Acom 1200S Installation, Operation And Maintenance Manual page 17

User's Manual | ACOM 1200S | 1.8-54 MHz Linear Power Amplifier
a) GND stud
First, connect the wing-nut grounding stud of the amplifier (on the rear panel, marked GND) to the station's
grounding system (see
Figure 2-2 Rear panel - Connections
Note that the grounding system may have to withstand currents over 15 A with
insignificant voltage drop on it. Therefore, it may be necessary to improve it
considerably, i.e., to become less resistive, with heavier leads and lower-resistive ground
path. The grounding leads should be at least 4 mm² (AWG 11 or SWG 13).
For details and recommendations on the grounding and RF counterpoise system concerning the
electromagnetic compatibility see also Section
.
problems
b) KEY-IN socket
This is the amplifier's input for receive/transmit control from the transceiver.
The transceiver controls the amplifier from receive mode into transmit mode (RX/TX) by grounding of the
KEY-IN input.
Run a shielded cable from the "ground on transmit" socket or terminal on your transceiver to the amplifier
rear panel KEY-IN socket (see
RCA phono plug.
The switching voltage presented from amplifier KEY-IN socket to the transceiver
"ground on transmit" output does not exceed 12 V (positive to the ground). The closed-
circuit current is below 6 mA (see Section
Your amplifier will not work if KEY-IN input is not connected properly.
Transceiver producers give different names to this output and they are for instance
TX-GND, SEND, T/R-LINE, PTT, etc. Some transceivers require that "ground on transmit"
is implemented via a software command, or by changing the setting of a switch on the
rear panel, or interior of the transceiver. Check your transceiver's manual.
c) KEY-OUT socket
This is the amplifier's transmit-enabling control output to the transceiver.
The KEY-OUT socket on the rear panel provides an extra control signal from the amplifier to the
transceiver. This can be used for improving the receive/transmit (RX/TX) switching safety.
August 2021
WARNING
3.6.f) Elimination of electromagnetic compatibility (EMC)
Figure 2-2 Rear panel - Connections
8.1.j) Receive / transmit control
, Pos. (a)).
, Pos. (b)). The KEY-IN socket uses a standard
S e c t i o n INSTALLATION | Page 17 of 60
).