All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
Hello Roy: You said you are currently using your old contract aerial outside, I take it looks something like https://www.aerialsandtv.….jpg and if it's always been pointed at Sutton Coldfield (& I hope still is - not moved in the wind) then I'd guess it was a Group B (got/had a yellow bung in the end) I'd also hope post 1995 and hopefully just got sufficient gain at it's top end for UHF 55&56. Do you have the two 4G filters in circuit at present, if so try taking one of them out and see how it affects performance/signal on 55&56.
I don't think I ever asked, are you using any amplification and/or distribution/splitters at all?
So why is it a "difficult" area - I don't know about rare, uncommon certainly but this won't be the only example, not really poorly understood - the reasons are known, difficult to treat ...... definitely. The reasons are that signals are reaching your area from 4 different transmitters (that doesn't mean they are all useable). Sutton Coldfield obviously but also Bilsdale, and much weaker Emley Moor and Sandy Heath & that's ignoring others that may come and go when there's a lift on (propagation). There's also that local transmitter that may be causing some very strong input to your TV's front end if you are close enough to it.
The way of cutting down on the unwanted signals is a highly direction aerial but here comes the difficulty, it needs very low side lobes, good cross-polarisation rejection, and a damned good front to back ratio, as well as good gain at 55 &56. The aerial that could have fitted that bill would have been a Log40 with the help of some masthead amplification, but these log40s have not been available in recent times. The "replacement" is the log36 but because of the in-built 4G filtering it's response at 55&56 drops off and it might just not have enough gain when the 55&56 signals aren't very strong.
The trouble with many of the other "highly" directional aerials is they can have some horrible side-lobes and not always good front to back ratios. A compromise might be a well made Yagi, a Group K looking like a better option from the gain & frequency response point of view but then again it may not be any better at not receiving the signals you don't want.
Do you know exactly what model your Group T aerial is? It might be ok (in the loft) with some amplification, but getting some idea of it's performance would be helpful.
Do you still have that Labgear LAB450T? Whilst it maybe a bacofoil aerial that doesn't matter in a loft. As well as trying tweaking the position of your group T, I think the 450T might be worth another try for comparison if nothing else.
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Roy:
A correction to my previous post - it was late and I didn't have the checker open at the time I posted :o
I meant Belmont not Bilsdale (getting my B's mixed up - there's been retunes at Bilsdale recently) and I forgot about Waltham that can also come in quite strongly.
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KarlR:
If your provide a full postcode we can look at the predicted reception. Freeview's advice isn't always the most helpful unfortunately, however, if another aerial was needed then it is the landlord's responsibility.
Which 13 channels are you getting?
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KarlR:
For your postcode you shouldn't have any problem getting all the available multiplexes from Pontop Pike. I'd also be surprised that considering you're only about 18km from the mast that you wouldn't get most, if not all the multiplexes even on quite an old C/D group aerial.
The issue might be that you can in fact receive several transmitters at your location, and in particular the Fenham transmitter which is only 6km away BUT is much lower power, doesn't have COMs 7&8 and requires an aerial that's vertical polarised. A lot of aerials aren't that good at rejecting cross-polarisation signals that are moderately close.
It depends on how your set is tuning, because the Fenham UHF channels are lower in the band than Pontop Pike, so it is likely it will find these before Pontop Pike's channels so you may well find Pontop Pike's in the 800's in your programme lists.
The "trick" here will be to do a manual tune, but do it as follows. Unplug the aerial and do a full automatic tune. This should clear memory of all previous tuning as no channels will be found.
Plug the aerial back in, and in your Tuning section, find the Manual Tuning option.
Tune the following UHF channels for Pontop Pike - 39, 42, 32, 34, 35 for the SD channels, if you have HD 45, 55, 56.
Let us know how you get on.
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C
Sutton Coldfield (Birmingham, England) Full Freeview transmitteSunday 17 November 2019 7:05PM
Derby
Roy:
I presume you want Sutton Coldfield because you'd prefer Central West rather than East from Waltham?
Taking a "virtual" stroll around the area, it seems relatively flat, but some ground seems to be about 10m higher than others. But even in absolutely flat areas, the predictor was giving very variable results from one adjacent road to another !! I don't know if you happen to be at one of the slightly higher points.
Try taking that Ch.59 filter out and see what difference it makes to anything. Is it the same make/quality as the Ch.60 one?
For some stupid reason I was thinking your group T aerial was a different one from the LAB450T ! Did you try the LAB450T with your amplifier or without it and with or without filters?
As I think you probably know, RF and aerials can be a bit of a black art. I think it's a case of try this, try that, try a different position, even slightly off bearing, but my primary concern would be that Ch.59 filter, too close to 55/56 for my liking.
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John Jenkins:
The simple answer is they are not getting them from Bincombe Hill as it's a Freeview Light transmitter which doesn't transmit the multiplexes that those channels are on, it only transmits the 3 PSB multiplexes. For which channels are on which multiplex, see Channel listings | Freeview
So as they are getting them from another transmitter, we'll need your friend's full postcode and yours to look at the predicted reception at your locations to see which transmitters and multiplexes may be receivable.
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KarlR:
Oh dear. I had heard that about Youview boxes, not familiar with them. I'd complain to your service provider that a frimware update is needed to allow this.
Are you finding any channels (LCNs) in the 800's? Does the box have a program manager that would allow you to move/renumber them?
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Ian Carrick:
Yes those transponders would be out of date as the first numbers appear to be the UHF Channel in kHz.
What the V,6900 mean I've no idea, nor have I any idea how to edit the entries.
The numbers you want for each are as follows -
618000, 642000, 666000, 562000, 578000, 586000, 746000, 754000, 570000
Those are in the order PSBs 1-3, COMs 4-8, Local.
I don't know if this DVBLink requires them in increasing number value of if that order will do.
FYI, the UHF channels in the same order are 39, 42, 45, 32, 34, 35, 55, 56, 33.
I assume you know of the website dvblogic.com - Tvmosaic player/">dvblogic.com - Player but on the homepage dvblogic.com - Tvmosaic they say it's being replaced. Also found this DvbLink TV Server, Version 6, on Synology NAS - YouTube don't know if it'll help with any setup, didn't watch more than a few seconds.
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Saturday 16 November 2019 2:28PM
Roy:
An "interesting" area for Freeview reception is all I'll say to start !!
Just also to clear up any possible misunderstanding there maybe about SFNs from what you've said, they are not like old AM radio transmissions, nor are they analogue transmissions being repurposed. But you are correct in the remark about problems in fringe/overlap areas from two or more transmitters - that's the bit that could be thought of a similar to old AM transmissions, but this is supposedly minimised by the signals being "synchronised"! As far as equipment goes, it is (we think) the digital but pre-dso equipment being used in SOME instances to provide the COM78 transmissions. Not all that equipment was capable of being tuned to the new SFN channels (so some transmitters have lost them) and a lot of it has power limitations as well (we believe). So unless someone from Arqiva can educate us as to the exact facts, that's what we think from the gleanings we've made from the limited information available.
LCN113 is RT HD, I only asked because if you are getting it, you are getting COM7! QVC HD is on COM8.
I'll come back and post a bit about aerials later as right now I must get on with some things here.