Heading: 090 true
Distance to transmitters: 12.46 miles
The antennas:
1. Jack
2. Bat1 - Amplified Batwing with Wingman
3. Bat2 - Non-amplified Batwing with Wingman
For the Jack and Bat1 antennas the SensarPro was set for .5db gain (its lowest setting).
The SensarPro gain was set for 10db for the Bat2 antenna (I'm assuming the Bat1 antenna has a 10db amp).
Each antenna was installed on my RV mast so each test was at the identical location and height.
| Jack | Bat1 | Bat2
-----|------|------|-----
Chnl | SS | SS | SS
-----|------|------|-----
9 | 48 | 51 | 56
11 | 42 | 47 | 52
22 | 66 | 58 | 63
23 | 52 | 47 | 50
29 | 57 | 54 | 57
32 | 57 | 48 | 49
34 | 48 | 45 | 48
35 | 55 | 42 | 47
45 | 58 | 44 | 56
-------------------------
Edit: My columns get buggered on posting. The columns start with channel number then followed by signal strength for each antenna.
My results seem to counter Jeff's. I think more tests are needed to make a definite conclusion.
