All posts by Edward Slater
Below are all of Edward Slater's postings, with the most recent are at the bottom of the page.Thanks Chris
Apologies for any confusion - the incorrect information on Nottingham didn't help but it was my mistake. I don't have access to proper test equipment anymore so the data on strength and quality that follows is taken from the television:
Ch Qual Strength
21 10 10
24 10 9
27 10 10
33 9 9
36 5 8
44 8 6
48 1 5
Just to confirm, there is no signal on any channel above 48, as you point out.
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Chris.SE
Thanks again. i have done much of this previously but frustration means I'm happy to re-think it all!
Cable continuity has been checked throughout the whole system and HDMI leads moved well out of the way (previous experience of this particular problem). Flyleads are high-quality, double screened.
The 10-director wideband aerial feeds via the 5G filter (Televes 403210) to an SLX 8-port distribution amp - fixed 11dB gain - and on to the outlets. The main one, with a Panasonic DMRHWT150 PVR to a Panasonic TX40CX680 tv is where the measurements have been taken. The aerial itself is mounted in the loft of a three story house - estimated elevation 75m.
In truth, we need the gain from the amp, so measurements without it are next to meaningless but follow the general pattern as above, albeit at a lower level.
Your comments on the weather conditions are interesting although it's hard to see that this can have been the problem since October when we were getting acceptable signals on Ch48 - the recordings I have are the evidence! The system has been unable to tune to Ch48 since then although, oddly, it has managed to locate the channel on one occasion since we started this communication.
What are your thoughts on adding extra gain in the system?
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Chris.SE
OK - here goes. Measured at the tv with a direct connection to the aerial and all other equipment off. DC loop resistance of the coax run is 12ohms.
Ch qual str
21 8/9 6
24 10 6
27 10 6
33 4/5 5
36 2 3/4
44 1/5 3
48 0 3
(slashes show variation during measurement)
We are 5k from the transmitter with no high land between us. I can see no local changes to buildings or trees etc and no changes within the house/loft. Owing to the age of the property, the aerial is separated from the outside only by a layer of slate roof tiles.
Thanks again
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I agree that the loop resistance looks odd but all the connections seem to be good (using gold plated fittings throughout). It has, however, taken some time to try to check the whole cable length as much of it is inaccessible. Vermin isn't a problem. Whilst it suggests a possible issue, though, the signal reading were taken directly from the aerial. I will continue the investigation.
Interestingly, a small amount of signal on channel 48 has returned but it's not really viable. I'm seeing as much signal on channel 46 despite the aerial being vertically polarised and pointing at right angles to the Sutton transmitter.
Thanks for your help - I will continue to investigate before giving in and paying the cable company.
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After some very helpful input some months ago, I am still struggling to receive a decent (useable) signal on CH48 from the Nottingham transmitter. I had previously answered a number of questions on the strength/quality of the signal on all the Nottingham channels but had run into some issues relating to the status of the feed cable.
I apologise for the delay in getting back to you but this problem is now resolved and the integrity of that feed has been confirmed. I am receiving a reasonable level of signal on CH48 (averaging 8/9) but the signal quality is only 1/2. All other channels are providing perfectly useable signals. Do you have any suggestions as to what I should consider next please?
Loft mounted aerial at 75m elevation, 5km from the transmitter.
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T
Nottingham (Nottinghamshire, England) Full Freeview transmitterFriday 22 July 2022 11:29AM
Nottingham
Chris.SE: Apologies for the delays in getting bach to you - the number of stairs between the aerial and the television always seem a bit daunting!
I have re-run the strength/quality figures as requested with the filter and the amplifier in and out of the system. As far as the simplistic tv measurement capabilities are reporting, the filter makes no difference to the values either with the amp or not.
The amplifier is, however, essential:
Raw aerial figures with amp
CH Str Qual Str Qual
21 2 0 10 10
24 4 4 10 10
27 3 4 10 10
33 2 0 9 10
36 3 1 9 8
48 2 0 5 3
I hope this may shed some light on the possible problems. Thanks again
Ted
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T
Nottingham (Nottinghamshire, England) Full Freeview transmitterSunday 24 July 2022 12:31PM
Nottingham
Chris.SE:
Thanks.
It is clearly a fall-off of signal with increasing frequency but I hadn't considered the aerial as suspect - largely because, as you say, it is well protected and undisturbed. I will however go in and inspect it and the connections.
I estimate it is around 15 years old - probably a Philex or similar as it was bought from Maplins. It has rod reflectors. I will let you know if there is any additional information on it when I get to it.
It is pointing out through a roof that is boarded and slate covered with no felt or insulation (1910 house). There is around a clear metre front and back.
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T
Nottingham (Nottinghamshire, England) Full Freeview transmitterSunday 24 July 2022 1:11PM
Nottingham
Chris.SE:
Well, no point in procrastinating. I've just been to look at the aerial and I can see nothing physically wrong with it on a visual inspection. I have photos of the aerial and of the connection box but can't see a way of sharing them with you here. The cable termination looks solid and clean as expected.
There are no obvious maker's marks on it so I can't help any further on that score. In case I have misled you, there are 10 'X' shaped directors, a short solid stub and a two loop dipole. There are 4 reflector rods each side.
If there are any other basic checks I can make on it, please let me know. It certainly doesn't look as though it needs replacing!
Ted
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T
Nottingham (Nottinghamshire, England) Full Freeview transmitterMonday 25 July 2022 9:38AM
Nottingham
Chris.SE:
Yes, that is the same basic aerial - the version I have, because of its age, doesn't have the inbuilt 4G filter. The one I'm using was supplied by the project (Televes 404401).
I have checked all the connections. The cable terminates on a balun pcb which is capacitively coupled (through the pcb varnish layer) to the dipole. The cable from the aerial to the splitter is only two metres long so, although I have checked end to end continuity, the loop resistance is well below my measuring capacity.
Whilst up there I also checked the aerial alignment both vertically and horizontally to verify that it is pointing to the Nottingham relay, based on the published latitude and longitude.
You can see why I'm getting exasperated.
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Page 1
Friday 14 January 2022 12:55PM
Nottingham
We have been receiving excellent signal on all mpxs from the Nottingham transmitter for a number of years. Since around the end of Oct 2021, we have lost virtually all signal on channel 48 - I have recordings of programmes in October to prove it worked! I have followed all the recommended reset procedures and checked the aerial (loft mounted), amplifiers and cables (I am a qualified electronics engineer) to no avail. Signals on channels 38 and 50 are at strength 10 and there is a 5G filter installed (I have tried without it). Any ideas?