Instruction manual

AL-800 Instruction Manual
27
PIN diode options that permit operation on modes requiring high speed receive-transmit switching.
Both systems offer noiseless switching times of under one millisecond. Since these PIN diode
systems are several times faster than vacuum relay systems, they will allow over 90% of the
available receive time to be used at 60 WPM.
Ameritron highly recommends using the external QSK-5 switch. This stand alone PIN diode switch
can be used with almost all types of amplifiers and transmitters. Modifications are not required in
amplifiers used with the QSK-5 unit. The QSK-5 operates directly from 120 Vac power lines.
Ameritron also offers an internal QSK board as a space-saver for the AL-800. This internal board is
slightly less expensive. However, it provides less flexibility and serviceability than the external
QSK-5 unit. Factory installation of the QSK-5PC is highly recommend. Contact Ameritron for
details on the QSK-5 and the QSK-5PC.
Periodic Maintenance
The high voltage present on various parts of the amplifier will attract dust and dirt. The high
voltage areas at the bottom of the plate choke and the plates and insulators of the air variable
capacitors should be kept dust free. These areas should be inspected periodically, especially if the
amplifier is operated in a dusty environment. These areas may be inspected by unplugging the line
cord and waiting a few minutes for the power supply capacitors to discharge. The high voltage
should then be checked with the internal multimeter by placing the meter switch in the HV position.
WARNING:
High voltages can kill!!! Accidental contact with the voltages in this amplifier can be lethal!
For your personal safety please observe the following precautions:
1.) NEVER
defeat the interlock.
2.) NEVER
remove the cover with the amplifier connected to the power line.
3.) ALWAYS
allow the capacitors to discharge for several minutes after unplugging the amplifier
and before removing the cover.
4.) ALWAYS
select the high-voltage (HV) function of the Multimeter to check the high voltage
potential. Do
not
remove the cover if voltage is indicated.
5.) ALWAYS
ground the tube anodes (outer metal surface) to the chassis before touching anything
inside the amplifier.
6.) ALWAYS
be cautious of heat. Many components inside the amplifier operate at high
temperatures.