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DOCNUMBER 8410
Document Issue 1.1
August 2015
Page 4–3
RKR Designs LLC
Alpha 8410 Linear Amplifier User Manual
Setting Up the Amplifier
CAUTION
!
CAUTION!
Do not use the transformer’s shipping bolts. They are too
long and will damage the transformer!
4.3 Check the Tubes and Exhaust Chimney
With the amplifier cover removed, check and, if necessary, adjust the
tubes and the exhaust chimney.
Procedure 4-3
Check the tubes and the exhaust chimney
Step 1
Ensure that the tubes are firmly seated in their sockets.
The 4CX1500B tubes have bayonet-style bases. Each tube is installed
onto a central pin in the tube socket and then rotated clockwise into place
so that the flanges on the tube line up with the connectors in the socket. To
remove a tube, rotate it counter-clockwise and then pull it up out of the
socket.
Step 2
Ensure that the anode connector is tightly clamped to the tube.
Step 3
Ensure that the silicon-rubber exhaust chimney is straight and that the
bottom is firmly against the tube deck and completely covers the airflow
opening in the deck.
The chimney should be flush with the top cover when it is placed back on
the amplifier. Tube-cooling exhaust must exit only through the tube anode
fins; it must not be allowed to escape outside them.
IMPORTANT:
Damage caused by insufficient cooling
airflow is not covered under warranty.
4.4 Connect the Voltage Tap
Selecting the appropriate tap for your situation optimizes amplifier
performance, safety, and lifetime.
!
IMPORTANT
We strongly recommend that you operate the amplifier on 240 VAC.
If you choose to do otherwise, see
Section 3.2, “Limitations of
Operation at Nonstandard Voltage,” page 3–4
.
The primary voltage taps are located on the top of the mains board,
between the transformer and the front panel.There is a row of five “fast-
on” connectors (J22 to J26) and a flying jumper connector that mates with
them (see
Figure 4-1
).
