For a long time everyone has suffered shocking TV reception at the units where I live. Sometimes it's crystal clear, then channels randomly disappear for a week or so. We've put it down to being in a black spot, the antenna being crap, the wiring being crap, trams and various other causes (maybe the piano interferes...!?)
A month or so ago, one of the residents, Mary, got fed up and called an antenna guy to come and have a look. He actually knew what he was doing and diagnosed the problem to be that signal booster #1 was sending far too powerful a signal into booster #2, making booster #2 overload and fail.
Installing a simple resistor to lower the signal going into booster #2 resulted in perfect reception on all channels and no artefacts when a tram went by.
As of about an hour ago, I have three tuners, each of which is capable of recording two simultaneous streams. I think the raid array wouldn't cope if it tried to record six shows at once, but then again the chances of there being six simultaneous programmes worth recording is zero.
I can now at least record shows on both the ABC and SBS at the same time and still have a tuner spare for the odd occasion there is something worth spending time watching on channels 7, 9 or 10.