Battery Adapter for PRC-25 & PRC-77 PRC-74, A, B, C & D Versions

Radio Description:
PRC-25 Man portable, nautical radio - one tube. Was the predecessor of the PRC-77.
PRC-77 is fully transistorized.

Specifications:
Original battery designation BA 4386/PRC25.
Original battery voltage output 14.4 VDC & 3 VDC.

Construction:
18 long "C" type cells in series/parallel.

Adapter Substitutions:
12 "C" cells.

Parts List:
12 - 1 "C". cell holder Radio Shack Part Number 270-402, 1 dead PRC-25/77 battery, hook-up wire, electrical & packing tape, 2 small flat head screws, cardboard cereal box, corrugated cardboard.

Special Notes:
Install adapter or original batteries carefully to radio set to avoid socket breakage. Feel your way when you plug it in.

Instructions:
Open flaps on the cardboard cover of a discharged BA-4386. Slide out guts. Using the packing tape, tape all edges of the battery cover so to reinforce them. This will make it last longer. Set the cover aside for now.

On one end of the "guts", you'll find the connector & end spacer (both usually white plastic). Use the flat head screws, and screw the connector to the block. Be sure the .D" center pin is facing the correct direction, see [Figure 1].

Cut a rectangle 8-1/8" x 3-1/8" from the cereal box. Take all 12 bakery holders, and using a file or sandpaper, rough-up the bottom & the sides of each, this will help the glue to stick. Glue the holders to the cardboard as shown in [Figure 1].

Remember one red wire (Positive) up and one red wire down. This will make the wiring much easier.

Solder and tape wires as shown in [Figure 2 & 3]. Don't forget to add the attention wire. To keep things neat, glue down the taped wires to the ends of the holder.

Set the socket/spacer block next to the holder, and solder the red, black and green (extension wire) as shown in [Figure 1].

Next, glue the spacer block to the end holders. Use a lot of glue from the glue gun for this joint.

Cut 12 - 16, 7/8" x 3-1/8" corrugated cardboard strips and glue together as shown in [Figure 1]. This will form the end spacer block.

Lastly, insert 12 fresh "C" cells, place the adapter back into it's cover, and install in the PRC-25 or PRC-77.

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