P6015 cable connector (tektronix HV probe) and a repair tip - Page 1
Forum section: electronics / repair

author: coppercone2
author_rank: Super Contributor
timestamp: June 13, 2023, 02:27:07 am
content: So I got the little ground thing and refilled it with silicone oil to only have a tiny drop of air in there butThe coaxial cable is frayed so I bought a new compensation box with a nice cable butI need to know what the fuck this connector is.I tried to desolder it for a long time, it looks like a ceramic insulated coaxial cable thing. So there is a ferrule thats crimped over the outer bit, which I pulled off, but the inside pin is baffling, and I managed to rip the thing from the other side out trying to yank it out when it was screaming hot. It looks like there is a cross of copper inside of the ceramic insulator.Do they thread the wire through, then crimp both the shield and the center wire?I want to know what this connector is called. It looks kind of like a BNC but its ceramic and dual crimp.If you have one that you want to save, you can probobly recrimp the ferrule if you find one similar, but for the center pin... what I would recommend, I destroyed mine.. is to yank out the wire, then use a sensitive drill press to drill out the middle, then thread the newly stripped wire in there and solder the inside. It won't be as strong as whatever they did but it might save you a couple of dollars.I don't need a replacement one because I already ordered it, but I want to know WTF it is. I figure it must have been common back in the day. Its really pissing me off.

author: Gyro
author_rank: Super Contributor
timestamp: June 13, 2023, 08:11:10 am
content: That will be a Tektronix custom part. The centre conductor could well be resistive (corrugated Nichrome or whatever) like their other scope probes, for best damping, so it may well not be solderable.

author: coppercone2
author_rank: Super Contributor
timestamp: June 13, 2023, 11:53:19 pm
content: you are right it is resistive and that means that they may have brazed it and it explains the ceramic part. I wish i drilled it before destroying it. Or it could have been crimped.I am very suspicious its brazed since they had ceramic there.I suppose it would be as simple as putting a small tube in there, then swaging it on both ends. And then hit it with like a micro flame...Now that i renembered the center conductor is a bastard to solder, i feel alot better about just buying the part lol I forgot about the resistive probe wires and it started to look like lunacy.But there is one interesting repair possibility, to thread it through, put a dash of epoxy in there to hold it, then spot weld a copper strip to the end. But its kinda janky IMO.Since I have the 10 feet of cable I can try to spot weld it to see what happens for curiosity.Oh I actually probed it. The star shaped thing, I thought that was adhesive or some kind of residue because its dirty, there is acutally copper still there. Its like a nautical star/flower in 3d thats cut in half so its hollow that is made of copper and sunk into the ceramic.I can try to fix it. Might be faster to repair this probe then I thought, good place to start electronics spot welding experiments on. But I would still need to guess about which collar and crimp tool to use on the braid and do alot of research on what connector could be canibalized without risking the crimp tool.My best idea so far:1) crimp a center conductor off a fitting coaxial connector to the center wire with a 4 indent crimp.2) put solder paste on the bottom of the crimp and pull the wire into the swaged copper tube on the inside of the ceramic flower shape3) heat for melting, also melting a preform and a loop of wire to the center pin. Or use a too small copper center pin like a SMA interior, and just solder it into the tube after crimping, and stick a wire into the receptacle end of the center pin and solder it again.I have my doubts about getting a good crimp on the nichrome wire though, if you just guess on a random center pin to use as an anchor. Probobly not worth the effort and I don't want some obvious point of failure to possibly read a high voltage circuit as de energized. I know that the probe should not be the primary means of verification of the presence of high voltage, but it just seems like its removing a possibly contingency.If it was anything but a 20KV probe I would try the repair out.I think for a HV probe, a dodgy connection point that is in series with the measurement equipment is the worst, because you can disable it to the point of failing to detect HVDC, which is quite 'broken'. And this probe cable is kind of stiff and shitty anyway, the one I got looks alot less degraded.But for those interested, the inside of the probe has a hair thin single strand as the center conductor. The AWG is really small. I think it might be thinner then a braid wire. Fuck dealing wiht that

author: coppercone2
author_rank: Super Contributor
timestamp: July 02, 2023, 06:34:23 am
content: I got another repair tip slide a teflon sleeve over the 150 ohm resistor in the body of the BNC cable connector because the construction method is insane, they just bend a lead over that you fold into the chassis when it closes. they must have been passing high balls out in the office when they got approvedso basically when you close it do a continutiy check and a visual inspection to make sure there is no short circuit when you bend it closed. you can poke at it with a dull stick to get rid of the short but its really bad that they could not put a piece of tubing over that lol, its like peeping through a door jam or something, really bad, it tends to move into short circuit right when you tighten the screwsand the method of keeping the module together is creative. idk why they did not make it so you remove a side of the box to get a side ways view of the circuit, instead of compresses a stack of weird shit on stand offs. like mechanically the probe compensation box is really dodgy IMO, there is no super structure or back bone, its just a sandwich, and its super annoying to reassemble. like damn wtfand the spare parts unit I got was so corroded it looks like someone just poured baking soda in there I mean it was caked with white shit luckily the cable was OK. I mean like 2mm of powder. I thought i was gonna keep it for the capacitors or something but IDK what is going on there worst electronics corrosion i have seen I think, shit looks like a leaked alkaline battery but there is no battery lol

author: mikehank
author_rank: Regular Contributor
timestamp: July 09, 2023, 01:26:20 am
content: My suggestion with the P6015(A) is to not repair. These are VERY high voltage(25kv AC and 40KV DC) probes and safety is HUGE. I know we all like to fix any and all things we can but in this case i would be a nope. Please be safe.

author: coppercone2
author_rank: Super Contributor
timestamp: July 09, 2023, 01:41:09 am
content: more like modify. IDK I read the app note 108 by Beverly III & Associates on how to replace the freon with silicone oil and modify the tuning network to get it to work right.If by repair you mean plastic weld, then yes, I would definitely not do that.And the amount of corrosion in these probe adapters can be so ridiclous that I would argue that taking it apart and cleaning the thing is increasing the safety factor because might actually have a ground if you do that.