Technical information

P
2FWREHU 7KH8UEDQ';·HU
700 WLW Cincinnati, OH
740 CBL Toronto, Canada
750 WSB Atlanta, GA
760 WJR Detroit, MI
780 WBBM Chicago, IL
800 CKLW Windsor, Ontario (Talk Format)
800 PJB Bonaire, Netherlands Antilles (Religious Format)
810 WGY Schenectady, NY
830 WCCO Minneapolis, MN
840 WHAS Louisville, KY
850 WHDH Boston, MA
870 WWL New Orleans, LA
900 CHML Hamilton, Ontario
1000 WLUP Chicago, IL (ex WCCO)
1020 KDKA Pittsburgh, PA
1020 * CCR Caribbean Christian Radio - Turks & Caicos Islands
1040 WHO Des Moines, IA
1080 WTIC Hartford, CT
1090 WBAL Baltimore, MD
1100 WWWE Cleveland, OH (ID’s as “3WE”)
1110 WBT Charlotte, NC (Talk Format)
CKTY Sarnia, Ontario (C&W Format)
1160 WJJD Chicago, IL
1500 WTOP Washington DC
NFM DISCRIMINATOR CHIPS - BASEBAND AUDIO - SQUELCH GATE DATA
There is a growing interest in tapping the baseband audio out of various scanners for decoding of a variety of
esoteric
signals, including CTCSS, SCA, FSK, RTTY, FAX, etc. By and large, such signals cannot be taken from
TAPE REC jacks, headphone jacks, and EXT SPEAKER jacks because of the voice-band filtering that is done
between the signal source and these output jacks.
Therefore, it is necessary to tap the "baseband audio" directly at the output of the discriminator chip for your
scanner. Table 1 shows a list of scanners, the discriminator chip(s) used in the scanner, circuit symbols of
those chips, and three pins of general interest on the chips: RF-Input, Scan Control, and, of course, the
baseband audio (discriminator output) pin.
Even though your scanner may not be listed below, try to find its discriminator chip, and chances are it will be
listed with
one or more scanners below, the pins of which will be the same for your unlisted scanner! Corrections and
additions to this list are requested. See my mail and other addresses at the end of this file.
For hookup information, see just below Table 1.
TABLE 1: SCANNER DISCRIMINATOR CHIP PINS OF INTEREST
SCANNER NFM IC TYPE PART ID RF IN PIN SCAN PIN # BASEBAND AUDIO
MPS5071 n/a 16 13 9
AR-1000 TA-7787AF IC-4 16 none 9
AR-2002 MC-3357PIC-4 16 13 9
AR-2500 TA-7761P IC-13 16 9 ?