Modulation = Phase Coherent FSK Mark = 1200 Hz Space = 2200 Hz Answertone = 2025 Soft Carrier Turn Off = 900 Hz Reverse Channel = 387 Hz POTS Throughput: Main Channel Half Duplex 1200 bps Reverse Channel 5 bps 4W Leased Line Full Duplex Throughput = 1800 bps
Neither AMD or TI has not made a 202 chip for 8 or 9 years Duane >Ian, >The reference given was for the purpose to read about modulation and Mark and >space frequencies and not for design. >if any one wants to design that is a different story, > >AMD had a FSK chip few years ago AM 7910, > >Jan > > > >At 10:00 AM 4/30/99 -0700, you wrote: >>Jan, >> >>You are correct it is 1200 bps FSK, but also half duplex. >> >>In my opinion the 202 in the ARRL handbook will not function very well in a >>POTS connection. The TX/RX filtering is not adequate. If I remember >>correctly that example is intended to be used in RF transmissions of high >>speed RTTY. >> >>Duane >> >> >> >>>First of all the 202 modem is 1200bps FSK modem, >>>You can find a lot of information in ARRL amateur radio Handbook. >>>The modified version of 202 modem is used for Ham Radio packet operation. >>>Jan >>> >>> >>>At 07:59 AM 4/30/99 -0400, you wrote: >>>>From: "Ian Chapman" <ichap...@nortelnetworks.com> >>>> >>>>Hi, >>>> A friend of mine would like to know about the old data set 202. >>>>Often called the penny whistle modem. That's FSK 300 bit/sec originating >>>>and answering frequencies really antique stuff. The older ones had >acoustic >>>>data couplers. Any help I can dig up information for him would be greatly >>>>appreciated. >>>> >>>> Regards Ian. >>>> >>>> >>>> >>>Janusz Purwin >>>Xedia Corp >>>119 Russell St. >>>Littleton Ma 01460 >>>Tel 978-952-6000 ext 166 >>>Fax 978-952-6090 >>>email; pur...@xedia.com >> >Janusz Purwin >Xedia Corp >119 Russell St. >Littleton Ma 01460 >Tel 978-952-6000 ext 166 >Fax 978-952-6090 >email; pur...@xedia.com
