Well at least if it is Flex system on a national carrier this is probably true... Some of the older systems at 900 like ours, which is POCSAG uses disciplined oscillators locked to the master which may or may not be on exact freq as it IS set and stable but not by GPS.... Freq error is measured by the diagnostic subsystem, but corrections are relative to the master freq of the main site test receiver...so they are all locked together wherever that is.... :-)
Doug KD8B At 12:05 PM 9/19/2007, you wrote: >Ken Arck wrote: > > At 04:29 PM 9/18/2007, you wrote: > > > >> Your local NOAA Weather station is a good test transmitter for frequency > >> and peak deviation.. Steve NU5D > > > > <---I disagree. I have seen MANY NOAA WX transmitters off-freq - some > > well outside tolerance. Usually however, (while their audio quality > > is overdriven, distorted and generally pure crapola), their deviation > > *is* within limits. > > > > Ken > >Agreed. Look at 900 Mhz paging (NOT VHF/UHF). Most of it is GPS sync'd, >so it's more 'on-freq' then even the ultra-high stability service >monitors. And deviation is usually pretty accurate, too-swings of either >+/-4.5 or 4.8 are the norm, depending on if it's in FLEX or POCSAG/Golay. > >-- >Jim Barbour >WD8CHL
