AP-8700 expected improvement in gain?

[ssheriff]

I installed an AP-8700 at the antenna hoping to get more stable reception of a couple channels that come and go. On average the SNR gain reported by my Samsung PN50C550 does not change with or without the AP-8700 preamplifier. For three channels, the before/after SNR gains are:
channel 13-1, 17.4dB/16.9dB
channel 8-1, 17.9dB/18.9dB
channel 11-3, 29.5dB/29.0dB

I expected these numbers to increase. Are my expectations wrong or is something else wrong?

[winegard]

Good afternoon ssheriff,

The AP-8700 preamplifiers noise figure only 2.8dB so it will not change your SNR that much. The SNR meter in the Samsung TV set does not read the actual RF voltage of the TV signal at the TV set and that is what you are actually changing with the gain of the AP-8700. As long as your pictures improved or you did not loose any channels the AP-8700 preamplifier is working.