Freeview trouble

Dajoca

Standard Member
Background...
I have a Panasonic 42" plasma with built in Freeview and even though I live on the edge of Dartmoor, I can pick up a huge number of channels from the Caradon Hill transmitter.
The BBC ones register as a 10 out of 10 for signal strength.

Now the problem...
My parents have just bought me a Samsung BD-D8500M.
Using the same aerial lead as the tv, I could only pick up 10 tv channels and no BBC channels at all.
I suspect it may be a rubbish aerial in the attic, but the fact the the TV receiver tells me I have a great signal strength on BBC, yet the Bluray player can't even see them has upset that argument.

Any ideas please?
 

lbear

Well-known Member
There can be difference in the sensitivity of different tuners within the same maker's range so between different makes is common. Separate STBs tend to be more sensitive than built in tuners. You may have too strong a signal for the Samsung bearing in mind what appears to be a max on your Panasonic. If you have a signal indicator it may show this by a high signal strength but low quality. A variable attenuator would solve that problem.

Another thing (and worth trying first) is that HDMI leads can emit RF so either moving the aerial lead away from the HDMI lead or temporarily using a SCART connection (if you can) may confirm this as the cause.
 

Dajoca

Standard Member
I'll give those options a go tomorrow. It just seems counter intuitive to me that a signal being too strong could cause the receiver to not even see the channels.

Just been online looking at the transmitter locations relative to me (Caradon) and while I remember seeing the old aerial in the attic a long time ago, I would swear it wasn't pointing anywhere near the proper direction that it should do according to the info I've found tonight, so that's another thing to check tomorrow.

Thanks again for the help.
 

grahamlthompson

In memoriam
I'll give those options a go tomorrow. It just seems counter intuitive to me that a signal being too strong could cause the receiver to not even see the channels.

Just been online looking at the transmitter locations relative to me (Caradon) and while I remember seeing the old aerial in the attic a long time ago, I would swear it wasn't pointing anywhere near the proper direction that it should do according to the info I've found tonight, so that's another thing to check tomorrow.

Thanks again for the help.

Like all things tuner design is a comprimise, the more sensitive it is at copeing with low signal strength the less it can cope with much higher signal levels. Digital tuners can cope with very low signal levels hence the proliferation of high gain aerials and amplification to get Freeview Pre DSO.

At DSO the power goes up 10dB. All that extra power together with the measures required to hang on to the weak pre-dso signals it's a surprise that many more don't have the problem.
 

Dajoca

Standard Member
Had a look at the aerial in the roof space and it's about 6 feet long and pointed in the right direction.

Tried reducing the signal strength and just got no/weak signal warnings.

Used a shorter RF lead between the socket and the box and got a few more channels including BBC.

Removed the HDMI lead once tuning had started and got all of the channels (I think) including the HD channels I was hoping for. :D

I am in a Group A region, so would a Yagi18A or a Log periodic make a difference to the reception, or would that HDMI interference also just corrupt the signal from a "proper" aerial?

Thanks again for the help and hopefully it can also help someone else who stumbles onto the same problem.
 

Chris Muriel

Distinguished Member
Can you relocate the HDMI lead or replace it with another ?
Although it's counter-intuitive, a cheap poundshop or similar HDMI lead has been known to solve HDMI radiation problems on several occasions.
 

grahamlthompson

In memoriam
Using double screened satellite grade coax cable (WF100/PF100) can also help.

Changing the aerial is unlikely to help.
 

Dajoca

Standard Member
I'm just about to order 25m of WF100 to make sure that the aerial lead and therefore signal strength, is as good as it can be, but for now I've got it sorted with a bit of tinfoil..

Unplugging the HDMI lead was not a viable solution, so I replaced both the HDMI lead and the RF lead, but got the same result.

I then re-reouted the RF lead but still got interference until I wrapped the HDMI lead in tinfoil from where it enters the cabinet to where it enters the receiver.

A bit Heath Robinson, but it seems to have solved the issue until I can replace the coax and get the RF signal strong enough to fight back against the HDMI bully..

Nice of Samsung to place the HDMI and RF sockets right next to each other though.

Thank you to everyone for your help.
 

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