All posts by Steve Donaldson
Below are all of Steve Donaldson's postings, with the most recent are at the bottom of the page.
John Dennis: This full list of Freeview programme channels is here:
Channel listings for Industry Professionals | Freeview
This indicates which multiplex (mux) each is carried on. The six main multiplexes are:
PSB1 = BBC A (BBC standard definition TV and BBC radio)
PSB2 = D3&4 (ITV1, Channel 4, Channel 5 and others)
PSB3 = BBC B (all HD channels)
COM4 = SDN
COM5 = Arq A
COM6 = Arq B
How is COM4 reception? Is the quality down on this channel? What about the three PSB channels?
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Rai: The Freeview predictor gives glowing '100' scores across the board for all six main multiplexes and the local multiplex from Black Hill at your postcode, suggesting excellent (the best) reception. I think this may be over-egging the pudding somewhat.
The ground level at properties in your postcode is around 15m give or take a few metres. 200m or so to the east, in the direction of the transmitter, the ground is 20m or more higher on which there is the school, church and several apartment blocks.
The higher ground can be seen on this heat terrain map:
https://en-gb.topographic-map.com/map-cgt/United-Kingdom/?center=55.85278%2C-4.35936&zoom=16
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Mr. A. Phillips: This website is not affiliated with any of the broadcasting companies. It is entirely independent.
Freeview lists transmitter engineering works on this page which you might like to bookmark for future reference:
Planned engineering works | Freeview
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Don Pedley: In addition to the points made by Chris.SE, the Findon transmitter got a big power boost at digital switchover (DSO) in 2012. It is possible that in some situations a booster was fitted in the days of analogue (prior to DSO) and that post-DSO it is not required and could potentially result in too high a signal level.
If the booster is on the roof then any 5G filter must be fitted before it. That is, the cable comes out the aerial, into the filter, out the filter and into the booster. Restore TV should send a technician out free of charge to fit the filter on the roof. As part of the job, he will check the signal levels and, if necessary, remove the booster. Thus, such a scenario is a way of getting the booster removed by a technician for no charge.
If the booster is to allow the signal to be fed to more than one room then that will change things in terms of having it removed. The same still applies as to the filter going before it, and if it is on the roof then Restore TV should send someone to fit it at their expense.
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Richard Holloway: There are ongoing engineering works at the Wrekin transmitter, according to Freeview. It is possible that this could be the reason for the issue arising.
In terms of what you can do then try a manual scan of UHF channel 47. This is the broadcast channel used by the Wrekin for the programme channels you have cited.
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Charles Hussey: SSEN reported a power outage at the transmitter site, reference NY0093. This was shown on SSEN's map ten minutes or so ago, although now I have refreshed it is no long visible, so I assume power is back on again. The power cut was reported at 09:29 today and there is/was an aim to restore power by 16:00 today.
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Chris.SE: I wonder if the time given by the BBC is an hour behind, it still on GMT.
The reason I say this is because the time the BBC say the transmitter went off was 59 minutes before the power cut was said to have begun. This might actually be 1 hour difference, the seconds not being the same for both clocks.
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Marton Hayes: It is no longer available on the Wolverhampton & Shropshire DAB multiplex. See Ofcom's Radio Broadcast Update for April 2024:
Radio broadcast update April 2024 - Ofcom
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Richie Smith: The aerial you have referred to is omnidirectional. It claims to have a gain of 3dBi and says this is "high gain". I don't think so.
What is more, the TV transmitter you are looking to receive is Redruth which is horizontally polarised. You would have to mount the aerial horizontally, as in on its side, for best effect.
A directional aerial has "gain" in one direction, the direction which it is most sensitive. This is at the expense of increased "loss" (less sensitivity) in other directions. It's like fitting a reflector behind a bulb to give a "gain" of light in front of it.
The TV signals are all coming from the same direction, from the same transmitter site, and as such the most effective aerial must be one that is directional.
An assessment needs to be made of where the aerial is to be sited. The best situation is at a window or wall which faces the transmitter. A clearer view the better.
As far as using an aerial that isn't a set-top one then I don't think you will better the Blake BLA-LP20K referred to by Chris.SE. It is compact at just 45cm long, and it is also designed for UHF channels 21 to 48. Channels 49 upwards formerly used for TV have been cleared and given over to the mobile phone operators. There is little point in buying a TV aerial that is designed to pick up these channels.
In terms of indoor 'set-top' aerials, the 'Silver Sensor' is a good design:
https://antiference.co.uk/product/silver-sensor-indoor-uhf-antenna/
There are no guarantees of reception, especially with indoor aerials. How good it will is dependant on the location.
If you do go down this route then you may need to move the aerial around to find the best spot. But if the TV isn't tuned then you have two unknowns. You can't tune to something that isn't there. For this reason you should use manual tuning on the channels used by Redruth.
Another point to be aware of is that the Caradon Hill transmitter is on a bearing just 7degrees away from Redruth, but further away. You need to make sure your TV is tuned to Redruth and not Caradon Hill. This is because pointing the aerial in the general direction of Redruth is to point it in the general direction of Caradon Hill as well. Of the two, I would expect Redruth to give better reception at your location.
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Friday 10 May 2024 11:56PM
Paul Homer: None of the BBC Three Counties Radio FM broadcasts are good along that stretch of the M25.
If you manage to receive it all the way along the M40 to the junction with the M25, then I guess you must be tuned to High Wycombe on 98.0. You may be able to pick it up on 92.1 from Hemel Hempstead (Pimlico) from around junction 18 in the Micklefield Green area, or perhaps sooner. The six or so miles in-between these two points is where reception is most difficult.
RDS Alternative Frequency (AF) can be useful in keeping tuned to a station having moved from an area where it is on one frequency to where it is on another. However, it only works where the alternative signal to be switched to is strong enough for the radio to be able to decode the RDS. In this instance, you are looking to receive the station outside the area where the signal is strong enough to offer RDS on any of its frequencies.
Thus, when driving clockwise from the M40 towards the junction with the M1, for example, the radio will not switch to 92.1 until the signal gets strong enough for it to decode the RDS data, which will probably be after the point at which the signal can first be received. Thus, you may have to manually tune between the frequencies, perhaps having stored each under a different preset. Depending on how the radio works with respect to AF will depend on how easy this is -- different radios work differently.
With some radios, AF cannot be turned off, and this can be a nuisance. In other cases it can be set as on or off per preset, or on or off for all presets together (in the settings menu). If it's possible to turn it on/off per preset then this is the easiest to work with: store the frequencies under different presets with AF off. Then change as you move, working out where each is best.
Coverage maps by transmitter/frequency for FM stations are here:
http://a-bc.co.uk/mca-measured-coverage-area-maps/
The coloured area shows where the signal level is projected to be at or above a predefined level. This isn't to say the broadcast can't be received outside that area. But as you can see, the coloured area for 92.1 begins around Micklefield Green. The question is, how far before that point can it be picked up well enough to listen to, without too much hiss and intermittent fading?
Judging by coverage maps I guess that 103.8 might be the one to try first along that length of the M25. Much of the motorway there runs north/south and the transmitter is roughly due north, so in line with the road which runs in a cutting along some of its length.