New TV doesnt get HD freeview channels but old tvs do from same coax

kryten22uk

Active Member
Bought a new Philips LED TV (75PML9506) and did the usual channel scan. It gets all the non-HD channels (120ish) but non of the HD ones. I have a couple other TVs in the house and if I move them next to the new TV and plug them into the same coax aerial, they get HD channels just fine.

I've tried a software update.
I've tried turn off and on again.
I've tried unseating and reseating the cable.

My local transmitter is Tunbridge Wells and i should get a good signal for all channels. I tried to look up the details and apparently HD channels from that transmitter are channel47 on 682Mhz (according to Tunbridge Wells (Kent, England) Full Freeview transmitter). The Philips TV allow me to test digital reception by MHZ frequency, but when I enter 682MHZ, it simply says zero channels, zero signal quality and zero signal strength. Sounds suspicious, seeing as my other TVs have great reception quality for HD.

Any ideas?
 

tvdavid

Well-known Member
says defo DVB-T/T2/T2-HD/C/S/S2 so its really strange why this one don't get them.
 

kryten22uk

Active Member
Also just tried the fix where you do a scan after removing the coax aerial so as to delete all channel history. But afterwards the rescan still only brought in the SD channels.
 

mikej

Well-known Member
What is the signal strength for UHF 47 on a TV that picks it up fine ?

If it's not particularly strong, it's possible that the new Phillips TV has a higher threshold for picking up and tuning into weaker signals than the other TV(s). It would be odd that it says zero though admittedly, if that was the case. You would expect to see something registering.

Could it be a faulty tuner ?
 

JayCee

Distinguished Member
If you have any equipment connected to it via HDMI unplug the cable at both ends and try retuning again.
HDMI cables have been known to radiate spurious RF knocking out some Freeview channels and sometimes whole MUX’s
 

kryten22uk

Active Member
If you have any equipment connected to it via HDMI unplug the cable at both ends and try retuning again.
HDMI cables have been known to radiate spurious RF knocking out some Freeview channels and sometimes whole MUX’s
Good idea thanks. I was quite optimistic as the scan produced more channels than previously (137 digital channels). Unfortunately the HD ones still not appearing. ☹️
 

kryten22uk

Active Member
Yep, nothing after the 700 radio stations.
 

mikej

Well-known Member
Checking the signal strength for UHF 47 on a TV that tunes into the HD channels without any issues might help with your trouble-shooting. If it's low (below 70 %, for example) then it could, in my experience, be a tuner threshold issue.
 

kryten22uk

Active Member
What is the signal strength for UHF 47 on a TV that picks it up fine ?

If it's not particularly strong, it's possible that the new Phillips TV has a higher threshold for picking up and tuning into weaker signals than the other TV(s). It would be odd that it says zero though admittedly, if that was the case. You would expect to see something registering.

Could it be a faulty tuner ?
What is the mhz frequency for UHF47? I can only test via frequencies rather than channel numbers. I did find the website in the OP that said 682mhz, but that might not be correct.
 

mikej

Well-known Member

kryten22uk

Active Member
Thanks. And is it def ch47 for the HD channels?
 

kryten22uk

Active Member
Ok so I tested the signal on another TV plugged into the same coax. It is signal strength 95 and quality 100.
20211226_140644.jpg
 

kryten22uk

Active Member
Then the signal test for 682mhz on new TV show zeros. Weird.
20211226_141147.jpg
 

mikej

Well-known Member
Thanks. And is it def ch47 for the HD channels?
I don't know - I was going on the fact you mentioned it was :)

If you put your postcode and house number into the checker on this Freeview site and hit 'check', it'll give you a table with your nearest and most likely transmitters, along with separate tables below that of the frequencies they broadcast at, along with the predicted coverage.

BBC B (PSB 3) is the mux that carries the 1-5 HD channels and others and for the Tunbridge Wells transmitter, that does appear to be UHF 47.
 

mikej

Well-known Member
Ok so I tested the signal on another TV plugged into the same coax. It is signal strength 95 and quality 100.
View attachment 1625089
That signal strength appears to be really good, which lessens the chance of it being a tuner threshold issue I think. Oh well - it was worth trying to rule that out.
 

mikej

Well-known Member
Then the signal test for 682mhz on new TV show zeros. Weird.View attachment 1625094
That is really odd. You're happy that the cable is connected properly when scanning ? It picks up the other UHF channels from your transmitter without any problems when performing the same signal strength test ? I would check.

I have an older Humax PVR on which I have to select DVB-T (SD) or DVB-T2 (HD) when checking signal strengths so scanning an HD mux like channel 47 but with DVB-T (SD) selected would give no results - does the Philips TVs allow the same choice when doing a test ? It doesn't look like it from your screen-shot, but I thought it was worth mentioning as it would result in the same readings you're getting.
 

kryten22uk

Active Member
No there's only one scan option that says "DBV-T", albeit in the description it refers to DBV-T/T2. So a joint SD/HD scan I imagine.

All other SD channels have the same 100/95 signal strength and quality. So can't see it as an aerial/connection issue.

I am thinking it can only be an issue with the TV receiver then. Need a return replacement.
 

Rodders53

Distinguished Member
Sorry I'm late to this thread. Just spotted it.

It may be signal overload (i.e. too much signal) on the new set's tuner? {Tho normally I'm not one to suggest that ;) }

Any aerial amplifier involved? If it has a variable control turn it down a bit and try again?

If you can temporarily bypass the amplifier to feed the new set direct from the aerial to tune in (then don't do it again if all channels found). It'll allow better fault finding /tests to be performed.

A 2-way passive splitter will reduce the signal by a bit over half (-4 dB) if you have one. Alternatively attenuators can be bought and used to lower the signal.
 

kryten22uk

Active Member
Sorry I'm late to this thread. Just spotted it.

It may be signal overload (i.e. too much signal) on the new set's tuner? {Tho normally I'm not one to suggest that ;) }

Any aerial amplifier involved? If it has a variable control turn it down a bit and try again?

If you can temporarily bypass the amplifier to feed the new set direct from the aerial to tune in (then don't do it again if all channels found). It'll allow better fault finding /tests to be performed.

A 2-way passive splitter will reduce the signal by a bit over half (-4 dB) if you have one. Alternatively attenuators can be bought and used to lower the signal.
thanks for the ideas. Unfortunately I've already sent the TV back. If/when they send a replacement, and if I get the same issues, I will test your suggestions. We do indeed have a signal booster/splitter as well as a further passive triple splitter along the path. We have nonetheless had 4 new TVs over the years that have all faultlessly tuned in all channels using this setup (brands incl Samsung and LG but this is the first Philips).
 

kryten22uk

Active Member
Sorry I'm late to this thread. Just spotted it.

It may be signal overload (i.e. too much signal) on the new set's tuner? {Tho normally I'm not one to suggest that ;) }

Any aerial amplifier involved? If it has a variable control turn it down a bit and try again?

If you can temporarily bypass the amplifier to feed the new set direct from the aerial to tune in (then don't do it again if all channels found). It'll allow better fault finding /tests to be performed.

A 2-way passive splitter will reduce the signal by a bit over half (-4 dB) if you have one. Alternatively attenuators can be bought and used to lower the signal.
Well I got a replacement TV delivered and exactly the same issue. No HD channels tuned.

I removed the signal booster as suggested but unfortunately didn't make a difference. Noticeably poorer signal in general on the SD channels but still no HD channels tuned. 😢
 

tvdavid

Well-known Member
I sold an old tv a Phillips light up one the other day this one
It would not work around the flat yet the man's small tv did
however it works perfectly on my tv aerial.
was just the next road up as well.
hope it works better for the next person.
 

Rodders53

Distinguished Member
What do Philips support and/or the retailer support people say?

Have you tried using a different aerial fly lead(or leads), connecting TV in different room(s). Or a long fly lead from another room's outlet. In a different place within the same room (if wall mounted on its stand elsewhere). With only the TV aerial connected and all other peripheral components disconnected. mains disconnected. On a neighbour's aerial, perhaps?

This is extremely perplexing, though.
 

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