Introduction
This manual covers the installation and operation of the MICOM RM125 and RM125R 125W HF-SSB
rack-mount/desktop continuous duty transceivers, part of the MICOM-3 line of HF-SSB radio sets. It
also presents the FLN3175 MICOM RM1200 1 kW linear high-power RF amplifier unit, which uses the
RM125 or RM125R as exciter for a complete 1 kW transceiver.
The manual covers only procedures specific to the MICOM RM125/RM125R and RM1200; the other
procedures, which are common to the whole MICOM-3 product line, are described in the “Owner’s
Guide, MICOM-3E/3T/3R HF-SSB Transceivers”, Publication 6886867J01, and in other MICOM-3
Supplements that cover optional features applicable to your radio set.
Description
General
Figure 1 shows a general view of a typical 125W transceiver (the RM125 version).
MICOM RM-125
USB
MICOM-3
1
?
@
/
P
R
S
7
*
Q
J
M
K
N
L
O
5
6
T
U
V
8
9
A
D
B
E
C
F
2
3
0
#
YW
ZX
MENU
Es c
P
GPS
ALARM
F1
F2
F3
F4
G
H
I
4
Figure 1. Typical RM125, General View
The RM125/RM125R radio set includes a standard MICOM-3 transceiver, with a 110/220 VAC,
50/60 Hz power supply contained in a compact chassis, suitable for installation in a 19” rack or
desktop.
Internal cooling fans enable operation over a wide range of temperatures, for continuous-duty data
transmission. The radio has multiple accessories connectors, for system interconnections.
The AC input voltage range is automatically switched between 110 and 220 VAC, and therefore the
equipment can be used in the United States of America as well as in other countries. As a backup,
RM125/RM125R can also use 13.8 V DC power from an external lead-gel or lead-acid battery, which
is automatically charged by the internal AC power supply. When an external battery is connected, the
RM125/RM125R can continue operating on battery power during AC mains failure or in case the AC
power is switched off.
Note
An external 13.8 VDC DC power source, suitable for powering HF-SSB
transceivers, can also be used. The external source must be connected through a
series protection diode and a 30A fuse.
The RM125 and RM125R are well suited for base station applications, and can be directly connected
to a wide range of broadband or tuned antennas, including whip, dipole, traveling wave, delta, and
2
6888882V02
