Mirage C-22-G Instruction Manual

C-22-G Instruction Manual R. F. Amplifier

C-22-G

R.F. AMPLIFIER

The Mirage C-22-G is the next generation of Power Amplifiers for 220 - 225 MHz. New
features make it the most useful and versatile amplifier available. Features include
automatic power shut-down circuitry for protection against excessive R.F. power input.
A newly designed GaAsFET receive pre-amp provides high gain and low noise
amplification for weak signal applications. The pre-amp incl udes a selectable attenuator
to reduce signal output level. This is useful in preventing Receiver Overload and
subsequent Intermodulation Distortion caused by strong signals. The Mirage C-22-G is
capable of FM, SSB, and CW operational modes.

SPECIFICATIONS

Frequency Range.......................................................220 - 225 MHz

R.F. Input Power (Drive)...........................................0.4 - 4 Watts (5 Watts max.)

R.F. Output Power..................................................... 20 Watts with 2 Watts drive

Duty Cycle.................................................................Intermittent (ICAS)

Modes........................................................................ FM, SSB, CW

Receive Pre-amp ....................................................... GaAsFET, Gain 21/15 dB-Nominal.

Noise figures less than 0.6 dB. 1 dB
compression point greater than -13

dBm input (Nominal)

R.F. Input Power Shutdown Point............................. In excess of 5 Watts nominal

Keying.......................................................................Automatic (R.F. sensing)

Input/Output Impedance............................................ 50 Ohms

R.F. Connectors......................................................... SO-239 (UHF)

Supply Voltage.......................................................... 13.8 VDC (for full R.F. power

output)

Supply Current .......................................................... 4 Amps (nominal)

Fuse ...........................................................................Low voltage, fast blow. 7-1/2 Amps

Physical Dimensions.................................................3-1/2 x 2 x 7 inches

Weight.......................................................................1 1/4 pounds

INSTALLATION

The Mirage C-22-G may be mounted using the brackets supplied or simply placed in a
convenient operating position. In either case, there must be adequate ventilation for the
finned heat-sink. This generally means at least 1 inch clearance from the sink to any
surrounding enclosure and an unobstructed flow from the front to the back of the sink.
CAUTION: With extended use the heat sink becomes very hot. If it is necessary to
extend the D.C. power leads, use wire of the same gauge in order to avoid a voltage drop

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C-22-G Instruction Manual R. F. Amplifier

on your power leads. Use a minimum length of good quality 50 Ohm cable between the
radio and the amplifier. The antenna system should have a VSWR of 1.5:1 or better for
best performance. The receiving pre-amp gain is set to the high value at the factory. To
switch to minimum gain move the DIP switch, which is located behind the left side cover
where there is a 1/4" hole, to the "up" position. If desired, the transmit relay hold-in
(hang-time) may be adjusted by adjusting the potentiometer located behind the hole on
the right side of the amplifier.

FRONT PANEL SWITCHES/LED'S

POWER ON/OFF SWITCH .........................Turns the D.C. power ON or OFF.

SSB/FM SWITCH.........................................Selects relay time delay for the mode

of operation. The relay drop time is

lengthened for the SSB mode of

operation.

PRE-AMP ON/OFF SWITCH...................... Turns Pre-amp power ON or OFF.

POWER LED................................................Indicates that D.C. power is applied.

PRE-AMP LED............................................. Indicates that the pre-amp is turned

ON.

OVERLOAD LED........................................ Indicates amplifier shutdown due to

excessive R.F. drive power. Reset

by turning OFF then ON.

REAR PANEL CONNECTORS

RADIO (SO-239).......................................... R.F. input from radio.

ANT (SO-239)...............................................R.F. output to antenna.

INTERNAL ADJUSTMENTS

SSB DELAY................................................. This allows the R.F. relay "hang-

time" or delay to be adjusted to the

time desired.

PRE-AMP ATTENUATOR SWITCH .........Sets the pre-amp gain to full or

reduced value.

INPUT VSWR AND OUTPUT POWER..... These adjustments are made at the

factory and should not require field

adjustment.

PRE-AMP TUNING..................................... These adjustments are also made at

the factory for best gain and noise

figure performance. They should not

require field adjustment.

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