User's Manual

6888882V04

RCK1000 Owners-Guide-v4.doc

1KW Amplifier

The 1KW amplifier consists of the following main functions:

 Linear RF power amplifier covering the HF band. The RF amplifier consists of 4

independent amplification modules, whose outputs are combined to obtain the required

RF output power. The RF drive signal, applied to the RF IN connector, is amplified to the

appropriate level, as selected on the RM125/RM125R.

 Harmonic filter. This is a low-pass filter whose purpose is to attenuate harmonics and

other undesired signals at frequencies above the actual operating frequency, before the

amplified output signal is applied to the RF OUT connector. The filter has 8 sub-bands:

the filter that fits the operating frequency is automatically inserted in the transmit path.

The required frequency information is received from the RM125/RM125R; in addition, the

1KW amplifier measures the actual frequency of the RF drive signal as part of its tuning

process (if the frequency cannot be measured, the highest band is selected).

 Bypass circuits. These circuits automatically bypass the 1KW amplifier and establish a

direct path between the RF IN and RF OUT connectors when power is not available, or a

critical malfunction is detected.

 Control circuits. These circuits control 1KW amplifier operation, interface with the

exciter/controller unit (RM125/RM125R), and take action to protect the amplifier when

necessary.

 Cooling subsystem, includes internal fans that enable operation over a wide range of

temperatures.

 Overdrive Protection

The input power is automatically adjusted by an automatic level control to achieve

optimal operating conditions for the amplifier. However, if the input drive power exceeds

about 80W the protection circuits prevent damage to the 1KW amplifier by bypassing it.

 High VSWR Protection

To obtain maximum forward power, the amplifier should be connected to a low VSWR

antenna system. In case of excessive VSWR, for example, because of mismatch or damage

to antenna system and/or feed cables, the ALC circuits prevent damage by reducing the

transmit power to safe values.

However, in case of excessive mismatch (for example, short or open circuit), the protection

circuits switch the 1KW amplifier to the bypass mode: in this case, the transceiver is

directly connected to the antenna.

 Overheating Protection

Special circuits protect the 1KW amplifier against overheating. If the temperature is too

high to enable full-power operation, the output power is automatically halved, until the

temperature returns to normal. However, if the temperature exceeds the maximum

allowed limit and damage may be caused, the protection circuits are activated and

bypass the amplifier.