Radioddity PAX100 User Manual
Conditions of Operation:
1. The PAX100 requires a power supply capable of delivering 20Amps current at 13.8
Volts. If your power supply does not have the capacity to deliver 15 amps continuously,
do not use the amplifier until you have a suitable power source.
2. The PAX100 requires a resonant antenna on every frequency it can operate on. If the
antenna is not resonant, you will need an external Antenna Tuner. The tuner must be
able to present an SWR to the output of the amplifier of less than 2.0:1. The lower the
SWR is, the less chance of damage to the amplifier. Anything above 1.5: should be used
with caution. The final transistors specifications recommend not exceeding 2.0:1. The
internal tuner of the radio will not be useful then the amplifier is in use. If the SWR of the
antenna in use is much higher than 1.5:1, after sustained operation, the amplifier may be
damaged.At 2.5:1 or higher, the amplifier will be damaged and unusable until repaired.
If needed, the final transistors are available from general parts suppliers and are low-cost.
3. When using PAX100, please turn off the built-in antenna tuner of G90, otherwise
PAX100 will be damaged. (External tuner is allowed to use.)
4. The input power (from the G90) to the amplifier should never exceed 10 Watts; even
on SSB peaks. Driving the amplifier with an output from the G90 higher 10 watts will
result in damage to the amplifier.
5. Amplifier’s gain is large on 160 meters. Please reduce drive to 5 watts on 160 meters.
6. Output with an open circuit or short circuit is prohibited.
What You Need
To run an external power amplifier, you should have the following items:
1. A power supply capable of delivering 20 Amps, preferably with voltage and amperage
meters built in to monitor amplifier current draw and voltage under load.
2. An external antenna tuner capable of handling, at least, 100 Watts.
3. Be sure that the connection lugs on your DC cables connected to the power supply are
capable of delivering 20 amps. If they are not, they will heat up and you will have voltage
