IC-PS35, IC-PS30 & IC-765 PSU Adjustment

by Adam M. Farson, VA7OJ/AB4OJ

General:

The IC-PS35 "bathtub" modular switching power supply is an accessory for the IC-751 and IC-751A. Variants of the IC-PS35 are used in the IC-PS30 system power supply, and also in the IC-761 and IC-765. The voltage and current-protector adjustments are identical for all three versions, with the exception of a difference in the adjustment-point designations.

Required Test Equipment:

Table 1: Adjustment points and parameters. (Refer to Figures below.)
ADJUSTMENT ADJUSTMENT CONDITIONS MEASUREMENTS VALUE ADJUSTMENT POINT
UNIT LOCATION UNIT ADJUST
OUTPUT VOLTAGE 1
  • Rheostat: 1.38Ω
  • AC power switch: ON
 IC-765 REG,  IC-PS35
(Fig.2)		 Connect a DC voltmeter
as shown in Figure 1.		 13.8V IC-765 REG,
IC-PS35		 R14
IC-PS30 REG
(Fig. 3) 		 IC-PS30
REG		 R5
CURRENT PROTECTOR
OPERATION		 2
  • Rheostat: 0.55Ω
  • AC power switch: ON
 IC-765 REG, IC-PS35
(Fig. 2)		 Adjust pot. until output
 voltage just drops.		 IC-765 REG,
IC-PS35		 R19
IC-PS30 REG
(Fig. 3)		 IC-PS30
REG		 R10
IC-PS30 VOLTAGE
SCALE		 3
  • Rheostat: 1.38Ω
  • AC power switch: ON
  • Meter switch: Vo
 IC-PS30
METER
SWITCH
(Fig. 4)		 Connect a DC voltmeter
as shown in Figure 1.		 IC-PS35 meter: 13.8V IC-PS30
METER
SWITCH		 R4
IC-PS30 CURRENT
ZERO 		4
  • No load
  • AC power switch: ON
  • Meter switch: Io
 IC-PS30
METER CAL
(Fig. 5)		 Observe IC-PS30
meter.		 IC-PS30 meter: 0A IC-PS30
METER
CAL		 R15
IC-PS30 CURRENT
SCALE 		5
  • Rheostat: 0.69Ω
  • AC power switch: ON
  • Meter switch: Io
 IC-PS30
METER CAL
(Fig. 5)		 Connect a DC ammeter
as shown in Figure 1.		 IC-PS30 meter: 20A IC-PS30
METER
CAL		 R14

 

Fig. 1: Test equipment connections.
Fig. 1: Test equipment connections. Image courtesy Icom Inc.

 

Fig.2: Adjustment points (IC-765 REG board & IC-PS35).
Fig.2: Adjustment points (REG board & IC-PS35). Image courtesy Icom Inc. 
 
Fig.3: Adjustment points (IC-PS30 REG board).
Fig. 3: Adjustment points (IC-PS30 REG board). Photo courtesy K5JN. 
 
Fig. 4: IC-PS30 meter switch, showing R4 (left).
Fig. 4: IC-PS meter switch, showing R4 (left). Photo courtesy K5JN.

 

Fig. 5: IC-PS30 meter calibration board, showing R14 and R15.
Fig. 5: IC-PS 30 meter calibration board, showing R14 and R15. Photo courtesy K5JN.
 

Table 2: IC-PS30 Connectors
Description Icom Part No.
Chassis connector 6510003760
Pins for connector 6510003790
Cable connector 6510013170
Pins for cable 6510007650 
Copyright © 2005 A. Farson VA7OJ/AB4OJ. All rights reserved.
Based on e-mail discussions with Ralph Marrs K5JN and Walt Szachara W2OKF.
Last updated: 06/15/2018.