Philips Hdt 8520

[ask100]

Since the recent changes to Freeview I was able to retune my TVs to access all the HD and SD channels as before. However I use a number of Philips HDT 8520 boxes to record programmes and have not been able to tune into a number HD channels such as BBC4 on 106 and Al Jazeera on 108 plus others.
What I get is a Signal Lost message.
Philips appear not to have supported this model for some time. Do any members have suggestions as to how to solve this tuning problem.
I appreciate that the alternative is to buy new boxes, but at great expense!
if it comes to this would members recommend Panasonic or Humax for the job?

[Buenchico]

The multiplexes (= channel bundles) used by BBC Four, Al Jazeera, etc have changed frequencies. Your aerial doesn't 'resonate' as well with the new frequencies as it did with the old ones, meaning that there's insufficient signal strength for your Philips boxes to 'lock onto' them. (Your TVs clearly have higher 'sensitivity' than those boxes, explaining why they can cope with the lower signal strengths, while the boxes can't).

[For a more detailed explanation, please refer to my first post here: https://www.theanswerbank.co.uk/Technology/Question1596727.html ]

So you need to improve the signal strength, either by using signal boosters (which should probably do the job) or by getting a decent aerial fitted on your roof. (You'll then need to carry out a re-scan on your Philips boxes).

[Postdog]

I have a Humax nearly ten years old where software hasn't been updated. However, I have no problems when needing to rescan because of changes to freeview. I do a complete rescan rather than trying to alter individual channels that need it. I don't lose any recordings either.

Thing is, I don't think it's down to software. I recall many years ago that the industry as a whole agreed that changes they make will NOT render any receiving equipment obsolete. I should think your equipment was not made prior to that, so should be capable of successful rescans.

[ask100]

Thank you for your informative response Buenchico.
However my aerial is less than two years old and last week I had a booster fitted.
My Philips HDT 8520 allows Retune or Automatic update. Retune won't bring up any of the missing channels. I've tried it a number of times. I imagine the Humax box is different in this respect Postdog.
I think I will take the box out and see if I can get a different outcome by tuning in elsewhere.

[Buenchico]

Which transmitter do you get your signals from?

[ask100]

Sorry for the delay in answering Buenchico.
I reside in Hendon NW4 so I guess it is Crystal Palace.
How do I check?

[ask100]

Yes, it is Crystal Palace.

[tamborine]

I had a flash up today to retune freeview on 18th April to receive missing channels. I cant find where the flash came from but it was directed at my London Signal.

[Buenchico]

Thanks for your reply, Ask100.

Quote (re the Crystal Palace transmitter):
"The multiplex carrying BBC News HD, Al Jazeera HD, 4seven HD and Channel 4+1 HD among other channels (multiplex COM7) is changing frequency on 7th March 2018- from UHF channel 33 to the new national frequency on UHF 55. It has reduced coverage and is only available on newer Freeview devices. A wideband aerial is required to receive these services reliably"

Source:
https://www.a516digital.com/2018/03/freeview-changes-in-london-21st-march.html

Carry out yet another search channels, Ask100, but then press the yellow button to enable the 'Check' function. Use the Up and Down buttons to select 'Channel UHF 55 (746MHz)' and take a look at the signal strength bar.

As I've suggested above, I strongly suspect that the signal strength will be shown as inadequate. The aerial you had fitted a couple of years ago was probably a narrow band one, which covered UHF Channel 33 and its neighbouring channels adequately but which wasn't designed to handle the far higher frequency used by UHF Channel 55.

So it seems likely that you'll now need to get a wide band aerial fitted.

[Buenchico]

^^^ Minor typo:
"Carry out yet another search for channels . . . "

[Buenchico]

PS: Don't let your aerial installer select your new aerial. Order one of these and then get him to fit it for you (unless you're happy to do it yourself, of course):
https://www.amazon.co.uk/Tri-Fold-Element-Analogue-Digital-Antenna/dp/B005DD59D2

(NB: That recommendation isn't just based upon a bit of googling. I live in an area with very poor TV reception, where every house has a big aerial mounted up on a high pole. Loft-mounted aerials simply don't work here at all. However when my own roof top aerial fell down I couldn't afford to pay an aerial fitter to install a new one, so I did a lot of research to find the very best aerial on the market and tried it in my loft. Amazingly, despite being lower down than all my neighbours' aerials, and having three brick walls directly in front of it, I got it to work! So it's that same aerial which I'm now recommending to you)

[ask100]

After a bit of a gap I'm back on the case.
Buenchico, I have checked again and find that Channel 55 strength is excellent. But I still cannot get the HD channels up!