Location - QRO Technologies HF-2500DX Instruction Manual

which can deliver adjustable output power from 0 to 100 watts. A grid driven input circuit using
a 50 ohm 100 watt non-inductive shunt resistor feeds each 4CX800A tetrode tube which are
connected in a grounded cathode configuration. An ALC circuit develops negative voltage that
can be fed back to the transceiver to reduce its gain when the amplifier is overdriven. The
antenna transmit-receive (T/R) relay is normally actuated by relay contacts, or an electronic
switch, in the transceiver to place the amplifier in the transmit mode. The relay contacts must be
connected to ground. Operation problems will occur if the contacts have more than zero volts
DC. A +15 VDC contact is provided for transceivers utilizing a + 15 VDC on transmit for T/R
switching.
Do not operate the Amplifier in excessively warm locations or near heating vents or radiators. Be
sure air can circulate freely around and through the Amplifier cabinet, and can provide an
unobstructed air inlet for the internal cooling fan. Do not place any books, magazines, manuals,
or equipment that will impede the free flow of air near the sides and the hot air exhaust holes
located on the top of the cabinet. The internal fan allows an air flow of approximately 50 CFM. Do
not use an external auxiliary cooling fan with less than 50 CFM capacity. The exhaust air
becomes quite warm at high power levels. Do not position any heat-sensitive objects in the
exhaust airflow path.
Before operating the amplifier, verify that the AC Voltage Power Block located inside the amplifier
has been wired correctly for the local AC supply you will be using. See the Voltage Power Block
Wiring Diagram for the correct wiring. Make sure the AC line cord has been disconnected and
filter capacitors have no charge on them before removing the top cover.
Verify that the rating of the line fuses located in the rear panel fuse holders is suitable for the AC
line voltage you will be using. The fuse should be the glass cartridge slo-blow type. The rating
should be 20 - 25 Ampere.
Use only AC power outlets having a protective ground for connection to the amplifier. DO NOT
USE 2 conductor extension cords or 3 prong to 2 prong adapters that do not provide a protective
ground connection. Connection of the power cord to the power outlet must be made in
accordance with the following standard color code:
Use the following NEMA plug configuration: 200/240 VAC 20 Ampere 6-15P or 6-20P
Due to the power involved, this Amplifier should have its own 240 VAC electric service line. This
line should have three 12-gauge conductors, and 20 ampere fuses in each "hot" wire. If a single
240 VAC line serves the entire station, make an effort to connect your equipment so the load is
balanced between the two "hot" wires. DO NOT use this Amplifier at it full ratings on a regular

LOCATION

AC LINE POWER CONSIDERATIONS
American
Live Black
Neutral White
Ground (Earth) Green
European
Brown
Blue
Green/Yellow
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