Electromagnetism vs. The BBC
September 16, 2007 1:55 PM Subscribe
TV Signal Problem: Co-axial cable suffering EM interference (I think), and it only affects the good channels!
posted by boosh to technology (6 answers total)
I recently built a Home Theater PC and it works perfectly except for one thing: some of the TV channels suffer from terrible interference, ranging from stuttering to total loss of signal. I'm receiving UK Freeview (from the Crystal Palace transmitter 30-odd miles away) through a Hauppauge WinTV Nova Digital Freeview PCI card. The current cabling is standard co-ax from the roof aerial, which comes into the house and runs through a couple of boosters and then through whatever el-cheapo co-ax cable came with the boosters into the TV card. The same signal also goes direct into my digital TV and provides a flawless reception. The HTPC box is tucked into a corner behind the TV cabinet.
The whole BBC output is affected (i.e. BBC 1 through 4 and News24) plus a few others (Five Life, Five US and abc1 but I'm not really bothered about them). All of the other digital channels are absolutely fine through the TV card.
However... if I pull the HTPC out of the corner, so the co-axial cable is at full stretch and away from all the other cables and power supplies, the signal problem instantly disappears, and all of the channels get a flawless reception. This leads me to think that I might be getting some kind of EM interference when all the cables are bundled up together in the corner. It's not an issue with one particular co-ax cable, as I've tested 3 different ones (although they're all the same standard quality cables).
Repositioning the unit or the route of the cable is not really an option, so I guess that I need a cable with better shielding to keep the interference out (but please correct me if I'm wrong). I've done a load of googling and come across options like 'quad shield RG-6' and 'triaxial', but what do I actually need and where can I get it in the UK? My bullshit meter always goes haywire when I browse any site selling cables and interconnects, so recommendations would be greatly appreciated.