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Originally Posted by Jon_
PM sent 
Since its been nearly 6 years since i did my a level in physics, is there a guide or something out there that would show me in more 2easy to understand" terms what the affect a 3.5db loss or the frequencies used and how they affect things, as atm those figures went totaly over my head! |
hehe most sacm's (stand alone cable modems) run on frequencies 402.775 mhz carrier and i think 411.000 for return path.
the level at which a modem operates correctly is about -1 dbv @ 402.775 and flat -0 dbv on 579.000 and 835.000 and about +12 dbv on 128.000 but not everyone's is set correctly. the tolerance is about 6 dbv - and about 4 dbv + on the 402.775....... lowest 128.000 can be is about +4 dbv
where as digital runs on a multiplex of signals...
128.000
579.000 (northants) 811.000 (Coventry) Default Freq
835.000 Return Path
411.000 carrier
and many more...
digital have to be as close to -0 dbv flat across the freq otherwise slope and gains will make it impossible to become 5 connected and then for interactive services to work, boxes freezing and jumping.. locking etc etc