Message-Id: <20041024035433.XWAR22847.imf23aec.mail.bellsouth.net@[68.212.106.57]>

Dave wrote:
   >From what I understand about the 220/222MHZ band, it is divided
   >into 5KHZ channels.  The mode that is used for voice communications
   >is acsb (amplitude commanded single sideband).  Acsb is a standard
   >ssb signal that is compressed.  There is also a pilot tone inserted
   >3.1khz out from the ssb signal.  This enables the receiver to
   >frequency lock to the transmitted signal.  When a signal is
   >received the signal is expanded and demodulated like an ssb signal
   >with the pilot notched out.  When I lived in north Jersey in the
   >1990s there was a large acssb trunked system in the new York metro
   >area.
Yep, amplitude companded sideband.  IIRC there's a couple questions
about it in the extra question pool.
I'm surprised it hasn't caught on more than it has, the advantages of
sideband without the tuning problems for the average JOe radio user
who uses commercial type systems.

73 de nf5b



Richard Webb

Electric Spider Productions
almost 50% of those at ground zero on 9/11/01 still have
longterm health problems.  Almost half of those have no health insurance.