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must be switched earlier than HF is applied (cold switching). Modern transceivers have a time
delay between PTT switching and power output, we recommend setting the time delay to 15ms.
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 connected to the PTT
socket at the transceiver. If it is possible to adjust TX delay in your TCVR, set the delay to 15ms, please.
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)
Be sure that your power system is correctly wired and properly rated! To use an adequately
sized and connected grounding system is also very important!
4.4.
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 17 for more details.
