Kenwood TKR-740 Service Manual page 23

Notes:
*1 Remove R117.
*2 Remove R118.
Note: RAI and RAO (de-emphasized squelch controlled
audio) should be used for the receive audio in/out for an
encryption or scrambler board.
*3 Remove R120
Note: When DETI and DETO are used, (bypasses de-
emphasized squelch controlled audio) the TKR-740 can
not decode QT/DQT because the scrambler board will
not pass sub-audible tones. If the scrambler board
modification is need due to use of RAI and RAO, refer to
Its manufacturer' s Installation manual.
*4 If ANI side tone is to be output from an external speaker,
connect the ANI board side tone output line to terminal
RAI. If side tone output is to output from the front panel
local speaker, connect the board side tone output line to
IC45, pin 2 (IC45 device: LA4422).
4. FPU Setting For Optional Board
Voice scrambler
1) Select each item to enable for scrambler unit.
<model>➔<TKR-740>➔<158-174>➔<Voice Scrambler>
➔"OK"
2) Select the channel(s) which will use scramble mode and
then press [ F10].
Select a voice scrambler code address (1-of-16, 4 bit BCD)
if necessary.
3) Assign the "Scrambler On/Off" function to front panel
any PF key or AUX Input.
<Edit>➔<Key Assignment>➔[PF 2]➔"Scrambler On/
Off"
<Edit>➔<Optional features>➔<AUX I/O ports...>➔
<AUX Input Functions(12-pin & 25-pin...>➔<AUX In>
APPLICATION NOTE
*5 Remove R115.
*6 When using an EXT PTT, connect the PTT wires of option
*7 When using a Remote PTT, connect PTT wires of option
*8 An external switch may be connected to an AUX I (I/O) if
*9 Some ANI boards have a "channel busy" input line. Use
*10 Some ANI boards have a "speaker mute" output line.
The scrambler function is primarily designed for TKR-740
base station operation. However if used in repeater operation,
be aware that the repeated audio operation differ between
the RAI/RAO and DETI/DETO terminals. When RAI/RAO are
used, de-scrambled (clear) audio will be heard from the local
speaker and scrambled audio will be transmitted over the air;
RAI/RAO are the preferred scrambler receiver audio connection
terminals. When DETI/DETO are used, de-scrambled (clear)
audio will be heard from both the local speaker and transmitted
over the air. Since the repeated audio should leave the repeater
scrambled (in most applications), it is recommended to use
the RAI and RAO.
board to TESTI/TESTO terminal.
Remove R116.
board to RPTTI/RPTTO terminal..
Remove R114.
an emergency function is required.
an AUX (I/O) programmed as Carrier Operated Relay or
Tone Operated Relay (COR or TOR) output may be used
(alternative: use the Squelch Control (SC) line on the 25
Pin D-sub).
Use the SPM line on the 25 Pin D-sub.
TKR-740
23