Full Freeview on the Bilsdale (North Yorkshire, England) transmitter

_{sentiment_very_satisfied}Platinum

1:56 PM

Alan: Different receivers have differing tollerances and therefore I wouldn't jump to the conclusion that there is a fault.

The thing to be aware of about is that aerials may require replacement because some are out of the former group.

In the days of four- analogue, each used four UHF channels (frequencies) from within the same "group". Each group is a portion of the band of frequencies used for TV.

Aerials that were installed were usually grouped meaning that they are most sensitive of one particular group and that they drop off in sensitivity outside of the group.

Bilsdale was Group A ( to ) for all five analogue channels and all pre- digital multiplexes, except for one (Mux D which carried , etc). Group A is the bottom third of the band.

Post-switchover the Public Service (PSB) channels are on Group A channels, but the three Commercial (COM) channels are in Group B (middle third of the band). COM5 is the highest of the COMs which is on .

The channels are (those in brackets are the pre-switchover channels of the equivalent multiplexes):

PSB1 | BBC One | ()
PSB2 | ITV1 | (C21)
PSB3 | | (n/a)
COM4 | | ()
COM5 | Pick TV | C46 ()
COM6 | Film4 | ()

Prior to switchover the may have been needed because the digital signals were on much lower . It is, of course, always worth a try without it. But I wonder if it may in practice be being used now to compensate for the weaker signals due to them being out of group.

To understand the sensitivities of aerials, see these example curves:

Gain (curves), Again

If, having tried removing the booster, it doesn't work and you decide to replace the I suggest that you get a Group K aerial if you get a yagi type or if it's a log periodic, then these are but have a flatter response than yagis (see gain curves on above link).

See here for some pointers:

Bilsdale TV Transmitter

Jan
7:28 PM

Please me I live in and have always recieved my from after the on the 26th I have now lost like 5+1 5* challange and im gutted why is this why have they gone i have retuned 3 times since and its still not there!!!! help

Jan's 4 posts

_{sentiment_very_satisfied}Platinum

7:41 PM

Jan: Try manually tuning for them. 5+1, , 5* and are carried on COM4 which is on UHF 43 from and and are on COM5 which are on .

Perhaps you need your replacing to receive the COM channels. I covered this in response to Alan in the posting immediately before yours.

Matt
10:03 PM

I live in Pickering, and have had an acceptable on all until the . Now PSB1 experineces freezing and breakup. I am using a digital and a 4 way . I believe this is caused by too strong a signal from BBCA, so I have reduced the on the booster. However, the signal is not at all maxing out, (strength 8 7.) If anyone can with this please. I am using a Thomspon top up tv box

Matt's 3 posts

Friday, 28 September 2012

_{sentiment_very_satisfied}Platinum

11:21 AM

Matt: Have you confirmed that it is not picking up 's BBCA on instead of 's which is on ?

_{sentiment_very_satisfied}Platinum

11:36 AM

Could someone suggest why it might be that the DUK Postcode Checker "thinks" that the PSBs aren't as good as the COMs in the Saltburn-by-the-Sea area?

There appears to be no co- transmitters that could degrade and the COMs are on half- to the PSBs. So surely the COMs would be most likely to be not as good as the PSBs, if any.

Postcode Checker - Detailed View

Postcode Checker - Detailed View

Up the coast at , all are "good", but the figures for served and marginal are slightly down for the PSBs:

Postcode Checker - Detailed View

I appreciate that the DUK is a calculation and therefore there may be variables that aren't totally correct. But what could make the predictor give this result. Could it be ?

Tony
1:20 PM
Darlington

First off, just wanted to say what an excellent site this is, and it's been very informative.

I'm p'd off right now, as I don't think there's been any publicity given to the change of frequencies on post-cutover - so for people such as my parents, who had a decent on all but Mux6 pre-cutover - suddenly find they've got fewer than before, and are unexpectedly having to think about having the replaced.

So, with that in mind, looking at the frequencies table above I see that the current aerial group recommended for bilsdale is K, but for 2013 onwards it says W. Is there yet another change coming next year?

Is a K still the recommended type, or should they be looking at a W type?

Thanks.

Tony's 2 posts

_{sentiment_very_satisfied}Platinum

2:59 PM

Tony: My sympathies go to you.

Before replacing the , try manually tuning if the allows.

There are also a proportion who receive from PSB-only relays, such as in and , who have had to wait to to get any Freeview at all. These people will be disappointed that they have limited .

The nonsense of so many or semi-wideband transmitters (where PSBs are in one group and COMs in another) is caused by the fact that channels 31 to 37 have been ringfenced to be sold off for more multiplexes... or maybe not depending on what the powers that be decide.

Consequently, where previously Group A channels available were 21 to 35 (or perhaps you could say 21 to 37) are now 21 to 30 (but only a handful of transmitters use ).

At the top end (C/D), to have been ringfenced to be sold off to 4G mobile operators, so this is now a smaller group as well.

The silly nonsense of prospectively putting three new muliplexes in the 31 to 37 gap means that some Group C/D aerials (on C/D transmitters) may have to be replaced.

When it was all planned out, the vast majority of transmitters had four in the same group. Queue the introduction of in 1997 and the insistence that logical planning and universal coverage should go out the window in order to cram in as many as possible.

The objective has always been that post-switchover the PSB are available in all areas that four-channel analogue was, and without the need to change aerials. This has been achieved in all but a small number of cases.

In answer to your question, in areas where a log periodic will work, use one. These are naturally wideband and have a much flatter response than yagis.

Where more is needed, a yagi must be used. Because the gain curve of yagis always peak at a relatively high channel and slope off downwards, wideband yagis have less gain on Group A channels. This means that a "high-gain" wideband aerial isn't "high-gain" on Group A channels:

Aerials, TV Aerial and Digital Aerial

See this page for some examples to understand this point:

Gain (curves), Again

It is a compromise. The more channels you design the aerial to operate across, the more the curve stretches and hence the more the low gain end spans more channels.

I'm not sure on what basis that the above says wideband. Perhaps because everything may all get thrown up in the air and it will be anyone's guess as to where they land....

However, on the basis that useable C/D is now smaller, I wouldn't have thought that they would be allocating any C/D channels to transmitters that currently don't have them.

In any case, it doesn't mean that "no" signal is received out of group. As I say, the gain slopes away.

For more information and products, see ATV's site:

Bilsdale TV Transmitter

Tony
3:39 PM
Darlington

Many thanks for your quick response.
I had tried manually retuning, but that didn't make any difference.
I've read through the aerials links, and as you've suggested a log periodic sounds like the best option. Cheers!