HARBACH ELECTRONICS PM-200, Installation Instructions

PM-200 POWER SUPPLY MODULE INSTALLATION INSTRUCTIONS 

PARTS SUPPLIED WITH THIS KIT: 

 
(1) PM-200 Power Supply Module Circuit Board 

(1) 3.6k

Ω

 ¼-Watt Resistor 

(8) 

1N5408 

Diodes 

     (1) 

1

Ω

 3-Watt Resistor 

(14) 1M

Ω

¼-Watt 

Resistors 

    (12) 

82k

Ω

 3-Watt Resistors 

(6) 180

μ

F 450VDC Electrolytic Capacitors   

(1) 910

Ω

 2-Watt Resistor 

(1) 15K

Ω

 ½-Watt Resistor   

(1) #20 5" Small Blue Wire 

 
 
To start the installation, read these instructions very carefully.  Unplug the amplifier and remove any 
input, output and control cables that may be connected to the back of the amplifier.  Remove the 
chassis from the case and remove the perforated sheet metal RF shield from the top of the chassis.  
Remove the tubes and place them in a safe place.  You are now ready to proceed with the 
installation. 
 
( ) 

Assemble the PM-200 Power Module according to the parts layout diagram.  Make sure 
resistors R1A-R6B are mounted approximately ¼” above the PC board.  All other components 
are mounted flush to the PC board.  In addition, solder one end of the 5” #20 

BLUE

 wire to the 

underside of the PC board at pad 

“V”

. 

 
( ) 

Place the amplifier on its side (transformer down).  Unsolder all wires connected to the power 
supply circuit board.  These are the 

RED

 and 

RED & YELLOW

 transformer wires on the top 

side of the circuit board, a 

GRAY

 wire and a 

YELLOW

 wire from the top side of the board 

(these wires pass through the hole in the circuit board), the 

(3) 4.7M

Ω

  resistor assembly

 on 

the bottom of the circuit board and the heavy 

BLUE

 HV wire on the bottom side of the board. 

( ) 

Remove the fixed end of the (3) 4.7M

Ω

 resistor assembly from the terminal strip lug and 

discard these resistors

. 

 
( )

Remove the (9) #6-32x3/8” screws, washers and nuts that secure the circuit board in place.  
Save this hardware. 

 
( ) 

Place the amplifier right side up and remove the 5 control knobs from their shafts. 

 
( ) 

Remove the 3 nuts and washers that secure the bandswitch, meter switch and sensitivity 
potentiometer and save them. 

 
( ) 

Remove the (4) #6-32x3/8” Phillips-head screws, washers and nuts that secure the front 
panel.  Save this hardware. 

( ) 

Gently tilt the front panel forward.  You may have to carefully pry it loose with a small 
screwdriver because the paint from the front panel may stick to the chassis.  Place the front 
panel down in front of the chassis. 

 
( ) 

Lift the circuit board from the front so that it tilts upward about 1”. 

 
( ) 

Using diagonal cutters, cut the old circuit board from the front left corner all the way back to 
the wire hole.  This will break out a path for the wires to exit.  Be careful not to cut any wires 
during this process.  This will free the old circuit board so that is can be removed without 
further unsoldering of wires. 

1