Pride Amp Series, Service Manual

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Copyright © 2004 CBTricks.com
Pride DX300 CHAPTER 4
Maintenance
The following information is presented so that the competent service technician should have no trouble in
performing routine service on the Pride DX-300.
Lethally high voltages are present inside the amplifier unit. Never remove either top or bottom cover when power
line is connected.
DO NOT attempt to operate unit when covers are removed:
1)
Lethal voltages would be open to contact.
2) Protective interlock on top cover will short circuit the high voltage power supply; attempting to operate under
these conditions can cause damage to power supply, amplifier tube, or both.
3)
Attempting to operate the unit with bottom cover removed causes loss of air pressure to the tube, and can
cause rapid failure of the tube.
4)
Attempting to operate the unit with top cover removed (with the interlock blocked) may make the amplifier
erratic in tuning and performance due to the high level of R.F. on the top chassis coupling to the coaxial input
cable at the rear of the chassis. If repairs should be necessary, contact the factory, or a repair facility with proper
equipment and technical experience for the servicing of high power amplifiers.
If covers need be removed, allow two minutes after turning the unit off and unplugging the line cord before
removing covers.
4.0 Plate current measurement:
Plate current can be monitored by means of an external meter plugged into the METERING jack on the back
panel. The voltmeter should be connected as below:
Figure 4-0 Meter Connection
The following chart converts voltage as read at the metering jack to actual plate current.
.17V = 50mA 1.02V = 300mA
.34V = 100mA 1.19V = 350mA
.51V = 150mA 1.36V = 400mA
.68V = 200mA 1.53V = 450mA
.85V = 250mA 1.70V = 500mA