You'll have to turn down the radio power to say 40-50 watts but I don't know for sure. If it is like most radios, the power out/amps drawn is not linear meaning that if it pulls 22A on 100W TX, it will not pull 11A on 50W TX.
A 100 watt transceiver only draws about 9 - 12 amps - depending upon if the fan is running or not and the model.
A 35 amp power supply is mininum requirement - since a 20 amp power supply will only supply about 12 amps of continous power - not enough for 100% duty cycle - needed for CW or digital modes.
Astron power supplies are Amateur Grade Equipment, communications grade equipment has a 100% duty cycle and also a larger termperature range which you can operate it under.
The Astron power supply is only duty rated to 32* F