parnass@ihu1h.UUCP (Bob Parnass, AJ9S) (10/16/85)
> In article <1173@mhuxt.UUCP> rma@mhuxt.UUCP (ATKINS) writes: > >Does anyone have, or know of, a source of information > >on Stereo TV decoding. I have a VCR with a "MPX out" > >jack which presumably outputs the encoded stereo signal. > >On a scope it seems to put out a ~70kHz carrier with some > >type of audio modulation when tuned to WNBC (NY) which I > >believe transmits stereo program material at times. Is the > >encoding similar to FM radio and is there a one chip decoder > >available? Subcarrier Transmissions Noted in the NY/NJ Area On a trip to the northern New Jersey area, a friend and I did some subcarrier listening by connecting the antenna jack of a Yaesu FRG7700 receiver to the audio stage of a cheap television set: - By tuning the Yaesu to 88.0 kHz FM, and the TV to channel 4, WNBC-TV New York was heard rebroadcas- ting WYNY-FM audio. WYNY is an NBC affiliate sta- tion. - By tuning the Yaesu to 31.5 kHZ USB, and the TV to channel 68, the audio of WWHT-TV Newark, a scram- bled TV station, was monitored. Other signals were heard, including a series of 6 or 7 telemetering tones sent every 30 seconds on an FM sub- carrier of a TV station. Several FM broadcast stations in the New York area were also using subcarrier technology. One station was transmitting 3 different subcarrier channels of infor- mation concurrently. -- =============================================================================== Bob Parnass, Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414