RM1200 1 kW Power Amplifier Option
1 kW System Description
The RM1200 1 kW power amplifier option, FLN3175, which uses the RM125/RM125R as an exciter,
expands the MICOM-3 product line by offering higher transmit power (up to 1 kW, PEP and average),
and thus longer reach and improved communications under bad propagation conditions and/or
strong interference. RM1200 consists of two units intended for rack mounting, together with the
RM125/RM125R: 1 kW RF linear power amplifier and AC-powered PS unit. The equipment is 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 semi-delta antennas.
Upon power-up, the RM1200 uses a low-level RF pilot signal from the exciter to automatically detect
the incoming frequency and select the optimum harmonic filter band in accordance with the
operating frequency. The frequency detection and filter switching is quite rapid, a capability needed
for ALE and adaptive communication modes.
The equipment is optimized for operation in conjunction with the RM125/RM125R radio set as
exciter and controller, using a dedicated communication interface and a flexible handshaking
protocol (to use these capabilities, order the special interface cable kit, option G156, for connecting
the 1 kW amplifier to the RM125/RM125R). The RM125/RM125R controls the 1 kW amplifier
operation, enables the operator to select the nominal transmit power, and the 1 kW amplifier
provides ALC feedback to adjust the RM125/RM125R drive power to the optimum level.
Although optimized for operation with the RM125/RM125R, RM1200 can be used with any HF-SSB
driver capable of providing the required drive power (approx. 40W), and appropriate interfacing.
Contact the manufacturer for details on the RM1200 interfacing requirements.
Protection circuits monitor the various operating conditions, and prevent damage to the 1 kW
amplifier by taking appropriate action, in accordance with the detected problem.
The 1 kW amplifier has several status indicators, and a front-panel LCD that enables the operator to
monitor the RM1200 operation. This LCD can be used to read the actual forward and reflected
power (or VSWR), and report problems such as the activation of protection circuits or technical
malfunctions. The LCD and the status indicators indicate the type of problem that has been detected,
thus helping the operator correct it.
In addition, the 1 kW amplifier has a serial RS-232 asynchronous interface that can be used for
maintenance and calibration: the program needed to use this interface is stored in the 1 kW
amplifier, and therefore any data communication terminal (or PC emulation program, for example,
the HyperTerminal utility available on PCs running under Microsoft Inc. Windows®) can be used.
The 1 kW amplifier is active only in the transmit mode: when not powered, in the receive mode, and
also after the protection circuits are activated, the 1 kW amplifier switches to the bypass mode, and
directly connects the radio set to the antenna system.
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