Hi, on the TV upstairs I have a small amount of coax cable coming in from the aerial on the roof, then I have a coupler connected to another coax cable to running to the TV. However the connectors are of poor quality (mainly the part that grips the cable) so it is very loose. Also the coupler is poor quality. Could anyone tell me where to get some good quality, secure connectors and a decent coupler, or alternatively a better solution? Thanks.