VPA2577 Vehicle Power Adapter Cable

Background

The PRC-25 and PRC-77 radios have a POWER connector on the front panel that can be used to externally power the radios.  When the jumper plug is disconnected from the radio it opens the circuit between the internal battery and the radio allowing external power to be applied.  More information on the POWER connector.

VPA-2577 Description

This Vehicle Power Adapter connects 10 to 15 VDC from an external source to the main power terminals on the POWER connector and also has a dropping resistor to supply the PRC-25 with a little less than 3 Volts for the LITE check or the filament of the final tube.  In addition there is a voltage divider to supply the A10 module with about 3 Volts of diode bias.  The external power is applied through a pair of Power Pole connectors in the standard ARES configuration.  No battery is needed in the radio when the VPA2577 is used for power.

The VPA2577 leaves the battery terminals in the POWER connector open so if a battery is in the radio is will not be connected.  This allows the radio to be powered by the VPA2577 while in a vehicle and then you can jerk and run then use the battery in the radio just by connecting the jumper plug.

The length of this cable is about 3 feet.

CLP-PP

The CLP-PP cable that has a Cigarette Lighter Plug on one end, with an LED, and a pair of Power Pole connectors on the other end.  Can be used to power the VPA2577.  The length is about 5 feet.

CLP-77

This cable only works for the PRC-77, not the PRC-25.  Uses the same Cigarette Lighter Plug with the LED and fuse as the CLP-PP above, but has the POWER connector for the PRC-77.

Probably works on the PRC-1077, PRC-1088 and PRC-1099 since they use the same POWER connector for DC input, but not tested.

The mil connector is new and the unused contacts have not been soldered so you could use this cable as the starting point for adding other features found on the POWER connector.
More information on the POWER connector.

POWER Connector Kit

The Power Connector Kit  (PCK) includes a new 14 pin connector and cable clamp, a couple of inches of clear shrink tube to add a label to your cable and an instruction sheet that includes an enlarged image of the solder cup locations since the labels on the connector can be misleading.

This is also the connector used on the POWER connector on radios that are patterned after the PRC-25 and PRC-77 like the PRC-1099, etc.

This connector also can be used on both ends of a cable to make a CX-13291 SINCGARS Power Amplifier cable that connects the radio mount (J11 or J5) to the PA Mount J3.
More information on the POWER connector.

The VPA2577 will plug directly into the 257477BA-PP Battery Adapter and can power a PRC-25 or PRC-77 through the POWER connector.  This is a handy way to bench power a radio that does not require taking off the battery box.