Freeview signal problem

Decky63

Standard Member
Can an aerial expert advise on my Freeview signal problem please? I have a Panasonic Plasma TV which has worked with Freeview problem-free for several years but just lately I've been getting frequent signal drop outs, mainly on the HD channels. When I monitor the signal condition on the TV, both the strength and quality stay at 10/10 but the quality keeps dropping to zero for about a second or so and then returns to 10.

The aerial is on a tall mast on the roof which feeds into an aerial amplifier in the attic which then loops through a Freeview recorder and then into the TV. The drop outs only happen on the TV, not on the recorder which is first in the loop. I checked all the connections and they look ok (though if it was a dodgy connector I would have expected all or nothing).

Any suggestions please?

Thanks
 

SyStemDeMoN

Well-known Member
Im no expert but experienced problems at our caravan.
In the end I just replaced the cable from the antenna to the humax box and now all is well.
Could be a break in one of the cables.
 

Terry Maher

Active Member
I have noticed a similar problem on my Samsung HU7500 TV which I have posted on that forum, so you may like to read some of my posts and others replies on there. Whether its relevant to your Panasonic problem I don't know, but it may be worth investigating

See the link below for a 'flavour' of what I found

Samsung **HU7500 owners thread
 

Old Bones

Active Member
but just lately I've been getting frequent signal drop outs, mainly on the HD channels. When I monitor the signal condition on the TV, both the strength and quality stay at 10/10 but the quality keeps dropping to zero for about a second or so and then returns to 10.

Quality of signal should be 10, but signal strength is another matter. According to UKFree.TV, 70% is pretty much perfect. Before switchover, people often got boosters, etc, because signal strength was possibly a little low. Once switchover was complete the strength (about 10% of the analogue strength) started to climb, and retunes, upgrades etc tended to have a lot of people complaining of exactly the same thing you are. Signal strength is around 90% of analogue.

Panasonic's are well known for sensitive tuners anyway (Sony, Humax and Samsung as well), and that, plus increased signal strength, plus an amplifier, can mean dropouts as the tuner is overloaded. HD tends to be hit first - my cheapo HD box certainly had that problem for a while, because its surprisingly sensitive.

If you can take the amp out of the system, see if it settles down. Remember your looking at around 70-75%. Follow the UKFree.TV link, and have a look at DigitalUK's website, just to see how close you are to the transmitter. I've over 50km from mine and I have to use an attenuator to bring the strength down to a usable level, so its perfectly possible to have this problem, even though you dont think your all that close.
 

Terry Maher

Active Member
Quality of signal should be 10, but signal strength is another matter. According to UKFree.TV, 70% is pretty much perfect. Before switchover, people often got boosters, etc, because signal strength was possibly a little low. Once switchover was complete the strength (about 10% of the analogue strength) started to climb, and retunes, upgrades etc tended to have a lot of people complaining of exactly the same thing you are. Signal strength is around 90% of analogue.

Panasonic's are well known for sensitive tuners anyway (Sony, Humax and Samsung as well), and that, plus increased signal strength, plus an amplifier, can mean dropouts as the tuner is overloaded. HD tends to be hit first - my cheapo HD box certainly had that problem for a while, because its surprisingly sensitive.

If you can take the amp out of the system, see if it settles down. Remember your looking at around 70-75%. Follow the UKFree.TV link, and have a look at DigitalUK's website, just to see how close you are to the transmitter. I've over 50km from mine and I have to use an attenuator to bring the strength down to a usable level, so its perfectly possible to have this problem, even though you dont think your all that close.
Thank you Old Bones !!

You've summed up perfectly what I was trying to refer to in my Samsung posts.

I too looked at the UKFree.TV website and concluded that an attenuator was the solution........ and it worked !!!!
 

Old Bones

Active Member
They are pretty cheap as well - a fixed one is less than £2 from Amazon. If you buy them at different strengths, you can put them in series to get just the right level. The variable ones havn't always worked for me, but they seem fine.
 

Decky63

Standard Member
Many thanks for all the replies, you're all aerial experts in my book (I never considered that it could be caused by a signal level that's too high). I took the amp out by connecting the in and out cables together but was surprised that it resulted in no signal at all, I would have thought there would have been something (I checked and rechecked the connections). So I put the amp back in (signal back as it was) and turned the gain down instead (same as fitting an attenuator?) so that the strength showed a constant 7/10. But instead of staying at 10 and dropping out now and then, the quality is now jumping between 6 and 10 and still dropping out the same. Could the amp be at fault?
 
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grahamlthompson

Distinguished Member
Many thanks for all the replies, you're all aerial experts in my book, I never considered that it could be caused by a signal level that's too high. I took the amp out by connecting the in and out cables together but was surprised that it resulted in no signal at all, I would have thought there would have been something (I checked and rechecked the connections). So I put the amp back in (signal back as it was) and turned the gain down instead (same as fitting an attenuator?) so that the strength shows a constant 7/10. But instead of staying at 10 and dropping out now and then, the quality is now jumping between 6 and 10 and still dropping out the same. Could the amp be at fault?

You haven't by any chance got a masthead amplifier (a separate box mounted close to the aerial). If so they require a power supply which your amplifier may be providing. The attenuator in your amp may only reduce the output levels, which will be no help at all if the front end of the amplifier is clipping the signal. I would try a variable attenuator on the amplifier input.
 

Decky63

Standard Member
Thanks Graham, good thought. I checked with binoculars, there's a black box on the mast that looks to be about 3" square but I can't tell whether it's an amp or a connector box. As you say, it would explain why there's no signal with the amp in the attic removed and why the gain needed to be set to near minimum to achieve 7/10. So I've ordered a variable attenuator with dc pass and will report on what happens.
 
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Decky63

Standard Member
Ok, I've fitted the new attenuator on the amp input (marked 'IN') and tried various settings. With the attention at maximum (20dB) and the amp gain now turned up to around the middle I'm getting a signal level of 7-8/10 but still getting signal drop outs at the same rate as before (when the signal quality bar momentarily drops to zero and the screen flashes up 'No signal'). Any more thoughts please?
 

Trollslayer

Distinguished Member
That sounds like interference.
Is there any electrical equipment nearby that switches one and off quite a lot?
Even a fridge could cause this.
 

Decky63

Standard Member
I found that the Fire TV Stick installed behind the TV on loose leads had fallen down and was resting on the aerial socket, moving it away cured the problem. Many thanks Trollslayer and to everyone for all the help and suggestions.
 

Terry Maher

Active Member
Ok, I've fitted the new attenuator on the amp input (marked 'IN') and tried various settings. With the attention at maximum (20dB) and the amp gain now turned up to around the middle I'm getting a signal level of 7-8/10 but still getting signal drop outs at the same rate as before (when the signal quality bar momentarily drops to zero and the screen flashes up 'No signal'). Any more thoughts please?
From memory on my Samsung TV, an improvement wasn't immediately apparent after fitting the attenuator, so I also did a 'factory reset', and re-tuned all the freeview channels, so it might be worth trying either one or both of these

Out of interest, are the drop outs only occurring on the HD multiplex channels (look at ukfree.tv for details of these in your area). I found that my dropouts were limited to these channels (ie ones that used the DVB-T2 tuner), and may also include non HD channels like Film 4+1 (ch 45 in my case). UKfree.tv will list these for your area.

Oops sorry, hadn't seen Trollslayers post or your reply !!!
 

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