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[Bald_Eagle1]

We have all no doubt heard or read about the effect on DSL connections of switching on a plasma TV.

Well, here's some graphical data of that effect from a connection Walter's wheelbarrow has been monitoring recently.

We believe there may also other physical factors at play such as bridge tap(s) as evidenced in the Hlog graphs.
Somewhat surprisingly, the Hlog graph looked quite perfect for a 1500m connection for a brief period (only 3 minutes).

A plasma TV shouldn't have any effect on the physical line properties, but the evidence is that it certainly has a negative effect interference-wise.

In order, see the attached graphs:-

1) Hlog - Bridge tap effect
2) Hlog - No bridge tap effect
3) snapshot montage - bridge tap effect
4) snapshot montage - no bridge tap effect

[Bald_Eagle1]

Further to the above post, see the ongoing montage for all 5668 samples obtained for this connection.

The gap in the graphs was from a power cut

[burakkucat]

Veering somewhat OT, I have analysed the data that produced the Hlog graph which shows a strong presence of a bridging tap.

There are two minima clearly visible, at tones 267 and 571. The delta is 304. By usage of a table from a JDSU Application Note (Table 2 of JDSU-sctpsbridgedtap_an_tfs_tm_ae.pdf, a.k.a. Application_Note_Detecting_Bridged_Tap_And_Noise_Interference.pdf, a 1 MB file -- too large to attach here), we can estimate that there is a bridging tap of approximately 76 metres length connected to the pair.

[Bald_Eagle1]

The mystery is though, what could have caused the bridged tap effect to disappear, albeit only for 3 minutes?

FWIW, I forgot to add that the connection is around 1500m in length.

[burakkucat]

The effect of human fingers, sheepish hooves, avian beak or feline paws, maybe?

As those results are by remote analysis, only an actual physical examination may disclose the truth.