KDL-32WE613 digital signal checker - what is the C/N number?.

[OLD-MIKE]

Please Help, I have been have problems with receiving channels via a roof aerial. On using the digital signal checker, it shows the TV channel number, the MUX number which are constant, and a varying C/N number. It also shows the Signal Level and the Signal Quality.  The Signal Level can be 100%, but the Signal Quality appears to correlated to the varying C/N number. On the ITV MUX channel I watched the Signal Quality vary from 100% down to 1% with C/N starting at 40 and falling to 14.

On the BBC Mux channel the Signal Quality was 40% and went to 100%, with C/N varying from 17 to 30.

The problem can be on any of the MUX bands, at any time, or in any weather condition. I can receive all channels sometimes with 100% Signal Level and Quality. Thank You.

[Elodin]

Heyyy, The C/N number is short for Carrier to Noise ratio, I would recommend you to connect the aerial directly to the TV and check if it's more stable. You can also check if the TV is running on the latest software version: https://bit.ly/3AyYYnv , and you can reset your TV to factory settings as well: https://bit.ly/3nM5CiB. I hope that helps you, let me know the outcome.

Cheers. 

[OLD-MIKE]

Hi, thank you for the info, and recommendations. I will let you know the outcome when I have completed the tasks.

Thanks

[OLD-MIKE]

Thank you for the info on my C/N number query. I have 2 TVs and 1 hard disk recorder on my aerial system using a 4 way aerial amplifier, which was professionally installed with the roof aerial hard wired into a multiway aerial terminal box in the roof loft. Each of the units on the aerial having a single digital tuner. I have checked the software update, and all units are on automatic update (ON) The problem is experienced on all units, and I have also had a word with my neighbor, who told me she had been having problems with receiving Freeview from her roof aerial since the start of Covid lockdown, and in the end she had enough, and purchased a Now TV stick, and streams her TV over the internet. I have raised a case with the 'BBC Reception Service' and they have come back to suggest it could be interference, and have requested that I attempt to log the instances, and check for causes in my property. Thanks once again for your valued help with the C/N number, which allowed me to pass this information onto the BBC to get the ball rolling.

[daveyh64]

As you have reported your signal strength can be as high as 100%, this may sound good but

often is not as this can overload the TVs or recorders tuners causing interference such as pixellation and drop outs.

As you have said your aerial has an amplifier attached, do you know if you can adjust the amplifier to reduce the signal strength. If not you may have to buy an attenuator (variable one) so you can reduce the signal strength getting to your devices. Attenuators are inexpensive and can be bought online, simply plug the aerial cable in 

to the attenuator and attach another cable which goes to your devices. With the TV or recorders set to show you

the signal strength you then use the adjustor/ potentiometer on the attenuator to lower the signal strength to

about 90%. The most important one is signal quality, 100% there is good.

You may want to read more here, https://www.smartaerials.co.uk/blog/what-is-the-difference-between-tv-signal-strength-quality

[OLD-MIKE]

Thank you for the link to the info on TV signal check data. This morning I did another signal check on my Sony smart TV 2017, my old 2009 Sony lcd TV, and a 2009 Sony hard disk recorder. I used the same TV channels BBC1 (1) MUX 27, ITV (3) MUX 24, Drama (20) MUX 33, Sky Arts (11) MUX 36 and Sewing Street (73) MUX 48.

On the smart TV all the channels were o.k. with a little activity on the Pre Vit. E-04, there was no Post vit. error. Signal Level and Quality 100% 

On the old Sony TV  All MUX channels were o.k. apart from MUX 33 (Not Tuned). The channels that were working all had Pre Vit in the E-04 range, and no Post Vit. errors, with 'HIGH' signal level. 5 minutes later I checked MUX 33, 'NO SIGNAL', but the Pre Vit. error was E-02, as was the Post Vit. error. I checked MUX 33 again after 5 minutes, and MUX 33 was back on with Pre Vit. E-03, no Post Vit. error, Signal 'HIGH'.

On the Sony hard disk recorder - the Signal Checker gave different info. All channels were working o.k. with a Signal Quality of 100%, but the Signal Strength varied between MUX 33 87% and the other MUXs at 94/95%.

In reading the article on Signal info, It states that the Signal Level/Strength is not very accurate, and that Signal Quality is the most important, so maybe the aerial amplifier is o.k. The aerial system was upgraded in 2009, and we have had no problem until early 2020, and then it appeared to be on MUX 33, 36 and 48, but only occasionally, but since the Spring this year it has effected MUX 24 and 27 as well, sometimes loosing BBC for long periods.