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Kenwood TK-840 / TK840 information

Kenwood TK-840

TX: 425-500
RX: 435-495

Software only programs 450-488mhz. To override...
Hex dump programming file. 
At offset 116: 01 E0 AE 00 B2  (ch 01, tx E0 AE, rx 00 B2)
To get the bytes to edit into the file, use this formula:
(freq + 109.6)/.0125  then convert to hex and reverse the bytes (e.g. B200 to 00 B2)


Front panel controls:
PWR, VOL-UP, VOL-DOWN, SYS-DOWN, SYS-UP, GRP-DOWN, GRP-UP, SCAN, AUX

PWR + SYS-UP = "PROGRAM" THEN PRESS AUX = "89EC" THEN PRESS SCAN = "PROGRAM_"
PWR + SYS-UP = "PROGRAM" THEN PRESS SCAN = "PROGRAM_"
PWR + GRP-DOWN = "UHF F1" "TUNING" "7-1"
 PRESS SYS-UP/SYS-DOWN TO SELECT SYSTEM #
 PRESS GRP-UP/GRP-DOWN TO SELECT GROUP #
   THEN PRESS SCAN TO TOGGLE PROGRAM MODE:
    SYS-UP/SYS-DOWN TO SELECT PROGRAMMING OPTION (SQL,BAL,FQT,FDQT,FID,SENS,POWR,DEV)
    GRP-UP/GRP-DOWN TO SELECT SETTING, AUX TO SCROLL THROUGH OPTIONS, SCAN TO EXIT


PWR + GRP-UP = DISPLAY TEST THEN SHOWS SYSTEM/GROUP #
   PRESS SCAN TO TOGGLE SPEAKER MUTE/UNMUTE
   PRESS AUX TO TOGGLE TALKAROUND
   PRESS SYS UP/DOWN & GRP UP/DOWN TO SELECT SYSTEM/GROUP

S G (G 1 THRU 8 ALL THE SAME)
1-1 467.500
2-1 467.075
3-1 468.850
4-1 469.075
5-1 469.500  RX 470.500
6-1 487.400  RX 487.500
7-1 487.900 RX 487.875

START RADIO NORMALLY IF PROGRAMMING WITH PC & RIB


Here is a description of how the PC/radio talk over the serial interface:

PC INTERFACE IS 1200 8N1
PC: TOGGLES CTS
PC: "PROGRAM"
RADIO: "<06><01>"
PC: (ONE OR TWO-BYTE PASSWORD)
RADIO: "" IF PASSWORD IS INVALID
PC: TOGGLES CTS OR DOES SOMETHING ELSE TO RESET RADIO AFTER 3 INVALID PASSWORDS

RADIO REPLIES WITH MODEL #
PC SENDS PASSWORD (0-10 UPPERCASE CHARACTERS AND/OR PUNCTUATION).

Raise RTS, send 11 bytes, drop RTS
A = 04 41 FF FF FF FF FF FF FF FF FF 

04 THEN PASSWORD PADDED WITH FF'S.

Get reply from radio. 15 = bad password.

chars decimal 32 thru 96