AN~PRC-174

Control Connector Pinouts

All BCD levels for frequency control are 12v high to enable that digit.

61 Pin Israeli Connector (Small or Hex)

1 - X23 1khz BCD8

2 - X50 1mhz BCD1

3 - X30 10khz BCD1

4 - X11 100hz BCD2

5 - X10 100hz BCD1

6 - X22 1khz BCD4

7 - X43 100khz BCD8

8 - REM CONT (ground to enable remote control)

9 - N/C

10 - X51 1mhz BCD2

11 - X31 10khz BCD2

12 - X12 100khz BCD4

13 - IND (high to enable indicator functions)

14 - GND

15 - VOL REMOTE (remote volume control)

16 - BAT IN (battery pack in, might be able to charge with this pin)

17 - X21 1khz BCD2

18 - X42 100khz BCD4

19 - TRANSIT (pulse when 10mhz, 1mhz, 100khz or 10khz are changed)

20 - NCW (high when narrow CW is selected)

21 - WCW (high when wide CW is selected)

22 - DATA (high when data is selected)

23 - 12V REM (12 volts when remote is selected)

24 - X52 1mhz BCD4

25 - X32 10khz BCD4

26 - X13 100hz BCD8

27 - BATT CHK (high to enable battery check and LED display)

28 - TX LEVEL (high to enable power our and LED display)

29 - TUNE (high when radio is tuning)

30 - FO UNLOCK (high when synthesizer is unlocked)

31 - N/C

32 - S METER (analog RSSI)

33 - DIP (high when radio on dipole, low when on whip)

34 - X20 1khz BCD1

35 - X41 100khz BCD2

36 - X60 1mhz BCD1

37 - AM (high to enable AM mode)

38 - OFF (LOW when off – 24v when hi, caution)

39 - ON (LOW when on – 24v when hi, caution)

40 - USB (LOW when on USB, 12v when hi)

41 - R/T (LOW when tx enabled, 12v when hi)

42 - SSB (high to enable SSB mode)

43 - N/C

44 - X53 1mhz BCD8

45 - X33 10khz BCD8

46 - N/C – book says N/C but had some kind of pulsing on it

47 - SAVE/SQUELCH (hi batt save mode on 174, squelch mode on 174S)

48 - NO MATCH (high when no match found)

49 - MIC GND

50 - MIC HI

51 - PHONE (handset rx audio)

52 - PTT

53 - +12V

54 - ALC (not sure about this one...)

55 - PTT 12V

56 - BP (PA) (ground to bypass PA when using external amp, 100mw out)

57 - FIXED AUDIO (100mv fixed audio)

58 - X40 100khz BCD1

59 - X61 1mhz BCD2

60 - N/C – book says N/C but had some kind of pulsing on it

61 - LT (M.N. BP) matching network bypass

66 Pin Round connector, add these pins

62 - SQUELCH

63 - N/C

64 - N/C

65 - MIC

66 - GND

Related Files

OM-107-10

Technical Manual

Radio Set

PRC-174

August 1976

MA(P)-2124-09514-00

ILLUSTRATED PARTS BREAKDOWN

HF-SS r. RADIO SET

RT 936/PRC as174

January 1987

MA 2124-09503-00

Maintenance Manual

HF-SSB RADIO SET

PRC-174

July 1986