Hope this helps
See is this helps you de-mystify.
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Pin No. Symbol Description / Usage
1 NC No connection
2 TXD Serial data output (RS‐232C interface built‐in)
3 RXD Serial data input (RS‐232C interface built‐in)
4 RTS RTS signal input for internal RS‐232C interface
5 CTS CTS signal input for internal RS‐232C interface
6 Connected with Pin20
7 GND Ground
8 EXMOD External modulation input (Solder Bead "N"). NOTE: This is NOT MIC LEVEL.
Input impedance : approx. 27k ohms
Approx. 60% modulation (3kHz@ 1kHz tone) with 170mVrms input (480mvp‐p)
Note: in later SN F6061 radios, bead T will need to be cut as described in Technical Bulletin, kbase number C7A9111737
9 DISC Actual fixed level filtered audio. Bandpassed at 300 to 4kHz and de‐empahasized ohms Demodulated signal output. Output impedance : approx. 10k
300mVrms when receiving 60% modulated signal
Detected Detected Audio‐ Cut K and Solder L
10 HORNO Output for horn switching signal (5mA max)
OFF = H (When ON, input current must be lower than 50mA)
11 VCC Voltage output (max current : 100mA). Activated when the radio is turn ON.
12 MMUTI Input for MIC mute signal (5mA max)
13 NC No connection
14 GND Ground
DB25 Pin assignment for IC-F5061 / IC-F6061
15 PGI1 Programmable Pin ‐ Program in Key and Display at OPF0 (5mA max).
16 NC No connection (grounded with 47pF)
17 BUSY Busy signal‐ Output is Low (near Ground)=when receiving CARRIER signal (5mA max).
18 COR Digital Audible: Output for digital unmute signal (conventional and trunking) 5V= mute, 0V= unmute. (5mA max)
19 EPTTO PTT signal input
20 Connected with Pin6
21 AUD Analog Audible: Output for analog Auduble 5V= mute, 0V= unmute (5mA max).
22 PA AF amp output Impedance : approx. 10k ohms. Note: This is HIGH IMPEDENCE.
Output Level‐0 to 2V PP Volume Knob controlled.
Program RX speaker = ON : Output level follows AF VR knob condition (remove Q45 for "always on")
PA = ON : Output level varies by pressing UP/DN keys
23 MMUTO Output for internal MIC mute condition signal (5mA max).
24 DIMO Dimmer control input (LCS backlight control)
Input voltage to activate Range : +5 to +30V (5mA max).
25 HANGO Microphone hanger condition signal L= On‐hook (5mA max).
NOTE: All I/O lines are logic 0/5v state, with maximum current 5mA.
Coffee beans “A” Close When cut, this routes mic audio to J1 option
connector. (Note: cut this when installing UT-109 or
UT-110)
Coffee beans “B” Close When cut, this routes receive audio through J1 option
connector. (Note: cut this when installing UT-109 or
UT-110)
Coffee beans “C” Close When cut, this enables PTT control from option unit
on J1.
Coffee beans “D” Open When connected, it routes external audio (SPIN) from
D-SUB (J602) to the transmit modulating circuit
Coffee beans “E” Close When cut, this isolates external transmit audio
(SIGO) on J1 option connector from the transmit
modulation circuit
Coffee beans “F” Open When connected, it routes external transmit audio,
pin 8 on D-SUB connector (J602) to the VCO
modulating circuit.
Coffee beans “G” Close When cut, this isolates the output on buffer Q49 from
the AFO signals on the mic jack (J503) (Note: this
modification requires closing coffee beans“H” below.)
Coffee beans “H” Open When connected, this routes audio output signals on
IC21 to AFO on the mic jack. (Note: this modification
requires cutting coffee beans“G” above).
Coffee beans “I” Close When cut, this isolates demodulator signals (AFOUT)
on J1 option connecter from the audio processor (pin
19 of IC2).
Coffee beans “J” Open When connected, this routes the demodulator signal
(AFOUT) on the J1 option connector to discriminator
signals (DISC)
Coffee beans “K” Close When cut, this isolates the audio processor’s
demodulator output (pin 18 of IC2) from
discriminator signals (DISC) on the J1 option
connector.
Coffee beans “L” Open When connected, this routes detector output signals
(DET) to discriminator signals (DISC) on the J1 option
connector.
Coffee beans “M” Open When connected, this routes CTCSS/DTCS decode
signals (CDEC) to discriminator signals (DISC) on the
J1 option connector.
Coffee beans “N” Open When connected, this routes the external modulation
signals on D-SUB Pin 8 of J602 to the mic modulation
circuit. For newer F6061 radios, (not F5061) you
need to also cut Coffee Bean T as described in
Technical Update Bulletin, knowledgebase number
C7A9111737.
Coffee beans “Q” Close When cut, this isolates the CTS signal line on D-SUB
(pin 5 of J602) from the internal RS-232 interface
(pin 14 of IC91) (Note: for this modification, you
must connect coffee beans “P”)
Coffee beans “P” Open When connect this, it connects CTS signal line on DSUB
(pin 5 of J602) from RTS signal line on D-SUB
(pin 15 of J602) (Note: for this modification, you
must cut coffee beans “Q”)
Coffee beans “S” These coffee beans are the PTT inverted logic level.
Coffee bean “T” Closed This must be cut in newer F6061 radios after serial
numbers described in Technical Update Bulletin,
knowledgebase number C7A9111737
