Thank you everyone for your input on this. Eventually i just used a piece of wire 82mm long and bent it over and stuck it out of one of the slots in the housing. Crude i know but the initial results are promising. The Gateway is in one corner of the house upstairs and i placed the sensor in the opposite diagonal corner downstairs in the house through a guess of 4 brick walls and the sensor is reporting an Rssi of -65db ti -70db. Shame Rssi can not be presented in Domoticz properly yet (Having to use a dummy sound sensor to visualise it) as mysensors has no way of handling it yet!. I will be conducting more range tests but the change from NRF24 was well worth it (No more deadspots in the house).

No. You shouldn't have to. That's the max number of clients allowed to connect simultaneously and I guess 1 is enough.