200 WATT BAND II VHF FM POWER AMPLIFIER
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3. PRE–INSTALLATION
3.1 Amplifier Driver / Exciter
The Driver / Exciter needs to be compliant and set to the correct
frequency BEFORE the amplifier is powered by AC Mains
Under NO CIRCUMSTANCES should the amplifier be connected to a Driver / Exciter
where the RF output performance and specification is unknown. Such action could
be cause serious disturbance to the electromagnetic spectrum and in extreme cases
dangerous interference to air navigation and emergency services.
The amplifier requires a suitable driver / exciter with audio limiting and an RF output
of between 900mW and 1400mW (MAX) when loaded with 50 ohms. This must also
be equivalent, better or meet the specifications shown in European Standard ETS
300 384.
Before powering up the amplifier the frequency of the Driver / Exciter should be set
and checked. If the AC mains is not connected to the power amplifier, it is safe to
use the power amplifier BNC input as a dummy load for the Driver / Exciter. At this
stage, if possible, it would also be advisable to check the deviation and that the
audio of the Driver / Exciter is correct.
If you are using a transmitter driver supplied by another manufacturer, compliance
cannot be guaranteed. On completion of the installation it is necessary that the
engineer checks the RF output of the power amplifier for compliance.
3.2 Antenna
Incorrect Antenna can cause RF burns and levels of RF Exposure
above the recommended limits for personnel
Under NO CIRCUMSTANCES should the antenna be mounted and used at ground
level or within a few meters of personnel.
A tuned antenna with the 50 ohm coaxial cable should be used. This should give a
return loss ideally of 16dB (SWR 1.4) or better at the operating frequency. The RF
plug should be PL259 (UHF) or N type, depending which is fitted to the power
amplifier.
