Marti Electronics SRPT-30 User Manual page 30

The external supply or battery must be capable of delivering 8/10 Amps if running the SRPT-30/40A at maximum
output power. Connect up the unit using the Marti 585-141 12-15 VDC External Supply Cable. If choose to build your
own cable then follow the drawing on Figure 2A: Connect three positive leads of the supply to pins 6, 7, and 14 of a 15-
pin female D connector. Connect three negative leads of the supply to three ground pins (pins 1, 11, and 12) of the 15-
pin female D connector. Each of the three positive leads and each of the three negative leads should be an 18 gauge
wire. You may also use one 12 gauge wire for each positive and negative leads and split the stranded ends into three at
the connector end.
FOR 12-15 VOLT EXTERNAL SUPPLY, THE OPTIMUM VOLTAGE IS FROM 12 TO 15 VOLTS.
APPLYING A VOLTAGE LOWER THAN 12 VOLTS, WILL LIMIT THE MAXIMUM RF OUTPUT
ALSO, THE EXTERNAL BATTERY OR POWER SUPPLY SHOULD BE CAPABLE OF HANDLING A
CONSTANT 10 AMPS. THERE WILL BE A DROP IN VOLTAGE ACROSS THE POWER CABLES.
THE POWER CABLES SHOULD BE AS SHORT AS POSSIBLE AND AS HEAVY GAUGE AS
POSSIBLE. EXPECT A COUPLE OF VOLTS DROP WHEN OPERATING THROUGH A CIGARETTE
It is best to have an external switch between the external supply and the unit. Make sure the switch is in the open
position before connecting it to external supply. Otherwise make sure that when connecting the positive lead to the
external source that the 15-pin D connector is not connected to the SRPT-30/40A.
With the front panel AC LINE switch in the ON position, plug in the 15-pin D connector into the ACCESSORY
connector located in the rear of the SRPT-30/40A. Turn on external supply (if have a switch). With a voltmeter, measure
the voltage on the output of the external supply insuring that it is between 12 and 15 VDC. Switch the front panel AC
LINE switch to the OFF position. The unit should power up.
External DC Supply (15-30 Volt) Operation
Make sure that the SRPT-30/40A is not connected to an AC line. The front panel AC LINE switch does not control
the External DC Supply (15-30 Volt) operation. Therefore it does not matter what position it is in.
The external supply or battery must be capable of delivering 8/10 Amps if running the SRPT-30/40A at maximum
output power. Connect up the unit using the Marti 585-142 15-30 VDC External Supply Cable. If choose to build your
own cable then follow the drawing on Figure 2B: Connect three positive leads of the supply to three 15-30VDC pins
(pins 2, 3, and 10). Connect three negative leads of the supply to three ground pins (pins 1, 11, and 2). Each of the three
positive leads and each of the three negative leads should be an 18 gauge wire. You may also use one 12 gauge wire for
each positive and negative leads and split the stranded ends into three at the connector end.
It is best to have an external switch between the external supply and the unit. Make sure the switch is in the open
position before connecting it to external supply. Otherwise make sure that when connecting the positive lead to the
external source that the 15-pin D connector is not connected to the SRPT-30/40A.
Plug in the 15-pin D connector into the ACCESSORY connector located in the rear of the SRPT-30/40A. Turn on
external supply (if have a switch). With a voltmeter, measure the voltage on the output of the external supply insuring
that it is between 12 and 15 VDC. The unit should power up.
From 16 to 20 VDC, the SRPT-30/40A will transmit up to 50 Watts RF output. From 20 to 30 VDC the SRPT-40A
maximum output power will derate linearly down to 20 watts.
ATTENTION
POWER.
LIGHTER.
8/7/2003
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