tom@uofm-cv.UUCP (Tom Libert) (09/22/83)
I'm interested in connecting a device directly to the telephone line. I know about FCC part 68, and I'm curious about what steps (if any) a ham/hobbyist must take in order to receive the phone company's blessing prior to installing a phone patch. In addition, I'd appreciate any pointers/references/ correspondence concerning the general design of phone patches (a.k.a. Direct Access Arrangements). Does it make any sense to design your own? If not, who makes good patches and how much do they cost? My application involves a speech synthesizer together with a DTMF encoder and a decoder, controlled by a microprocessor. The chips are as follows: Chip Description Manufacturer ---- ----------- ------------ SC01A Phoneme-oriented speech synthesizer Votrax 5089 DTMF encoder Mostek (among others) 203-P DTMF decoder Silicon Systems, Inc. I have discovered very few references so far; these have been helpful: Kuecken, John A., "Talking Computers and Telecommunications", Van Nostrand Reinhold, New York NY, 1983 Members of the Technical Staff of Bell Laboratories, "Engineering and Operations in the Bell System", 1977 Eisenberg, Albert J., "Telephone Coupling Transformers for Interconnect of Voice/Data Modem Terminals", Engineering Application Bulletin F232, Microtran Company, Inc., 145 E. Mineola Ave., Valley Stream NY 11582, 1977. Kuecken's book contains a wealth of useful information concerning recognition of ring signal, dial tone, busy signal, etc. Finally, there are many direct-connect modems currently on the market. Each one of them must contain an FCC-approved telephone interface. Does anyone have a schematic for any of these modems?