Acom 1500 User Manual page 17

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
Run a shielded cable from the "ground on transmit" socket or terminal on your transceiver to the amplifier
KEY-IN socket (see
Figure 2-1 Rear panel - Connections
phono plug.
The switching voltage presented from amplifier KEY-IN socket to the transceiver
"ground on transmit" output does not exceed 14 V (positive to the ground). The closed-
circuit current is below 8 mA.
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.
e) KEY-OUT socket
This is the amplifier's transmit-enabling control output to the transceiver.
The KEY-OUT socket (see
the amplifier to the transceiver. It could be used to improve the transmit/receive (RX/TX) switching safety.
KEY-OUT is a low-power open-drain output, make sure that the signal voltage coming
from the respective transceiver connection does not exceed 50 VDC (open circuit) and
the closed-circuit current is below 20 mA.
If your transceiver has a suitable input that disables transmission unless grounded externally, we
recommend that you connect it with a shielded cable terminated in a Phono (RCA) connector to the
KEY-OUT socket of the amplifier.
ACOM 1500 will operate normally with KEY-OUT unconnected if your transceiver has no
such input.
Transceiver producers give different names to this input and they are for instance
TX-INHIBIT, MUTE, LINEAR, etc. Check your transceiver's manual.
August 2021
Figure 2-1 Rear panel - Connections
NOTICE
, Pos. (d)). The KEY-IN socket uses a standard RCA
, Pos. (e)) provides an extra control signal from
S e c t i o n INSTALLATION | Page 17 of 52