User's Manual

ALPHA 9500 Interim OPERATING MANUAL

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6.4 Normal Use

6.4.1 Tubes

The Alpha 9500 makes use of a single 8877 (3CX1500A7) ceramic triode tube manufactured by

CPI Eimac corporation.

6.4.2 Interlocks

The ALPHA 9500 is equipped with a cover interlock switch intended to remove primary power

from the ampliﬁer, and a crowbar to short-circuit the high voltage to chassis whenever the cover

is lifted. These interlocks are designed to protect against dangerous electric shock resulting from

accidental contact with the lethal voltages inside the ampliﬁer.

WARNING!

ALWAYS DISCONNECT THE AC LINE CORD FROM THE POWER SOURCE BEFORE

REMOVING THE TOP COVER FROM THE 9500 FOR ANY REASON!

Cover interlocks are intended only as back-up protection against accidents. Never depend

on them! Always disconnect the power cord from the AC mains before removing the cover!

Interlock switches should not be disabled for any reason.

6.4.3 Fuses

Never replace any fuse with one of a different type or greater current rating. Blowing of one

or both primary line fuses indicates that the maximum safe average power capability of the

ampliﬁer has been substantially exceeded or that an equipment failure has occurred. USE ONLY

20 AMP, 250 VOLT RATED FUSES for 190-220 VAC service. 25 amp fuses may be used with caution

for line voltages of 90-130V.

The slow-blow fuse F3, located below the primary line fuses, may prevent damage to the step-

start resistors and HV rectiﬁers in the event of abnormal turn-on conditions or HV faults. If the AC

interlock is defeated and primary power is applied while the HV crowbar is closed, the step-start

fuses will normally blow.