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[Tim69]

Not got a Sky receiver you could pinch one from?

[burakkucat]

Not got a Sky receiver you could pinch one from?

b*cat lifts a paw, exposes the claws, dismisses any suggestion of objects related to the Murdoch empire, yawns and thinks "feed me"! 

[Tim69]

Not got a Sky receiver you could pinch one from?

b*cat lifts a paw, exposes the claws, dismisses any suggestion of objects related to the Murdoch empire, yawns and thinks "feed me"! 

 
 So sorry, only a suggestion

[NewtronStar]

After a lot of "fiddle-faddling" and "cat cursing", three sets of measurements were made with a 398 metre "local loop".

will the 398 meters LL pick up any interference from it being coiled like that ? 

[burakkucat]

So sorry, only a suggestion

I appreciate it. 

[burakkucat]

will the 398 meters LL pick up any interference from it being coiled like that ? 

It's not so much the "pick up" of RFI but the effect of the attenuation, from a significant loop length, in which les-70 is interested.

As for the length of the loop, once the two RJ11 to 431A patch leads are also factored in, it will be a very nice round 400 metres.  

[NewtronStar]

will the 398 meters LL pick up any interference from it being coiled like that ? 

It's not so much the "pick up" of RFI but the effect of the attenuation, from a significant loop length, in which les-70 is interested.

As for the length of the loop, once the two RJ11 to 431A patch leads are also factored in, it will be a very nice round 400 metres.

I know it's just for the attenuation test, but looking forward to see your results but I am sure it will be Technical jargon until someone can break it down into layman's terms   

[burakkucat]

I know it's just for the attenuation test, but looking forward to see your results but I am sure it will be Technical jargon until someone can break it down into layman's terms   

I know that both our leader, Kitz and a certain analytical Eagle will be ready to consider some more raw data . . . once harvested.

[burakkucat]

At long last, some more raw data has been generated. This time with a local loop length of 400 metres.

The raw data has been submitted to Our Leader, Kitz and the Eagle with a deficit of head feathers. In due course, when the moment is ripe, etc, my two analysts will make their considerations known. 

A quick review shows that the latest firmware image (bcm96368MVWG_fs_kernel_HG612V100R001C01B030SP06_Wolfy_Unlocked) has the best performance, followed by the original firmware image with the updated Broadcom BLOB (bcm96368MVWG_fs_kernel_HG612V100R001C01B028SP10_Asbo_Unlocked_Updated_BLOB) and then the original firmware image (bcm96368MVWG_fs_kernel_HG612V100R001C01B028SP10_Asbo_Unlocked) "brings up the rear".

There is one other observation that I shall mention in this preliminary report -- the overall performance has been severely degraded in going from a local loop length of 1.5 metres to one of 400 metres.   

[Bald_Eagle1]

What can I say, other than just about everything looks 'wrong' in the graph montages.

I suspect the issue has something to do with the cable still being coiled, the particular type of cable or the method employed of jointing the cable & doubling back up & down to make the total length of around 400m.

I wonder if things would look 'better' if the cable was somehow uncoiled?


Attached to this message are the resulting montages from the 3 firmware images (first run).
The next message contains attachments, in the same order, of the repeated tests.

[Bald_Eagle1]

Repeated test results attached...........

[les-70]

   As you say - very odd.  I believe you have a TDR so one potentially easy test would be to look down the "400m" with it and check if there are any reflections other than one at the end on the modem or dslam.  I don't think coiling twisted pair should have much effect.

 Edit: A resistance check may also show something.

[NewtronStar]

A magnetic field will be generated around the coils of wire if you pass a current through them thats my physic's lesson it depends on how much current and other stuff 

[burakkucat]

Good suggestions -- thank you.

The current configuration is:

• end one, green/white striped wire to IDC2 of the LJU2, number one
• end one, white/green striped wire to IDC5 of the LJU2, number one
• end two, green/white striped wire connected to blue/white striped wire
• end two, white/green striped wire connected to white/blue striped wire
• end one, blue/white striped wire connected to orange/white striped wire
• end one, white/blue striped wire connected to white/orange striped wire
• end two, orange/white striped wire to IDC2 of the LJU2, number two
• end two, white/orange striped wire to IDC5 of the LJU2, number two

Time to fit the batteries into the Tester 301C . . . 

[burakkucat]

Using the Tester 301C showed nothing abnormal with the "long local loop". It's "end-point" was clearly visible when a shorting link was applied and removed at the far end.

Leaving the shorting link in-situ, a check with the Ohmmeter 18C showed a total resistance of 338 Ohms. As there are six segments "in the loop" (starting at the green/white striped wire and ending at the white/green striped wire), I guess that 56.33 Ohms per segment is reasonable.

Unless there is some compelling reason for me to measure and record the parameters for each of those six segments in turn, then I'll just "leave things be". The result of testing the three different firmware versions is identical with the results obtained with the "short local loop".