SBE SB2-LA - Page 11

of the cover and lift straight up. A small soft-bristle brush and a vacuum
cleaner works best for this operation. Be sure that none of the components
is disturbed when cleaning.
The amplifier tubes are operated conservatively and, unless a heavy overload
is applied for an extended period, they should operate for several thousand
hours without deterioration. Should replacement be indicated by loss in out-
put or low plate current (usually both), it is recommended that a complete
new set be installed. ene <¢ pio
IMPORTANT
THE (6JE6) TUBES USEDIUIN THE SB2-LAVARE PACTORY BAL-
ANCED. WHEN REPLACING, BALANCED TUBES MAY BE OB-
TAINED THROUGH YOUR SBE DEALER OR.CHECK STOCK TUBES
FOR BALANCED MU.
It will be found that standby current will run rather high for the first hour or
so of operation and this will gradually fall to the correct level. If necessary,
the bias should be adjusted as required until the new tubes age a vit.
A slight blue glow within the tube does not necessarily indicate a defective iube.
However, if plate current is radically high or low, suspect a defective tube.
This is usually indicated by excessive blue glow, color on the plate or the tube
envelope abnormally cool.
a a EO:
to see that it is intact. The unit will transmit properly if the fuse is open, but ~
undue stress will be placed on the power supply components which will reduce
their life. F2 should not fail except under a prolonged B supply short circuit.
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