AST RESEARCH TECHNICAL BULLETIN TB-0170                   4-25-86


                    REACH! MODEM INTERFERENCE


Some  REACH!  modem users have experienced interference  problems 
when dailing numbers with the REACH! modem.  

These  customers receive broadcasts of AM radio stations  through 
the  REACH!  speaker as the modem is dialing a telephone  number.  

They  are located within a few miles of the interfering  stations 
transmitter  tower.   This close proximity to the transmitter  is 
causing the audio circuits of the REACH!  modem to be overdriven, 
which  demodulates  the RF signal,  which then plays  it  through 
REACH!'s speaker.

To  remove the interference,  it is necessary to acquire a  rapid 
interference  filter  such  as is sold by  AT&T  in  their  phone 
centers.  The part number for AT&T's filter is #Z100A.