Sorry my friend, this time your intuition is wrong. You should use VGA, LPT, COM, old SCSI and all the likes connectors only in the case you have all the parts, including the parts you need to connect at hand, it is not the cable types for serious soldering, only if that is some world-saving device you are building with them. You also forget that the wires inside it are very very skinny, don't know US standard, but should be like 20-24 AWG or similar. I worked as a IT system guy, please do not remind me about the old connector types. They are gone for a reason. RJ45 is the way to go if it is enough 20 AWG or similar size, automotive or aviation style for more amps. Trailer connectors are made to be used outside in rain and mud, and they work at least "okeyish" in most brutal situations. Aviation style with some protection from rain could be even better.
RJ45 if you do not need protection from mud and rain, aviation or trailer for some protection.
Hey @svp, you are wrong (and correct)- My version with VGA "type" (not sure it is actually VGA, maybe some din type) with 20-24 AWG can carry preamp PS no problem at all, and mine was and is working fine for 20 years! And all parts are and were freely availabe and CHEAP. So dont tell people its not going to work right? You are wrong. It works 20 years. Right? You think not? Show me. I have a working unit, you think its broken? or bad? Over 2 decades? Old connector types you mention that are bad work great...great for a LONG time. Simple and old works a lot of the time. Tell us why "your intuition is wrong"?????? It WORKS. For 20 years. And is cheap and easy. Best DIY gets it done for low cost and easy to create. Like this.
I get it you would not do it the same today but old way works, and is easy to implement.
Of course RJ45 is good now no issues with that. As I said in my earlier post I would use that now. If it was now, I would actually run some power into the green and yellow LEDs on the chassis mount receptacles to show a good connection...super cool!
But it is absolutely WRONG to suggest that my way is not as good as your way or other ways when they all work. My way is super easy to implement, very tight and easy connection. Yours is slightly more difficult but ok too.
I get it you would not do it the same today but old way works, and is easy to implement.
Of course RJ45 is good now no issues with that. As I said in my earlier post I would use that now. If it was now, I would actually run some power into the green and yellow LEDs on the chassis mount receptacles to show a good connection...super cool!
But it is absolutely WRONG to suggest that my way is not as good as your way or other ways when they all work. My way is super easy to implement, very tight and easy connection. Yours is slightly more difficult but ok too.
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@lgreen
There are things that I totally agree with you:
1. If something works, for a day, two or twenty years - it is already success! No matter what, because for new/novel/diy things the most important thing is for them just to work. That is totally engineers mentality and I respect everyone, which has it - just to make things work. If smth works for 20 years - that is achievement.
2. Agree that the solution using CHEAP parts is better than using expensive, if the result is exactly the same - it just works well. I am not snake oil guy.
3. Yes, the bolts on VGA are the good thing, they in most, but not all, cases secure the connection well.
4. VGA type connection is working well, when it is in secure place and is not touched (it MUST be NOT under the table within the reach of someone legs!)
5. No connection is safe from atmospheric conditions. You can rate it IPXX whatever you want, but it has to be in extra protected place, in some extra box or smth.
but here it ends...
Ok, lets be specific for the moment. I am out of the PC hardware business, but really know thing or two about cables
-That cable/connector you showed is the RS232 standard. We, IT guys from the last century used to call the cables by the purpose of their usage: "printer cable" or just "LPT", "COM" or "modem" cable, "VGA" or "monitor", "external SCSI wide" and so on. Of course when buying it you have to specify you need female-male or male-male etc. Now it is easier as 99+% of application of USB-C will be male-male, and there are less standards in common office. Ok that does not matter much. I am telling this to be exact. So the connector in your post was "COM" or RS232. VGA is with 3 rows of pins. I could be wrong about this, because I am writing from memory, I have left that area of work.
-I worked as IT systems administrator for some time, lets say that more than 10 years. At the time when ecosystems were finishing transition from analog-digital to purely digital: phone modems to DSL to some proprietary standards to optics, coax networks to Ethernet (actually CAT5 I think) - we called them like this, because actually it was so huge transition ant the term "Ethernet" was marketed more and so on. Also when transitioning from manufacturers using lead-based soldering to lead-free soldering - that was a HUGE thing. So I definitely know something about connectors. I will not tell about the physics of the signal inside of some cables - I am not oscilloscope guy (will know how to use when needed), but know a lot about practical usage, unplugged/plugged much more cables than average human, by the factor of 10000. Lets say I was server room guy.
-Bad cable/connector is one of the hardest things to troubleshoot. You would not believe in the situations I have been because of some malfunctioning cables: server hardware was thrown or almost thrown away because of some old school 40+ pin cable malfunctioning, sleepless nights spent by me or my colleagues, hours and days spent troubleshooting some software "Error Fx1321 321" messages because of low level hardware faults (also because cables/connectors). There were priorities in the office: Priority 0: viruses, malware, security breach, 1: your backups of the last Friday are done and not corrupt, right? 2: everything works for the feeding hand 3: everything works for the most hysteric persons in office - read: accounting department 4: all the low level stuff is ok in office - connectors, cables, patch cords, nobody touched some "random" cable in some weird place, some electrician did not lay high voltage cable near your data cable, your hard disks did not develop bad sectors and so on, and then everything else. That was the typical priorities or most of the "IT guys". They may change in order a little, but I can tell if someone was responsible for the whole system when he talks about priorities. Deep knowledge of some technical subject matters less than knowledge about the priorities. Yes, that is so simple.
If you worked as IT guy at that times - you will share my pain, but somehow have feeling that you did not.
Now lets go to exact matter of recommending RS232 (or VGA) cable, why I STRONGLY suggest not to use it in DIY applications:
1. Contact area. From my experience the exact contact point of every pin to socked in the VGA/RS232 cable is less reliable than typical RJ45. I don't know why, but my practice shows that. If the cable is connected, works well, signal is of the high quality - then I am happy for it, but when plugging-unplugging many times that standard is inferior to Ethernet/RJ45. That is counter-intuitive, but my practice can say that. Maybe that is because pins are not squeezed enough by the socket or maybe because of the corrosion, or maybe the connection are getting loose or maybe because typical RJ45 usage is Ethernet which more tolerant because of its digital nature. I don't know that. All RJ connectors are spring secured, so if the springiness is less during the usage - in most cases it is still enough for a good contact. In most extreme cases with some skill you can "restore" springiness in socket with some sharp tool yourself, but you cannot do that in VGA cable/socket.
2. Troubleshooting. 2.1 Visibility. Tell me how good the eyesight of average 30+ years guy is? Is it good enough to see inside of each pin in VGA female connector?... RJ connector most likely will be transparent, with all the contact area visible also. Also is visible the contact area of the cable to connector. Transparent RS232 exists, but it is more of a gimmick and exotics, which you have to buy from not-so reliable manufacturer and not-so reliable seller, and still you will not see all the stuff of the RJ type cable 2.2. Electric signal troubleshooting. The only way to troubleshoot VGA type cable is to check pin by pin with some multimeter. RJ ecosystem at least have some tools. There is not much difference if you have just 1 connection, but when hundreds - it does matter.
3. Ecosystem. There is entire ecosystem for Ethernet cables. Off the shelf. Available at literally 10-20min drive from you. Pliers, premade cables of different lengths, shielded cables, shielded separate pairs, POE capable cable, outside cable, inside cable, CAT5e-6-7 or whatever cable, backplanes, sockets, cables of different quality and price - everything is at hand in any electronics store. It is much harder to source smth for "VGA". You are lucky if there is a cable of fixed length. Everything other - big chance that is a soldering job. Also... If you are/were IT guy, you probably learnt to make RJ connector with simple flat screwdriver when no pliers at hand. That was useful skill
4. Resistance to abuse. Have you seen what happens when some strong, big, fast moving, energetic and little heedless guy trips on a cable in some cubical type office? If you do - you know what can happen. In that case bolted on connection is a real hazard. Seriously real. If you are lucky - there will be no injuries or the expensive equipment survives the fall. Don't tell me that typical offices and homes are free form cables. Real life is not. If you are smart enough not to use bolt secured connectors on places where people/pets are walking around near their legs - still RS232 type socket is not capable of much abuse. RJ is the exactly opposite: it holds connection well, but will break when pulled hard. And then you can repair it - read about the ecosystem
5. Voltage. There is POE standard for Cat5(?) cables. It has many limits, but at least you can send some voltage. I know that I used personally 40V for sure. It depends on the separate case how it will be reliable, but still very very possible. Do not know the limits in amps, probably in 1A range, but still something that is ready to use industry standard. To my knowledge RS232 specification is not made for such voltages. So, in the very very extreme case you can send even some higher level signal through RJ jacks. Like music signal to passive speakers. That is not a huge advantage, as I do not see the reasons why not RS232 is not suitable for bigger currents and voltages, just you will have to figure yourself - yet another task.
and now the most interesting part..
6. Soldering of connector. I want to see that! RS232 is 9 pins 2.8mm apart. That is masochistic enough. As you don't know a thing about the standards - "VGA" is 3 rows, 15 pins hell spaced 2.29mm apart, that is less than 1/11th of inch. Can you post how you are soldering middle 5 pins in the connector or socket at home? I want to see really good strong soldering, good strong ready to use homemade cable, soldered to the connector or socket with lead-free solder, not the "look Mom, it sticks!" job. You will earn my praise.. If you do that - I can make a video, how I make CAT5 cables, I have pliers somewhere laying around. We can then post the results here, some videos of pulling them them from sockets with a little force, bending them, twisting - like all the typical usage. Then make a poll for members to vote which of our DIY struggle is better or more "audiophile". Actually I will make couple, as 8x2 is almost the same as 15pins of VGA. With no cheap cheating, like using terminal blocks with bolt-on connection plates behind the socket and so son. Just the pure homemade welding 15 pins 1/11th inch apart vs me using pliers.
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There are conditions for each connector usage. When you have some equipment with VGA or RS232 sockets - then yes, probably you have no choice than to use it. Also when you already done the task and it works, I am not saying that you have to re-make something. Yes, most connectors are absolutely good when they work, are in perfect atmospheric conditions and you don't need to touch them. But when there are more requirements than this - I want to protect someone from making masochistic choices. That is similar to recommending chipboard over plywood for speaker cabinet. Chipboard is better only on very select conditions, like: you have it at hand, short on money, you like it more visually or other subjective things.
I wrote such a long text for someone who will have the similar problem and he has to chose simple solution vs complex one.
p.s. one of my relatives is a jeweler - he actually can solder any reasonably complex connector, but how many average guys have someone to help with such tasks? Is it necessary to put yourself in the situation where you need to make such choices?
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eBay has some good choices. I searched for "waterproof connectors pair" and got a bunch of affordable newly-made ones. Types include IP28, SA28, SF6 (which I've used successfully but max out at 5 or 6 pins) and WS20. Some examples, which I expect are also on the Asian merchant sites.
https://www.ebay.com/itm/1944866530...ZswsV6mPAIT6z5e8aElOjoPsE=|tkp:Bk9SR_Dj442uZQ
https://www.ebay.com/itm/3551518533...onlnleEwIp2szgHOA7gVbxvgg=|tkp:Bk9SR9zPl46uZQ
https://www.ebay.com/itm/1944866530...ZswsV6mPAIT6z5e8aElOjoPsE=|tkp:Bk9SR_Dj442uZQ
https://www.ebay.com/itm/3551518533...onlnleEwIp2szgHOA7gVbxvgg=|tkp:Bk9SR9zPl46uZQ
Not always - the total resistance of the cable depends on the gauge and the length - if you want to limit voltage drop across the cable you may have to use wires thicker than needed for safety. Calculate the allowable cable resistance from the voltage-drop requirements, then use that to check if the gauge is adequate. Low voltage power distribution is often voltage-drop-limited, not current-limited.
This is why the modern approach is point-of-load voltage regulation, which allows larger voltage drops on the wiring by placing the final voltage regulation at the load.
I was assuming he was running some low voltage, low power from a preamp to power amp, so probably not running metres of cable.
16awg is comparable to 1.5mm cable, a quick google suggests 1.5mm cable is good for ~15A .
I would suggest that is way oversize for what is needed in his application ?
Rob.
16awg is comparable to 1.5mm cable, a quick google suggests 1.5mm cable is good for ~15A .
I would suggest that is way oversize for what is needed in his application ?
Rob.
Still you don't want to drop much voltage on a 5V supply, common specifications are 4.75 to 5.25V tolerance range, you want to aim for < 0.25V drop across power and ground wiring and connectors in total. 0.1A was mentioned. Many small connectors have significant resistance, its not just the wiring to worry about with low voltage distribution.