All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Ricardo: Remove the booster/splitter and connect the feed from the aerial to one of the TVs. Get the aerial working with one TV and then introduce the splitter/booster.
As Crystal Palace is still transmitting analogue services, I suggest that you connect the aerial to an analogue TV and move it around to find out where the signal is the best. Do this for the four analogue channels but not Channel 5 as this is from Croydon and not Crystal Palace.
It is much easier to "see" signals using analogue transmissions than digital ones.
At 2.6 miles you should be aware that you could suffer overloading problems and may therefore need to add attenuation to your aerial system.
Try manually tuning to add the missing multiplexes (don't rescan as this will loose those you've already got):
BBC One=C25
BBC Four=C28
ITV1=C22
BBC One HD=C31
ITV3=C32
Pick TV=C34
Yesterday=C29
Only retune at switchover on 4th and 18th April once you have all the services in your receiver's memory.
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P. Smith: If Hannington's C45 has already been picked up and put in your 800s, then manually tuning to it might do nothing as the receiver already has the channel stored in its memory.
As Crystal Palace (London) uses low frequencies and Hannington uses those higher up, run the automatic tuning scan with the aerial unplugged whilst it's scanning Crystal Palace's channels. Have it unplugged up to 33% should do it (or wait until it gets past C34 if it gives channel number whilst scanning).
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Ken Tibbles: The Digital UK Tradeview predictor suggests three transmitters at your post code. The hilly nature of the area could mean that the area of the post code varies as to what can be picked up and what can't.
Caradon Hill is the first in its list, but it doesn't appear to be the best (based on what Digital UK "thinks").
The PSB are the "Public Service Broadcaster" ones which carry the BBC, ITV1, Channel 4, Channel 5, ITV2, E4, More4, HD services and a few others. The COMs are the Commercial multiplexes which carry the likes of Pick TV, Yesterday and Dave.
The PSBs from Caradon Hill are at 100kW and the COMs are at 50kW. However, whilst the COMs are expected to be "good", the PSBs are "poor" and will get even poorer in April. This is because the COMs from Stockland Hill use the same three channels. That is albeit that Stockland's COMs have negative offsets and Caradon's positive ones.
Stockland Hill is the next transmitter that Tradeview gives a prediction for at your post code. Its PSBs are predicted as "good" and are radiated at 50kW whereas nothing is predicted for its COMs which are at 10kW (at the moment) and they are co-channel with Caradon's PSBs (with opposite offsets). In April, Stockland's COMs are due to increase to 25kW which would explain why the prediction for Caradon's PSBs goes down in April.
Last is Huntshaw Cross which is "good" across the board (except for ArqA which is on low power until next week when it too becomes good).
Again, Huntshaw Cross' COMs are at half power to its PSBs; COMs being 10kW and PSBs 20kW.
Your location is an example of why there are low power COMs services from some transmitters; that is because channels are reused more often and inevitably there are going to be locations where both clash making them unusable or unreliable or at least cause a headache as to where to locate the aerial where the signals from the interfering station are at their lowest whilst still receiving sufficient signals from the desired station.
It's the 18th April when the COMs are due to increase in power from Stockland, so that date may degrade your reception of the PSBs.
Putting in your house number or name into Tradeview may give a more accurate picture for your property.
Looking at the satellite images and Google Streetview, I note that there are trees in the direction Huntshaw Cross for quite a few houses as well as some residing lower down (in the direction away from Huntshaw Cross).
If you decide to go for Freesat, you could retain the current aerial for the Commercial channels that aren't on Freesat.
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Virginia Thorne: Upavon is one of 1000 or so small Public Service only transmitters. The other services are run by the Commercial broadcasters who decide where they wish to place their transmitters. They cover 90% of the population using 80 of the biggest (by population) transmitters. For them to transmit from other transmitter sites, it would roughly double their cost. They declined to increase their coverage.
For a fuller explanation, see here:
Will there ever be more services on the Freeview Light transmitters? | ukfree.tv - independent free digital TV advice
However, I tried an Upavon post code in the Digital UK Tradeview predictor (predicts coverage of transmitters) and there may the possibility that you are on the fringes of Rowridge which is on the Isle of Wight and serves a large area, much of it being on the mainland. It would depend on exactly where you are.
I have spotted one or two aerials on Rowridge in Upavon by looking at Google Streetview. This rather confirms that it might be a possibility to receive from it. Rowridge broadcasts Meridian whereas Upavon relays Mendip which is West region.
It is possible to combine two aerials on different transmitters, however, in this case the channels (frequencies) used by Rowridge and Upavon don't permit this.
However, they are both in the same direction (to within a couple of degrees) from your location and come 18th April the Commercial channels from Rowridge (those that aren't transmitted by Upavon) will be on full power vertically. Before switchover Rowridge's signals were only horizontally polarised, meaning that aerials needed to be horizontal. After switchover it transmits both horizontally and vertically, the Commercial channels being stronger in the latter. As Upavon is vertically polarised, a single vertically polarised aerial may work for both.
In the first instance, you should try manually tuning to UHF channels 25, 22 and 28 on 18th April. These are the three channels of Rowridge's Commercial services and they will come on high power on that date.
I must warn you that there are a few possible stumbling blocks that I can think of:
1. There are some PVRs that don't work too well where they have some channels from one transmitter and some from another. It's therefore not a problem if you don't record the channels.
2. You may need your aerial replacing for one that is sensitive enough to pick-up (or "hear") the weaker Rowridge signals.
3. There may, coming down your aerial lead, be a disparity between the strength of the Upavon signals and the Rowridge ones; the former may be much stronger. The strength of Upavon's signals *may* result in reducted sensitivity of your receiver which in turn makes it more difficult (or problematic) receiving Rowridge's.
This is akin to a bright light with a much dimmer one next to it. The bright light (e.g. a car headlight) makes one's eyes less sensitive to light and hence less sensitive to the already dim light.
As I say, these are possibilities. I would certainly hold out a little hope of more channels come 18th April.
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Tony: According to Ofcom's latest document, on 18th April all three of Hannington's COMs (41,44,47) will go up to their full final power.
Digital UK Tradeview suggests that for Hannington there will be "COM power-up" on 4th and 18th April. However, the power is shown to increase to full level (25kW) for all three on 4th April and not increase on 18th.
I suspect that both of these sources are not entirely correct.
I suggest, as KMJ,Derby has said, that come 4th April, Guildford will relinquish use of channel 44 and therefore Hannington's (ArqA) will go up to full power.
Then two weeks later, when Guildford stops using C41 and C47, Hannington's other two COMs will go on full power.
Obviously, there will be no need for a full retune; just manually tune the multiplexes when they become available, except for poorly designed sets that don't have a manual tune option.
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Val Grace: The Llanelli transmitter, which is to the north of the town on Ty-du Hill, only carries Public Service channels, which is what you've got. This is because the Commercial broadcasters only wish to spend money on transmitting from 80 or so sites nationwide, missing out 1000 or so small sites like Llanelli. For a further explanation, see here:
Will there ever be more services on the Freeview Light transmitters? | ukfree.tv - independent free digital TV advice
In order to get the full service, your aerial will have to point at Kilvey Hill in Swansea. Loft aerials, by their very nature, get less signal than if they were outside, but in some cases that is sufficient. You have found that you get sufficient signal from Llanelli.
However, you may (or may not) be so lucky turning your aerial to Kilvey. Looking at Google Streetview there are quite a few aerials on Kilvey. But the direction to it is inline with the terraces, so a loft aerial is almost certainly out for it due to that fact.
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Pete: Before switchover, the HD multiplex from Crystal Palace is not as powerful as the standard definition services.
HD services are not part of the standard offering before switchover. Crystal Palace was one of only five transmitters nationwide to be selected to carry HD before switchover. It was essentially shoehorned in on the best channel available which is used by Sandy Heath and Reigate which will have resulted in restrictions on how powerful it can be. Perhaps being a loft aerial it's not quite good enough to pick up the lower power HD services.
I wouldn't go replacing the aerial or doing anything costly as not only is it not guaranteed to work, but the current setup will probably work come 18th April.
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Tim: That page states "Supports HDTV/AC3 standard for high definition video and high quality audio experience (DVB-T reception only)", so it only receives standard definition (DVB-T) off-air.
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Briantist: Having looked up "backward compatibility" and "forward compatibility", I agree that I meant to say "forward compatibility".
I believe that the question should have been, "is it not possible for DAB+ services to be forward compatible with current DAB radios?"
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Tuesday 20 March 2012 7:30PM
David Rolles: It's a good idea to confirm that the TV is tuned to the signals from Wenvoe and not Ynysowen or Methyr transmitters.
Ynysowen or Methyr only broadcast Public Service channels, so Commercial ones must be coming from Wenvoe.
Look at the UHF channel it is tuned to on one service from each multiplex. This information is usually given on the signal strength screen.
BBC One is C41 from Wenvoe, C59 from Ynysowen and C25 from Merthyr. ITV1 is C44 from Wenvoe, C55 from Ynysowen and C22 from Merthyr. BBC One HD is C47 from Wenvoe, C62 from Ynysowen and C28 from Merthyr.
Because of the spacing out of the frequencies used by Wenvoe and the other transmitters, it's possible to have the aerial unplugged for parts of the scan to ensure only Wenvoe is picked up.
Have it unplugged up to 30% and then unplug again at 65%.