Low AGC on a yacht.



I'm new to the Sat TV world and need some info about the INA settings for Astra 2B around the Med. If anyone can recommend a website with good info about the frequencies and other settings I'd definitely appreciate it.
Currently we have onboard a SeaTel TAC92 receiver with a Model 3294 Antenna. At the moment we are in Genoa, Italy and scheduled to go down to Sardinia later this week.
The INA setting I'm using is 11046 which is giving me around 1024 AGC.
Last week up near Monaco the system died because of a bad Eprom chip and the tech who came out to repair the receiver reset the INA to 11055 and that gave us an AGC of 1260. Now 90 miles away from Monaco we are getting better AGC by using the INA of 11046, that is only giving us 1024 on the AGC. (The Skybox frequency is set at 12.266)
I think we can get better because some yachts are getting up around 1700 for their AGC. I'd really like to know how and why they are.
if anyone has any suggestions to improve this in different areas around the Med., I'd be grateful.
Thanks, Steve M.