The TX inrush can be up to 20 times the nominal current hence tripping of the MCB.
A way around it is to have a timing device controlling a relay, which at switch on, first put a high power resistor ( ± 4.7 Ohm 50 watts ) in series for about 1 to 2 seconds, than the relay will short the resistor and the TX has normal power applied.
The resistor can be built from five 10 watt 20 ohms ceramic wirewound resistors in parallel in a safe enclosure.
Because of the short interval time the resistors are on for hardly any heat is generated.
Similar systems have been used on high powered amps with large capacitors, when the TX at switch on is feeding basically a dead short at the output for a couple of cycles.