User's Manual

11
Control Cable
Control cable maintains TX / RX switching of the PA (TX GND). The cable is shielded. On the side
of the power amplifier a CINCH-socket is used. On the side of your transceiver you have to use a
socket suitable for this transceiver. During transmitting the middle pin is connected to the ground.
The relays of the OM2000A+ have to be switched earlier than HF is applied (cold switching).
Modern transceivers they have a time delay between PTT switching and power output.
If you are using an older transceiver or transmitters without time delay, we
recommend to connect the PA in such a way that the transmit/receive switch (foot
switch for example) is connected with the KEY IN socket of the amplifier. The KEY
OUT socket is to be connected with the PTT socket at the transceiver.
The amplifier is equipped with safety devices, which ensure that the output relay is not switched
under power mistakenly (hot switching).
KEY IN RCA Phono - Input signal PTT switching voltage / current - 5V /2mA)
KEY OUT RCA Phono - Output signal PTT (maximum switching of 30V / 50mA)
See section 7.6. for Control and ANT/BPF connectors PIN-OUT.
Be sure that your power system is correctly wired and properly rated! To use
adequately sized and connected grounding system is also very important!
4.3. Cooling
The amplifier must be installed in such a way that free flow of hot air from the tube is
allowed. Do not obstruct air intake and exhaust areas of the PA.
The centrifugal blower provides the necessary cooling of the amplifier, even during long contests.
The blower is activated by switching the PA on and it is turned off when cooling is finished (approx.
1-5 min after switching off the PA depending on the temperature of the tube). Blower working mode
is programmable (3 modes). See page 19 for more details.
5. OPERATION
Before switching PA on, make sure that amplifier is grounded, antenna or dummy
load is connected, and line cord is putted to the outlet. Be sure you selected AC
input by 7.1.
Do not turn PA on for at least 2 hours after unpacking it and locating in its operating
location. Especially when amplifier is moved from a cold place to a warm one
because not visible condensation may develop, and this could result in damage to
the high voltage circuits.