Kitz Forum

Broadband Related => ADSL Issues => Topic started by: Weaver on November 28, 2020, 11:39:54 AM

Title: QLN spikes in line #4
Post by: Weaver on November 28, 2020, 11:39:54 AM
Take a look at the picture below showing all the spikes in the QLN for my line #4, compared with the other lines, in which almost all are absent:

How can the pictures be different? The lines run along the same route, with the slight exception of line 2 which is not an EO line, so we believe?

Any idea if these are radio stations or some such and if so what?

The bits per bin graph for line 4 indicates that the spikes above tone 170 donít matter anyway because zero bits are allocated to those higher bins.



Line 4:

(https://i.postimg.cc/4dDMYq4c/B055-F537-E47-E-4619-9-F42-FDEE6-B6205-CC.png)



And for comparison:

Line 1:

(https://i.postimg.cc/FFcWzTMy/D3667-B98-C331-4-BE6-8235-7-AD632272-E3-A.png)



Line 2:

(https://i.postimg.cc/X7CjD6BR/89-C9-DF1-D-BFF0-469-F-81-CC-51151-D51047-F.png)



Line 3:

(https://i.postimg.cc/XJdLzJ3Z/733184-BE-A9-B0-4-BD3-B390-87-A3245-E30-D7.png)



Bits per bin for line 4:

(https://i.postimg.cc/KcHTXbqQ/E0-D94-B7-E-C83-C-4-F11-88-A7-AA03-ABDA3-C45.png)


Title: Re: QLN spikes in line #4
Post by: burakkucat on November 28, 2020, 05:01:17 PM
Take a look at the picture below showing all the spikes in the QLN for my line #4, compared with the other lines, in which almost all are absent:

How can the pictures be different?

It's a mystery. I cannot think of any reason.

Quote
The lines run along the same route, with the slight exception of line 2 which is not an EO line, so we believe?

When I last checked on the status of the four lines, that of number two, which was provisioned with the aid of a pair-divert and originally mentioned PCP10, was no longer associated with that cabinet.

Quote
Any idea if these are radio stations or some such and if so what?

It's very difficult to determine from the plot. Use the raw data, locate the maximum, multiply the sub-carrier index of each maximum by 4.3125 kHz and you will have the frequency for each one. Now visit this site (http://www.mediumwaveradio.com/uk.php) and see if you can find a match.
Title: Re: QLN spikes in line #4
Post by: Weaver on November 28, 2020, 10:08:04 PM
Thank you very much for that link, just what I was looking for.
Title: Re: QLN spikes in line #4
Post by: burakkucat on November 28, 2020, 10:23:34 PM
For reference purposes, here are the five URLs that I have stored under a "Radio" heading --

https://rsgb.org/main/operating/band-plans/
http://www.frequencyfinder.org.uk/
https://tx.mb21.co.uk/
http://www.mediumwaveradio.com/
https://www.short-wave.info/
Title: Re: QLN spikes in line #4
Post by: Weaver on November 29, 2020, 03:23:29 AM
I canít seem to find out what tone 122 is - any suggestions ? I canít seem to find anything listed at around 526.125 kHz.
Title: Re: QLN spikes in line #4
Post by: burakkucat on November 29, 2020, 03:13:34 PM
So the frequency in question is approximately 526 kHz - 527 kHz. That's an odd one. I can't find any potential candidate transmitter.