All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
Brian Richardson:
The aerial may be a wideband then (black plugs in the boom - but black has known to be used in Grouped aerials!), but even so, the gain of all these aerials drop off on the lower channels only log periodics have a flattish response.
It does seem that all your coax is OK - good news, and the signals strengths seem pretty consistent and although there's a bit of variation in the errors, it's the same multiplexes.
Is the amp gain currently up full? If so, out of curiosity turn it down a little bit and see what is happening to the strength and errors on all the multiplexes. Likewise if it's not up full, turn it up a bit and see what happens - note all the figures.
One of the reasons I suggested coupling the aerial direct to your main TV coax to check the figures, is that too much signal can also produce problems. Gain figures can appear to go down and errors ultimately increase.
As your booster/spiltter has variable gain, the results from changing the setting are going to be interesting.
There's some info about 'tropo' in posts I made a few weeks ago that'll be worth repeating.
Despite the incorrect spelling, this link does work - simple technical explanation
https://www.bbc.co.uk/rec….jpg
Do remember they are all general propagation predictions and it doesn't mean that one WILL be affected, sometimes just bands II & III may be affected and not IV & V, sometimes the other way around, sometime all or none! The predicted areas don't necessarily need to be directly overhead, they can be immediately adjacent.
Tropospheric Ducting Forecast for VHF & UHF Radio & TV is one of the ones I refer to,
also Europe | Tropospheric Propagation Forecast
It's worth keeping an eye on Problems with Freeview reception? | Help receiving TV and radio as the BBC sometimes put a Works and Warnings note up (there's been one but it will usually disappear when conditions change).
I do look at Updates and alerts | Freeview for other things but they're often unreliable for this sort of thing (always after the event, so to speak, as with some other things they put there!).
But one of the main indicators as to whether you are suffering interference at a given time, is the error figures (assuming that they are zero or constant and very low when there's no tropo).
Current conditions may ease on Wednesday but could return again towards the weekend!
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Paul Heywood:
Your intermittent and current loss is most likely due to current weather conditions. Unfortunately temperature inversion/tropospheric ducting is accompanying the high pressure weather system causing signals from distant transmitters in Europe or the UK to affect reception of wanted signals. COM7 can be more vulnerable than some multiplexes due to operating as an SFN and at lower power than most of the other multiplexes, but it is very much depends on location. Freeview and the BBC have current warning about potential intermittent disruption to reception.
Do NOT retune, when correctly tuned, all this is likely to do is clear your current tuning if no signal is found at that time.
To compound matters there is Planned Engineering currently listed for Sutton Coldfield which may affect signals.
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Michael Brown:
As mentioned in the post before yours, there are no faults or Planned Engineering currently listed for Waltham and IIRC the last time any were listed it was 2 weeks before Christmas.
Unfortunately reception is very variable across your postcode and it's not one of the best places for Freeview reception according to the predictors.
The post before your also details the current problem.
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m Flinders:
LCN 49 - (currently) Great! tv is carried on Local multiplexes where there's a Local station on LCN7 or 8, and these are only broadcast from a limited number of main transmitters and the signal is generally beamed towards the urban areas of population they were setup to serve. A number of Great! channels were moved to Local multiplexes by their previous owner Sony back in July 2019.
See Channel listings for Industry Professionals | Freeview for which channels are carried on which multiplexes.
There's no Local or COM7 muxes at Heathfield.
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Ben P:
In addition to StevensOnln1 information, to compound matters, Emley Moor is currently listed for Planned Engineering which may affect signals.
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Gary Szreider:
This independent helpsite is saying that the transmitter has no problems because there've been no automatic updates available for some reason, however having done some checks I can find no faults listed for the transmitter and it's not listed for Planned Engineering.
Your signal loss is most likely due to current weather conditions. Unfortunately temperature inversion/tropospheric ducting is accompanying the high pressure weather system causing signals from distant transmitters in Europe or the UK to affect reception of wanted signals. It can vary by the second, minute, hour or longer as well as being possibly intermittent.
Freeview and the BBC have current warning about potential intermittent disruption to reception.
The conditions may ease on Wednesday but may return towards the weekend.
Do NOT retune, when correctly tuned, all this is likely to do is clear your current tuning if no signal is found at that time.
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Alan Goss:
Hi Alan. Depending on where you are within your postocde, there are 3 possible transmitters. First question, which way are your aerial rods (or squashed Xs) horizontal or vertical?
Are you getting the full range of muxes including COMs4-6, or just the PSBs?
Hastings requires vertical and is not the best across the postcode, there's a small UHF Relay at Bexhill (horizontal) which should have the most reliable reception but it's only the 3 PSB muxes, and Heathfield (horizontal as I'm sure you know) is not so good at the low end numbers (down to 26) but better as you go up.
But, remember predictions aren't always 100% accurate, does what you see with the aerials tie in?
The "sharpness" of the pictures should not depend on the transmitter unless that relay is not up to scratch!
Transmitter detail -
Bexhill, bearing 91 degrees, almost due E, horizontal polarisation - PSBs1-3, UHF C33, C36, C48.
Hastings, bearing 74 degrees, slightly E of ENE, vertical polarisation - PSBs1-3, COMs4-6, UHF C25, C28, C22, C23, C26, C30
Heathfield, bearing 313 degrees, almost NE, horizontal, PSBs1-3, COMs 4-6, UHF C41, C44, C47, C40, C43, C46
If you are getting reliable signals from Hastings, you might actually be better off with it being vertical polarisation as there's quite a bit of tropo around at present and it may just suffer less from any interference.
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Edward Slater:
Hi. This is certainly a bit odd. Process of elimination seems the best way to proceed, shouldn't need any specialist equipment (hopefully!). Those Signal and Quality figures from the TV are useful.
In your o/p you mentioned signal strengths 10, leaving aside your error with the channel numbers, I assume that they were those higher channels. Those strength and quality figures now show a definite drop with the increase in channel number.
I should perhaps mention that there has been some temperature inversion/tropospheric ducting around which should have now cleared (although some predictions show it n#might return on Friday). Have those strength and quality figures changed since you took them?
That said, it's unusual for such interference to affect several channels in that way, normally it would be an individual channel (or two).
How have you got your equipment interconnected? You mention recordings, so I assume you've got a PVR of some sort connected to the TV. Have you altered anything around, moved any cables etc.?
Two things to check - make sure you haven't got any HDMI cables close to the aerial cable or flyleads as HDMI has been known to cause interference (especially when the coax isn't high quality double screened eg. CT100 or similar). Carefully check any flyleads, they can go intermittent especially the connection at the back of the plug if they are pre-made moulded types.
You mention a 5G filter and an amplifier. Is the amp a distribution amp/splitter or a "masthead type"? Does it have variable gain?
What could be useful is seeing what the strength and quality figures are for each multiplex with the aerial coupled direct to the coax direct to the TV, bypassing any filter. amp, splitter and PVR etc. Then try the same with the filter in place.
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Tuesday 18 January 2022 12:34AM
Nick Richards:
You are not in the best of locations for COM7 reception unfortunately. It's predicted to be potentially variable but otherwise good when not subject to any interference conditions which is what is currently the problem.
Your intermittent loss is most likely due to current weather conditions. Unfortunately temperature inversion/tropospheric ducting is accompanying the high pressure weather system causing signals from distant transmitters in Europe or the UK to affect reception of wanted signals. COM7 can be more vulnerable than some multiplexes due to operating as an SFN and at lower power than most of the other multiplexes, but it is very much depends on location. Freeview and the BBC have current warning about potential intermittent disruption to reception.
Do NOT retune, when correctly tuned, all this is likely to do is clear your current tuning if no signal is found at that time.
There are no faults or Planned Engineering currently listed for Mendip.