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Series SPXXXVD, SPXXXVDA and SPXXXVDG preamplifiers have been designed for the most demanding commercial and military applications. Each model has been optimized for the lowest noise figure consistent with excellent strong signal handling capability. These preamplifiers are suitable for use in any receiver or converter/receiver system. Each preamplifier is housed in a rugged low profile custom aluminum enclosure finished with military grade black urethane enamel. Female BNC coaxial fittings are provided for the input and output connections. Other connectors or connector combinations are available. Complete rf shielding is maintained with a feedthrough capacitor for the dc power connection. Mounting holes, suitable for #4 hardware, are located at each corner of the bottom plate.
Several models of preamplifiers are available for most frequency ranges. Selection of the most suitable model for a particular application will depend primarily on the noise figure and overload characteristics required. Preamplifier models using dual-gate MOSFET and bipolar transistor devices (part numbers with suffix VD or VDA) are suitable for most fixed location and mobile applications. Gallium-arsenide FET (GaAsFET) preamplifiers (part numbers with the suffix VDG) provide the lowest noise figures and highest immunity to overload of any preamplifier types. These preamplifiers would be well suited for those systems where absolute best coverage is desired, or in areas where strong signal levels are normally a problem.
Extensive testing of these preamplifiers on existing communications systems indicate that a signal-to-noise improvement of 6 - 14 dB can be expected. For example, a 10 dB signal-to-noise improvement in a mobile receiver performance would give a 100-watt base station or repeater the same range as a 1000 watt unit! Each and every preamplifier is precision aligned on our noise figure measuring equipment and should provide long trouble free operation.
Inline preamplifiers use rf sensing to detect the presence of transmitter power and immediately switch the preamplifier out of line. The rf relays used in the preamplifier will handle up to 25 watts of rf power. In systems where power amplifiers are used, the inline preamplifiers may be installed between the transceiver or transverter and power amplifier. Connected in this manner, the preamplifier need only handle the transceiver power (25 watts or less).
All preamplifiers are designed to be powered by a 10 - 16 volt dc source with a current consumption of 100 mA. Low power consumption along with the small size make these preamplifiers ideal for installation within existing equipment or systems, or for remote mounting at the antenna. Mounting the preamplifier at the antenna will provide the best system noise figure.
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Model
SP138-144VDG
SP225-240VDG
SP240-270VDG
SP270-300VDG
SP300-330VDG
SP330-360VDG
SP360-390VDG
SP390-420VDG
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Freq.
Range
(MHz)
138-144
225-240
240-270
270-300
300-330
330-360
360-390
390-420
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N.F.
(dB)
0.5
1.0
1.0
1.0
1.0
1.0
1.0
1.0
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Gain
(dB)
24
20
20
20
19
19
19
19
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1 dB
Comp.
(dBm)
+12
+12
+12
+12
+12
+12
+12
+12
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1 dB
Bandwidth
(MHz)
8.0
20
30
30
30
30
30
30
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Device
Type
GaAsFET
GaAsFET
GaAsFET
GaAsFET
GaAsFET
GaAsFET
GaAsFET
GaAsFET
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Price
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
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Supply voltage: 10 - 16 Vdc
Supply current: tx - 10 mA, rx - 100 mA
Weight: 4.0 oz.
Through mode VSWR: 1.25 max
Through mode attenuation: 0.5 dB max
Minimum power to rf switch: 0.5 watt
Dimensions: outline drawing
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Prices shown for standard BNC connectors
Add $10 for N, SMA - other types available
For custom frequency ranges see
Special Frequency Ranges or contact factory
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