3 ms·

Why not just go with RJ11 (6P4C) instead? The PCB mount connectors are cheap, cables are easily available even from most local electronics stores, up to 10m len

Why not just go with RJ11 (6P4C) instead? The PCB mount connectors are cheap, cables are easily available even from most local electronics stores, up to 10m lengths.

kragen 3y ago
yeah, rj-11 or 4p4c ('rj-9') are the other candidates, and they have some real advantages over 3.5mm jacks: - cables are available even from hardware stores, and also so are bus adaptors which connect two or three or five cables together, pin for pin; these do exist for 3.5mm jacks but are less common - spiral 4p4c cables are cheap and easily available - it doesn't short the power rails together as you're plugging it in - the cables are all pretty high quality, which is not true at all for the 3.5mm audio cables they also have some disadvantages: - the cables are much larger than 3.5mm cables - the jacks are much larger than 3.5mm jacks - instead of absentmindedly plugging earphones into my data logger or programmable load and blowing up the earphones, the danger is that i (or a child, say) might absentmindedly plug the data logger into the phone jack on my cable modem, which is something like 50 volts on-hook and 90 vac when it rings - 3.5mm jacks are an evolution of phone switchboard connectors, so they should be good for thousands of insertions and the plugs for like a million or so, and i'd be surprised if rj-11 or 4p4c connectors made it to hundreds
- formerly_proven 3y ago
  Reliability of 3.5mm vs phone jacks is probably pretty similar (500-1000 cycles?), 1/4” jacks, at least the good ones like Neutrik, brag about >10k cycles. I think there’s a reason audio patch panels used either 1/4” or Lemo. I expect far more reliable contact from RJ preloaded contact springs compared to 3.5mm, which are noisy when disturbed even when new. You could use 4P4C, the handset connector, instead of RJ11/6P4C, the phone line connector. Reasonably common, and no risk of ever plugging in a phone line.
  - kragen 3y ago
    you might be right, but regular plugging and unplugging is a part of the normal usage of the cylindrical connectors in a way it isn't for the modular telephone installation stuff. the tabs do sometimes break off, but i think that's a question of abuse (dragging them backwards through a rat's nest) rather than wear or defects (i assume by 'phone jacks' here you mean rj-11 and 4p4c, but https://en.wikipedia.org/wiki/Phone_jack https://en.wikipedia.org/wiki/Phone_jack lists cylindrical 3.5mm and ¼” 'phone connectors' as well, because they originated in telephone switchboards) you can actually plug a 4p4c plug into an rj-11 jack, or even an rj-45 jack; it enters and holds securely. it may damage the rj-45 contacts, but it will fit. but it's probably true that it's a less likely error for someone to make in practice, and i wonder if maybe the higher on-hook voltages aren't even passed through to the handset another plus of the modular phone connectors is that they're significantly less work to attach to a cable than a 3.5mm plug, once you have the right crimping tool anyway. (you'll get a shitty connection until you learn to do it right.) otoh, the 3.5mm plug doesn't need a crimping tool

Why not just go with RJ11 (6P4C) instead? The PCB mount connectors are cheap, cables are easily available even from most local electronics stores, up to 10m lengths.

kragen 3y ago

yeah, rj-11 or 4p4c ('rj-9') are the other candidates, and they have some real advantages over 3.5mm jacks: - cables are available even from hardware stores, and also so are bus adaptors which connect two or three or five cables together, pin for pin; these do exist for 3.5mm jacks but are less common - spiral 4p4c cables are cheap and easily available - it doesn't short the power rails together as you're plugging it in - the cables are all pretty high quality, which is not true at all for the 3.5mm audio cables they also have some disadvantages: - the cables are much larger than 3.5mm cables - the jacks are much larger than 3.5mm jacks - instead of absentmindedly plugging earphones into my data logger or programmable load and blowing up the earphones, the danger is that i (or a child, say) might absentmindedly plug the data logger into the phone jack on my cable modem, which is something like 50 volts on-hook and 90 vac when it rings - 3.5mm jacks are an evolution of phone switchboard connectors, so they should be good for thousands of insertions and the plugs for like a million or so, and i'd be surprised if rj-11 or 4p4c connectors made it to hundreds

formerly_proven 3y ago
Reliability of 3.5mm vs phone jacks is probably pretty similar (500-1000 cycles?), 1/4” jacks, at least the good ones like Neutrik, brag about >10k cycles. I think there’s a reason audio patch panels used either 1/4” or Lemo. I expect far more reliable contact from RJ preloaded contact springs compared to 3.5mm, which are noisy when disturbed even when new. You could use 4P4C, the handset connector, instead of RJ11/6P4C, the phone line connector. Reasonably common, and no risk of ever plugging in a phone line.
- kragen 3y ago
  you might be right, but regular plugging and unplugging is a part of the normal usage of the cylindrical connectors in a way it isn't for the modular telephone installation stuff. the tabs do sometimes break off, but i think that's a question of abuse (dragging them backwards through a rat's nest) rather than wear or defects (i assume by 'phone jacks' here you mean rj-11 and 4p4c, but https://en.wikipedia.org/wiki/Phone_jack https://en.wikipedia.org/wiki/Phone_jack lists cylindrical 3.5mm and ¼” 'phone connectors' as well, because they originated in telephone switchboards) you can actually plug a 4p4c plug into an rj-11 jack, or even an rj-45 jack; it enters and holds securely. it may damage the rj-45 contacts, but it will fit. but it's probably true that it's a less likely error for someone to make in practice, and i wonder if maybe the higher on-hook voltages aren't even passed through to the handset another plus of the modular phone connectors is that they're significantly less work to attach to a cable than a 3.5mm plug, once you have the right crimping tool anyway. (you'll get a shitty connection until you learn to do it right.) otoh, the 3.5mm plug doesn't need a crimping tool