8
during return shipment.
INTRODUCTION
The QRO Model HF-2000 Linear Amplifier is a completely self-contained, grounded grid, linear
amplifier. It is designed to operate at 1,500 watts PEP output on SSB, 1250 watts on CW, and
1000 watts on such high duty cycle emissions as RTTY, SSTV, and FM. The HF-2000 is designed
to be used with any transceiver which will deliver 120 watts or more output. It can be used with
less driving power, but it will have a lower output. A broad-band tuned input circuit for each band
feeds the 3-500 triode tubes which are connected in a grounded grid 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.
LOCATION
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 andthe 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.
AC LINE POWER CONSIDERATIONS
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 disconnect 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 either of the following:
120 VAC
20 Ampere
240 VAC
10 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:
American
European
Live
Black
Brown
