4 ms·

In the same vein of interesting experiments on weird cables: ADSL on wet string: https://www.revk.uk/2017/12/its-official-adsl-works-over-wet-string.html https

In the same vein of interesting experiments on weird cables: ADSL on wet string: https://www.revk.uk/2017/12/its-official-adsl-works-over-wet-string.html https://www.revk.uk/2017/12/its-official-adsl-works-over-wet...

bee_rider 2y ago
Makes you wonder what’s going on when you do get a crappy connection.
- Epa095 2y ago
  The string is dry.
- Loughla 2y ago
  Honestly, before we had municipal fiber, I'm pretty sure our connection was wet string. Rural living does have its drawbacks.
- nick7376182 2y ago
  What is the impedance of a gopher's teeth?
- dfox 2y ago
  Crosstalk or other interference coupled from the outside into the line. The telco grade twisted pairs do not really behave like twisted pairs (that cancel out the external coupling) at the frequencies used by xDSL.
Simon_ORourke 2y ago
My gawd, now I've seen it all! That's one step up from digital transmission via pigeon.
kqbx 2y ago
Reportedly, ADSL can work even if there is a short (~5mm) gap in one of the conductors (because of capacitive coupling). source: Someone said this on reddit so it must be true https://www.reddit.com/r/networking/comments/7jj7ap/comment/dr6rihi/ https://www.reddit.com/r/networking/comments/7jj7ap/comment/...
- exmadscientist 2y ago
  If one wire in the pair is still connected, it's not really working because of capacitance (which is ~nil at 5mm), it's working because diff pairs are amazing. The remaining signal level on the single wire was probably enough to keep the receiver happy (at ~10kBaud in the Reddit post, versus the design ~100MBaud), and so, you win. Any time you can spare the pins & wires to go differential, and have the slightest hunch you might need it, just do it. Diff pairs work!
- thfuran 2y ago
  Old analog tv over coax used to work with the cable poorly seated. You could even disconnect the cable entirely and just point the conductor at the plug and still get a(n admittedly quite noisy) picture as long as the cable end was near enough.
  - Arrath 2y ago
    Okay, that's pretty cool
  - Retric 2y ago
    I had that happen as a kid and never figured out what caused it. My Atari was giving a very snowy image but I kept playing for a while. After dying I go to fiddle with the cable and it’s not even plugged in. Honestly kind of messed with me at the time especially as I couldn’t replicate it.
jwilk 2y ago
Discussed on HN: 2017: https://news.ycombinator.com/item?id=15908107 https://news.ycombinator.com/item?id=15908107 2021: https://news.ycombinator.com/item?id=29440681 https://news.ycombinator.com/item?id=29440681 2024: https://news.ycombinator.com/item?id=40387318 https://news.ycombinator.com/item?id=40387318
ooterness 2y ago
There's also "28Gbps Microstrip With Pepper Jack Cheese as Substrate" https://www.linkedin.com/pulse/28gbps-microstrip-pepper-jack-cheese-substrate-ryan-lott https://www.linkedin.com/pulse/28gbps-microstrip-pepper-jack...

bee_rider 2y ago

Makes you wonder what’s going on when you do get a crappy connection.

Epa095 2y ago
The string is dry.
Loughla 2y ago
Honestly, before we had municipal fiber, I'm pretty sure our connection was wet string. Rural living does have its drawbacks.
nick7376182 2y ago
What is the impedance of a gopher's teeth?
dfox 2y ago
Crosstalk or other interference coupled from the outside into the line. The telco grade twisted pairs do not really behave like twisted pairs (that cancel out the external coupling) at the frequencies used by xDSL.

Simon_ORourke 2y ago

My gawd, now I've seen it all! That's one step up from digital transmission via pigeon.

kqbx 2y ago

Reportedly, ADSL can work even if there is a short (~5mm) gap in one of the conductors (because of capacitive coupling). source: Someone said this on reddit so it must be true https://www.reddit.com/r/networking/comments/7jj7ap/comment/dr6rihi/ https://www.reddit.com/r/networking/comments/7jj7ap/comment/...

exmadscientist 2y ago
If one wire in the pair is still connected, it's not really working because of capacitance (which is ~nil at 5mm), it's working because diff pairs are amazing. The remaining signal level on the single wire was probably enough to keep the receiver happy (at ~10kBaud in the Reddit post, versus the design ~100MBaud), and so, you win. Any time you can spare the pins & wires to go differential, and have the slightest hunch you might need it, just do it. Diff pairs work!
thfuran 2y ago
Old analog tv over coax used to work with the cable poorly seated. You could even disconnect the cable entirely and just point the conductor at the plug and still get a(n admittedly quite noisy) picture as long as the cable end was near enough.
- Arrath 2y ago
  Okay, that's pretty cool
- Retric 2y ago
  I had that happen as a kid and never figured out what caused it. My Atari was giving a very snowy image but I kept playing for a while. After dying I go to fiddle with the cable and it’s not even plugged in. Honestly kind of messed with me at the time especially as I couldn’t replicate it.

jwilk 2y ago

Discussed on HN: 2017: https://news.ycombinator.com/item?id=15908107 https://news.ycombinator.com/item?id=15908107 2021: https://news.ycombinator.com/item?id=29440681 https://news.ycombinator.com/item?id=29440681 2024: https://news.ycombinator.com/item?id=40387318 https://news.ycombinator.com/item?id=40387318

ooterness 2y ago

There's also "28Gbps Microstrip With Pepper Jack Cheese as Substrate" https://www.linkedin.com/pulse/28gbps-microstrip-pepper-jack-cheese-substrate-ryan-lott https://www.linkedin.com/pulse/28gbps-microstrip-pepper-jack...