Heathkit Model IP-17

Regulated Power Supply

Calibration Procedure

· With the power supply off, both meter pointers should be over the zero indication on each meter face.  If they are not, turn the mechanical zero-adjust screws at the bottom of each meter until the pointers are properly aligned.

Ancillary Equipment Needed

VTVM (optional)

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NOTES

· Remove all jumper wires between the chassis ground and common ground terminals.

· Remove all loads from the supply terminals.

· All circuit board mounted control adjustments are made from the top of the board, front to rear (see Figure 1).

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ZERO SET & 400V SET ADJUSTMENTS

(    )         Set the POWER switch to the OFF position.

(    )         Set the B+ OUTPUT control maximum counter-clockwise.

(    )         Set the C- OUTPUT control maximum counter-clockwise.

(    )         Set the VOLTMETER switch to the B+ VOLTS position.

(    )         Set the POWER switch to the STANDBY position. Allow the tubes to come up to operating temperature.

(    )         Set the ZERO VOLTAGE ADJUST control [second from left on circuit board] maximum counter-clockwise.

(    )         Set the 400 VOLT ADJUST control [first from left on circuit board] maximum clockwise.

(    )         Set the POWER switch to the ON position.

· There should be 0 output indicated on the current meter.

Meter Calibration without a VTVM

(    )*       Set the high voltage B+ OUTPUT control maximum counter-clockwise.

(    )*       Adjust the ZERO VOLTAGE ADJUST control until the voltage meter reads 0 V.

(    )*       Set the high voltage B+ OUTPUT control maximum clockwise.

(    )*       Adjust the 400 VOLT SET control clockwise until voltage meter reads 400 V.

· Because the ZERO SET and the 400 VOLT SET controls interact with each other, it will be necessary to repeat the above four steps* until no meter changes are observed.

(    )         Set the high voltage B+ OUTPUT control maximum counter-clockwise.

Meter Calibration using a VTVM

(    )         Set the high voltage B+ OUTPUT control maximum counter-clockwise.

(    )         Set the POWER switch to the STANDBY position.

(    )         Set the VTVM on a voltage scale capable of reading 400 VDC.

(    )         Connect the VTVM to the B+ output terminals.

(    )         Set the POWER switch to the ON position.

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(    )*       Set the high voltage B+ OUTPUT control maximum counter-clockwise.

(    )*       Adjust the ZERO VOLTAGE ADJUST control until the panel meter voltage reads 0 V.

(    )*       Adjust the high voltage B+ OUTPUT control until the VTVM reads 400 VDC.

(    )*       Adjust the 400 VOLT SET control clockwise until the panel voltage meter reads 400 V.

· Because the ZERO SET and the 400 VOLT SET controls interact with each other, it will be necessary to repeat the above four steps* until no meter changes are observed.

(    )         Set the high voltage B+ OUTPUT control maximum counter-clockwise.

(    )         Set the POWER switch to the STANDBY position.

(    )         Disconnect the VTVM from the B+ terminals.

(    )         Set the POWER switch to the ON position.

NEGATIVE BIAS VOLTAGE VERIFICATION

(    )         Set the C- OUTPUT control maximum counter-clockwise.

(    )         Set the VOLTMETER switch to the C- VOLTS position.

(    )         Set the C- OUTPUT control maximum counter-clockwise, meter should read 0 V.

(    )         Set the C- OUTPUT control maximum clockwise, meter should read over -100 V.

(    )         Set the C- OUTPUT control maximum counter-clockwise.

(    )         Set the POWER switch to the OFF position.

(    )         Set the VOLTMETER switch to the B+ VOLTS position.

(    )         Calibration procedure is completed.