C-211-G Instruction Manual R. F. Amplifier
C-211-G
R.F. AMPLIFIER
The Mirage C-211-G is the next generation of Power Amplifiers for 222 - 225 MHz.
New features make it the most useful and versatile amplifier available. Features include
automatic power shut-down circuitry for protection against high antenna VSWR, high
temperature and excessive R.F. power input. A newly designed GaAsFET receive preamp provides high gain and low noise amplification for weak signal applications. The
pre-amp includes an attenuator to reduce signal output level. This is useful in preventing
Receiver Overload and subsequent Intermodulation Distortion caused by strong signals.
Provision is made for automatic or remote (external) keying, and for remote control of all
front panel functions using the Mirage RC-1 Remote Control Unit. The Mirage C-211-G
is capable of FM, SSB, and CW operational modes.
SPECIFICATIONS
Frequency Range...................................................................222 - 225 MHz
R.F. Input Power (Drive).......................................................250 mW to 5 Watts
R.F. Output Power................................................................. 110 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)
VSWR Power Shutdown Point ............................................. 3:1 Approximately
R.F. Input Power Shutdown Point.........................................5 Watts nominal
Temperature Power Shutdown Point..................................... 175 degrees F.
Keying...................................................................................Automatic (R.F. sensing) or
remote (external)
Input/Output Impedance........................................................ 50 Ohms
R.F. Connectors..................................................................... SO-239 (UHF)
Remote keying connector......................................................RCA phono
Remote control connector ..................................................... 6 pin Molex
Supply Voltage......................................................................13.8 VDC (for full R.F.
power output)
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C-211-G Instruction Manual R. F. Amplifier
Supply Current ...................................................................... 25 Amps (nominal)
Fuse ....................................................................................... Low voltage, fast blow.
35 Amps
Physical Dimensions.............................................................12 x 3 x 5-1/2 inches
Weight...................................................................................5 lbs.
INSTALLATION
The Mirage C-211-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 a minimum #8 gauge wire. 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 under the left side cover near the power supply leads, in the "up"
position. The switch may be accessed through the fourth slot from the rear using an
appropriate small tool. If desired, the transmit relay hold-in (hang-time) may be adjusted
by adjusting the potentiometer located behind the twelfth slot from the rear on the right
side of the amplifier. If external amplifier keying is desired, a switched ground
connection must be provided to the center pin of the RCA phono jack.
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.
TX LED.....................................................................Indicates that the amplifier is
keyed on.
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C-211-G Instruction Manual R. F. Amplifier
SWR/OVERLOAD LED .......................................... Indicates amplifier shutdown
due to excessive VSWR,
temperature, or R.F. drive
power.
REAR PANEL CONNECTORS
RADIO (SO-239)......................................................R.F. input from radio.
ANT (SO-239)...........................................................R.F. output to antenna.
RCA phono (Unmarked)...........................................Remote keying.
Molex (Unmarked).................................................... Remote control.
INTERNAL ADJUSTMENTS
SSB DELAY.............................................................This allows you to change the
holding time on the XMT
relay. This adjustment is
accessible through the 11th or
12th slot from the back on the
right side.
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.
TROUBLESHOOTING
The Mirage C-211-G is designed for long, trouble-free performance and should not
require extensive troubleshooting in the field. Many causes of common malfunctions are
eliminated by the built-in protective circuitry. NOTE: In the event of automatic power
shut-down, the amplifier must be turned off, and the cause of shut-down determined
and removed. In case of difficulty check the following before assuming amplifier
malfunction:
a. Loose antenna or power supply connections.
b. VSWR of antenna system.
c. Coaxial cables from radio to amplifier, and amplifier to antenna.
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C-211-G Instruction Manual R. F. Amplifier
d. Output voltage of power supply.
e. Power output of radio.
f. Improper fuse rating.
WARNING:
This unit should not be op erated w ith the cover removed Th e cover
confines R.F. radiation, including harmonics, to the inside of the
case. Operation of the unit wi thout the cover could resu lt in direct
harmonic radiation. The harmonic filters contained in the circu it
will not suppress direct radiation.
IMPORTANT REMINDER
All MIRAGE amplifiers manufactured for amateur radio - with the exception of
repeater amplifiers - are rated as ICAS - Intermittent Commercial and Amateur
Service. This generally means 5 minute duty cycles, i.e. 5 minutes transmitting, 5
minutes receiving.
Although all of our units, except the hand helds, have thermal protection, continued
use where this cut out occurs can damage transistors.
TECHNICAL ASSISTANCE
If you have any problem with this unit first check the appropriate section of this manual.
If the manual does not reference your problem or your problem is not solved by reading
the manual you may call MIRAGE at 601-323-8287. You will be best helped if you have
your unit, manual and all information on your station handy so you can answer any
questions the technicians may ask.
You can also send questions by mail to MIRAGE, 921 HWY 25 South, Starkville, MS
39759 or by Fax to 601-323-6551. Send a complete description of your problem, an
explanation of exactly how you are using your unit, and a complete description of your
station.
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