Originally posted by SteveHorn
Dennis, thanks for the preamp info. I looked at that site and the preamp I currently have from Hooper's (Winegard AP8275) specs out a bit better than the CM.
You are welcome, Steve...
I noticed the following when looking up the preamp specs:
Amp--------VHF Gain-----VHF Noise-----UHF Gain-----UHF Noise
CM 7777------23 dB--------2.8 dB-------26 dB--------2.0 dB
AP 8275------29 dB--------2.9 dB-------28 dB--------2.8 dB
In general, the gain provided by a preamp must only be enough to overcome transmission line losses and downstream splitter losses between it and the next active stage. The Winegard does provide considerably more gain at VHF, but unless you are overcoming huge downstream losses, it's probably not important. What may be more important is the UHF noise figure of the preamp. The 1st preamp's noise figure adds directly into the system noise figure, therefore while the VHF noise specs are virtually identical for the two amps, the CM has almost a dB less noise at UHF.
This is, of course, splitting hairs... Most TV receive systems don't run on 1 dB noise margins... I'm more acustomed to designing systems for satellite reception and for moon bounce reception... ;-)
Good luck!! (Picture quality on The Mummy Returns on ABC last night was great! The audio sync was still a tad off, but not enough to be a big bother.)