All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Michael John Wales: Perhaps it is the case that at times the signal strength is going too high:
Freeview signals: too much of a good thing is bad for you | Digital switchover | ukfree.tv - 11 years of independent, free digital TV advice
There are a number of buildings that could be blocking your line-of-sight and maybe something is occuring at some times which causes a strong beam to be sent your way. This could be a reflection, refraction or diffraction.
| link to this comment |
julie: Not unless it is found to be tuned incorrectly - that is it is tuned to a transmitter other than Emley Moor.
If this is found then obviously it has retuned itself and taken it upon itself to use a different transmitter. Investigation needs to be made whether this feature can be disabled.
Where the signal strength screen, whilst on BBC One (or any standard definition BBC service) indicates that it is tuned to UHF channel 47 (682MHz) then it is receiving the signal from Emley Moor and will give you the best picture for that signal which is being fed into it. Retuning will simply result in the same outcome - it being tuned to C47.
If it is still tuned to Emley Moor then perhaps too high a signal level is the cause. Try installing an attenuator in the aerial lead so as to bring down the level:
TV Aerial Attenuator Variable 0-20Db Freeview Digital | eBay
VARIABLE ATTENUATOR TV SIGNAL REDUCER 20dB 3 5 6 9 10 12 15 18 DIGITAL FREEVIEW | eBay
Other devices and models are available.
Don't be at all concerned if the strength drops below 100%. This could be an indication of an OTT signal strength - it is quality that matters. Feeding an OTT signal is akin to turning up the volume on a hifi beyond that which the system can cope - what happens is the sound gets distorted and so its quality is reduced.
| link to this comment |
Issy: You need to look at what's common to all three sets. If it is a single aerial that is being used then this is the aerial down to the point at which the feed splits.
If the splitter is a powered one (amplifier/booster) then the first suspicion and therefore first thing to rule out must be that it has failed. Do not assume that because the power light is on that it is functioning normally.
Remove the cable from in which comes in from the aerial, remove the cable which feeds one of the rooms and then connect the two. An adapter may be required as the connectors may be the same gender.
Go to the room whose TV feed you have connected to the aerial and see if service has been restored.
| link to this comment |
Brian French: It depends whether it's tuned to Winter Hill for HD services. There are only a handful of ITV HD regions so ones that don't have a HD variant get that of another region. I'm not familiar with which Winter Hill carries.
If it is found to be tuned to Winter Hill then you have what's broadcast. If it's tuned to another transmitter then it needs tuning to Winter Hill instead.
Look at the signal strength screen on ITV HD. It should say UHF channel 54.
| link to this comment |
Brian French: I am in Yorkshire region and get my TV from Emley Moor. I have just checked ITV HD and it is Granada. Therefore it would appear that there is a ITV Granada HD stream and it would seem sensible to assume that Granada's transmitters carried it.
| link to this comment |
Lou Fashioni: No.
I suggest that the reason might be because you have a Group C/D aerial, which is the sort generally installed for Winter Hill. A wideband replacement may be required.
Aerials are designed to pick up (be sensitive) across a particular band/range a frequencies - they aren't interested in whether the signal is analogue or digital. Group C/D is the *top third* of the band of frequencies used for TV.
From Winter Hill the four analogue channels were and the main Freeview channels are still broadcasting on frequencies in the C/D group.
Unfortunately, the new HD multiplex broadcasts on UHF channel 31, which is a Group A channel and therefore in the *bottom third* of the band of frequencies used for TV. And to boot it is on lower power than the rest.
This is the way nowadays - transmitters using a hotch potch of frequencies in different groupings.
Particularly if the aerial serves only one television the booster probably isn't needed for reception of the main Freeview channels. However, it is worth trying it in an effort to receive the lower powered HD services.
On one of the HD receivers, go to the manual tune screen. Select/entry UHF channel 31, select DVB-T2 rather than DVB-T if there is an option and wait to see if it gives an indication of strength/quality. Try turning up the booster if it has such a control and see if the strength on C31 has improved.
| link to this comment |
David Mansell: Then, if your area is "covered", fit an aerial to receive from Emley Moor.
| link to this comment |
George: Perhaps the signal strength is excessive.
See:
Freeview signals: too much of a good thing is bad for you | Digital switchover | ukfree.tv - 11 years of independent, free digital TV advice
A terrain plot it here:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
Whilst it does suggest line-of-sight, it also suggests that objects on the ground may be within the first Fresnel zone (as depicted by the pick line) - look-up Fresnel zone for more information. Anything within that area could potentially affect reception.
| link to this comment |
Tuesday 17 December 2013 3:47PM
G Hinks: This is how it's done these days - a hotch potch of different channel groups. The days of all transmitters carrying channels all in a single one third of the band "group" are long gone.
In around five years time expect channels 49 to 60 to be sold off to the mobile phone network operators. Then Winter Hill's channels will have to move downwards.