Kenwood TS-790A Instruction Manual page 25

EXT CONT pin assignments
Pin |
number Symbol Use
1 43TXG Grounded during transmission in
430 MHz band. Normally at high
impedance. (Maximum permissi- |
ble voltage 20 V, maximum per- '
missible current 10 mA). :
External push to talk terminal
! transmission starts when
grounded.
, External ALC input @). ALC
; threshold is about —6 V.
Grounded during transmission in
1200 MHz band. Normaily at high
impedance. (Maximum permissi-
ble voltage 20 V, maximum per-
missible current 10 mA).
{Optional in the TS-790A/790E).
External ALC input @. ALC
threshold is about —6 V. |
Grounded during transmission in '
144 MHz band. Normally at high
impedance. (Maximum permissi-
bla valtage 20 V, maximum per-
| missible current 10 mA}.
' External ALC input (3). ALC
threshold is about -6 V.
w! > Tz a
Reference information
* Circuit of aach TXG (pin numbers 1,4, and 6).
TXG
Output cannot be used to drive reiay
directly.
* Circuit of ALC
—>}|— ALC input @ (pin 3)
>} ALC input (3) (pin 7}
KEY jack
Using shielded line, connect a 1/8" phone plug to this
jack for CW operation. Open-terminal voltage is ap-
proximately 5.5 VDC.
4-1-3. Microphone
@ @ UP/DWN (Up/Down) switches
These switches are used to step the VFO frequency
or memory channel up and down. The frequency will
change continuously if the switches are pressed and
held.
@) PTT (Push To Talk) switch
The transceiver will be placed into Transmit whenever
this switch is pressed. Scan will be cleared when this
switch is pressed.
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