menuMENU    UK Free TV logo Archive (2002-)

 

 

Click to see updates

All posts by Edward Slater

Below are all of Edward Slater's postings, with the most recent are at the bottom of the page.

E
Full technical details of Freeview
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?

link to this comment
GB
E
Full technical details of Freeview
Wednesday 19 January 2022 10:19AM
Nottingham

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.

link to this comment
GB
E
Full technical details of Freeview
Thursday 20 January 2022 1:09PM
Nottingham

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?

link to this comment
GB
E
Full technical details of Freeview
Friday 21 January 2022 12:34PM
Nottingham

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

link to this comment
GB
E
Full technical details of Freeview
Friday 4 February 2022 11:47AM
Nottingham

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.

link to this comment
GB