AKG WMS 40 Mini Dual Vocal

This set looks very nice and promises a very good value for the money.
I have bought two sets, both have the same problem - and officially it is not an equipment failure: it is just like that, it works like that.
When channel one reception is disturbed it outputs an enormous popping noise at such a high level, that I was wandering whether my speakers will blow or not...
Channel two reception works much better, and it never outputs this unbelievable noise. OK, it is a non-diversity receiver, but this phenomenon is not acceptable in any case. This is why I decided to return the product.