Thank you for the fast answer! Sure, I've tried with other antennas (but I'm not sure that is half-wave, I don't know how to check)
And I've checked, my transmitters have 1,04 version, so yep, I'll try to find someone with xd-75 to update my stuff...
Opened the receiver box - nothing strange there, no capacitors blowed or something like this...
sending to service is too expensive... equal to buy new one unfortunately =( There are points at the plate to check some things like - signal tip, power tip etc... so may be support will consult me how to check hardware problems by self, otherwise - it is really too expensive to use Line6 for wireless, had sennheiser ew-300 for 7 years and NEVER had any problem with it... but the sound sucks you know ))))