QCX acceptable load mismatch?


Johan Bodin
 

Hi,

is there any knowledge/experience about how much abuse the QCX PA can withstand without damage? If a low loss SWR meter is used, the impedance seen by the PA will deviate wildly from the 50+j0 ohm target while searching for a perfect match with an antenna tuner. I am currently using a -6dB resistive SWR bridge (three 50 ohm resistors + a detector) while tuning so the worst case load seen by the QCX goes from 33 to 100 ohms when the load at the bridge output goes from shorted to open. Can I assume that this is safe?

My Mini is still alive and well but the lack of PA protection makes me a little worried. I just want to prevent failure in the field when messing around with makeshift antennas :)

73
SM6LKM

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