TV reception issue

bobblebob

My uncle has a TV with built in freeview, and a PVR with freeview. I retuned both the other day as some channels were getting moved around on freeview. Since then the PVR freeview has signal problems with channels 3,4,5 and 6 (poor signal strength and signal breakups). All other channels are perfect with 100% signal.

Thinking it was some dodgy cable or aerial, i did some testing. I plugged the aerial from the roof directly into the TV freeview and channels 3,4,5 and 6 work perfect, so i know the aerial is ok. Plugging the aerial directly into the PVR freeview and we get poor signal quality on those channels.

So why do those channels work fine on the TV and not on the PVR with the same aerial and cable, and why has this only happend since the rescan? Is it possible the tuner in the PVR is playing up?

System

Possibly the pass through or internal amplifier in the PVR is giving up the ghost. You can't just split an antenna feed into two and feed two separate devices as it both alters the impedance of the cable and reduces the signal level both of which mean far poorer reception so devices like a PVR either have a matching circuit or their own internal amplifier to deal with this and this isn't a happy bunny.

Now to the other point. Coax has a lifespan of 7 years, most peoples is far older than that. Corrosion and water ingress are a real issue as time goes on and you could find the antenna end of the coax is in a really sorry state which degrades the signal. Also many older TV antennas were made for either the lower end or the upper end of the TV broadcast band so would give very poor reception of frequencies they weren't designed to receive. If the TV has a good internal pre-amplifier then it could be that the TV is able to amplify what signal it is getting sufficiently enough for the tuner to be happy but that the PVR's internal amp isn't. If the TV had an antenna out socket you could test this by feeding the PVR from the TV's antenna out or if not by buying a powered TV antenna splitter which has an amplifier built in.

bobblebob

Whats strange is the PVR was working perfectly up to the rescan. Will do some more testing but the aerial and cabling isnt that old

bobblebob

Brought the PVR to my house and it picks all channels up with full signal. So that means the box is fine, so it looks like its the aerial on my uncles rough that is playing up

artyclarty

It would be helpful to know what the make and model of the PVR is, may help, yet it may not too!

Do you use HDMI cables to connect the PVR (and any other peripherals) to the tv? Cheap ones are known to cause signal gremlins. Move the cables apart and see if that makes any difference.

bobblebob

Its an old Humux PVR (6 years or so) so only connects via Scart.

Rang a local aerial man up, he seems to think its the PVR tuner playing up, but he says he will bring a spare box with him to test before doing anything with the aerial. Noticed when i went to my uncles today that the splitter for the aerial (he has 2 tvs feeding off 1 aerial) is outside, so could possibly be that thats weather damaged

Rodders53

Location? Where is Uncle? What transmitter(s) can be received? {Smart money is on Winter Hill / Moel-y-Parc area}

Almost certainly the auto tune on the PVR has picked up a 'wrong transmitter' for the ITV multiplex, but not the others... see if better quality ones of the lcns 3, 4 & 5 are stored in the 800s on it. 6 is a local TV multiplex and generally weaker but might have a similar issue in some places.

If so, a 'manual tune' to the correct transmitter will sort it.

http://www.digitaluk.co.uk/coveragechecker/manual_retuning

bobblebob

He is on the Emley Moor mast. Lives about 5 mins from me. Can see the mast from his house so not far away

I didnt notice at my house the frequency of the channels he struggles with were different than when i scanned at his house so maybe the tuner is picking the wrong one up

Will try a manual scan

bobblebob

Did notice sorry