Tektronix 1503B

[@joshuawalker7054]

I used to use these in the Navy. I worked on the EA-6B and used this to see how buried in the airplane a fault in a coax line was.

[@pengiswe]

A great tool! Gives me a lot of nostalgia. Was using that exact model when measuring cables. We got one to a radio club when we needed to length match coaxial cables to a cross yagi antenna, so we could get a known phase shift of the cables. If I remember correctly, it was possible to get close to millimeter accuracy. At least centimeter. The cables we needed to measure was in the range of 50m to a 2m antenna (145MHz), so centimeter accuracy would definitely be enough. I also remember once I was borrowing that one to another radio club in the area IIRC. At least that was the plan. They had a broken antenna cable to one of their towers, that was broken somewhere under ground. And they needed to know where it was, since they didn't want to dig up everything. So it could be used in the intended purpose of the instrument. Albeit a bit overkill, but really useful when sorting antenna cables just to get a quick idea of the cable lengths without unrolling them. Would love to find one of those in the dumpster to repair myself :D Thanks for the video, and congratulations for a successful repair and great instrument.

[@hymermobiler]

Didnt know they existed but another fascinating watch thanks

[@valmonta3647]

Another beautiful work from atkelar

[@jorgedanielcorvatta1317]

Thanks for reminding me of this equipment, I used it in the 90s along with another one to measure optical fiber, great job. Congratulations.

[@parkerlreed]

What a beautiful machine. Great restoration!

[@graemedavidson499]

Great job - well done! I love the TDR built into my Fluke network tester. It’s great for determining the distance to CAT 5 cable faults! They never seem to be far away from disturbed ceiling tiles or other conspicuous building maintenance ;)

[@atkelar]

Indeed, many newer devices have these things built in as an extra... I wouldn't be surprised if there's a single chip solution out there somewhere. But this is a nice retro machine that does the trick, so a nice addition to my collection.

[@KeritechElectronics]

Great restoration job on a lovely piece of kit! :)

[@MagicMaus29]

If you treat the rubber with cold spray between passes, you can safely remove more material per pass.

[@atkelar]

Interesting idea... I'll remember that for the next project where I need that stuff!

[@krandall5285]

I can't speak to the green overspray, but I would bet that the other is Aviation Safety Orange. These were commonly used at tower sites and lots of tools, and vehicles for that matter, in the tower maintenance trade tend to get orange and white overspray.

[@laytondrake289]

I just recently discover your channel and saw a few videos of these and man you check all my boxes. You earn my sub!

[@atkelar]

Just be mindful that the (mostly) same background elevator music might not be the best to binge 😊

[@laytondrake289]

​​​​@@atkelarPerhaps lower the volume or change the music to have variety? Not sure on that part. I found your channel randomly because I too am into the repair hobbyist community and super glad I found one that focus on retro tech. If you know any channels to learn from or a discord group to follow please let me know. I am also thinking to maybe start a repair business, but I'm not sure if I can pull it off as of yet, so this channel will help me a lot learning this trade. Your cat puppetry in your thumbnail did made me curious to explore your channel, very unique approach, I like it. Very charming, it adds character or a brand to your channel. Is like watching a puppet show focus on electronic repair in a retro 80s style, excellent, as I said you checked all my boxes to follow your work.

[@TheDefpom]

Nice fix, good work on the display and roller.

[@rallymax2]

Really nice restoration on this one. Tricky lcd strips for sure.

[@zyeborm]

If you're getting big sparks like that when your doing the spot welds it's an indicator the material isn't clean enough or you don't have enough pressure btw. I found you really want quite a lot of force and an alcohol wipe to get the oils from fingers off helped a lot. A good join should rip the metal out of the strip leaving it on the battery when you peel it off.

[@atkelar]

Interesting. Thanks for the tip! Since I was pressing down as hard as I dared (without bending the tips) It might be a cleaning issue. I didn't show it, but I used some sandpaper to roughen up the surface a tad before welding, so I would get rid of any ox but just brushed off the dust.

[@zyeborm]

Probably the dust then or the surface roughness? You really want intimate contact. It is pretty to watch the sparks though, not gonna lie 😂 But yeah, do a sacrificial pull test (perhaps on the dead batteries) to ensure you're getting a good weld. (Like it's probably totally fine as it is, just suggestions if you want to for next time.)

[@shuichinz]

Nice just found your channel! subscribed! The green and orange paint will be from when it was used in a cable/fault location kit for underground electrical cables for marking out the cable

[@JeffreyGroves]

The specks of paint are likely from cable locate activities where they paint the ground where the cable is running.

[@atkelar]

It does seem like the most plausible explanation... but since I don't know where the unit was used, I wouldn't declare it official 😅 - It certainly had most of the tiny specs on the front panel, so the lid was off during "paint use". Quite hard to remove without scratching up the panel.

[@Pulverrostmannen]

I seen a tool like this in action too! really nice to have I bet. I really hate the rubber rot issue with older devices. so many of my things have gotten destroyed by this. valuable hard drives, tape recorders. record players you name it. and you can't really take a hard drive apart without making severe damage to it trying to clean or replace the melted rubber mess inside. ugh

[@ketturi]

Yikes, I would not have had patience with that LCD panel. I wonder if there are any modern LCDs with close enough dimensions that could be fitted as a replacement, would need a custom adapter board most likely tho. Interesting how the display fades when the printer is running, that motor and print head must be power hungry. Hearer under the panel is must have, you do not want to wait several seconds between every display refresh while working outside in freezing temperatures. I remember cursing when the mobile phone display would not update while trying to call somebody to pick me up while standing in -30C snow storm 😅

[@atkelar]

I was looking at optinos for replacing the display indeed. But there is no single one that is the right size and resolution. Either half the size and same resolution or around full HD for the same size; including RGB and complicated controlling at 3.3V... so level shifter, homebrew controller... it adds up quickly.

[@pvc988]

I had no idea rubber could be cut with a lathe just like that. I think I have some more stuff to repair now :)

[@atkelar]

It was an experiment. Results may vary, but it's worth a try at least!

[@pvc988]

@@atkelar I tried it and it sure works for hard rubber mixes. And for softer ones, I need to get me some dry ice and try again with rubber cooled down.

[@arampak]

A modern nanoVNA does this and much more. In fact, this is a specialized VNA device. But of course that is not diminishing the excellence of the recovery effort and the historical value of the instrument.

[@atkelar]

Thanks! I'm aware that many newer instruments are more versatile and probably more accurate too, but to me, it's the "hey, look at what this old piece of equipment can do" just as much as the restoration and video making.

[@dcallan812]

Nice work. 2x👍

[@Coalrollinfurry]

Furry tear downs. Sounds good.

[@jmpeax3596]

Nice restoration. How did you fix the LCD eventually? I watched it twice in case I had overlooked something, but after the "a few days later" at around 21:58 the display still does not look right.

[@atkelar]

Just persistant cleaning of the contacts really. I had to resort to the glass fiber pen with the line driver connection (the flat flex cable) - the reason there is no earlier "success" shot is mostly me, misplacing the picture; I am sure I had one but all I found when editing was the "completely assembled" one and that would have been out of order quite badly.

[@llloyd4]

Beautiful machine. Though I don't think I want to know what the shop smelled like when you lathed that rubber. :D I'm envisioning burnt rubber. :D

[@atkelar]

Well, it's some "rubber like stuff" - I'm calling it rubber because I have no better name for it. But it is basically the stuff that I think most pinch rollers and similar stuff is made of. And the tool was sharp enough to really cut the stuff, it didn't smell too bad at all.

[@inse001]

Who has already found out what the 1503 is? Logic Analyzer? TDR cable tester - not the usual instrument

[@bobcat_the_Lion]

It is a piece of equipment to find breakages or shorts in (for example) coaxial cable or telephone line. Very handy is the cables are burried. A short pulse is sent along the cable. The pulse moves alongside the cable with the speed of light (minus a correction factor) and when it finds a change in the impedance (for example due to a breakage) the pulse is reflected. If you measure the time between sending and receiving the pulse, you know at what distance the cable is broken.

[@sideburn]

I wonder if printing a pinch roller out of TPU would have also worked… Having shop tools like a lathe comes in handy! One of my missing links. Some day I’ll have to make room for machine tools.

[@atkelar]

A 3D print might indeed work, but I never tried flexible materials before (I have a sample but didn't get around to it yet) - this rubber stuff I got was mainly intended for replacing pinch wheels in record players or similar applications. And I think it will work a treat for that. I'm still surprised at how well it machined, well, compared to the expectations at least :D

[@sideburn]

@@atkelar yes your route was much better than 3D printing for sure. TPU is a bit more like flexible plastic and may not have enough grip to it.

[@ScottDotDot]

Great job with the LCD despite it being such a pain, it came out perfect. Just curious, why did the battery module have a heat sink? Voltage converter?

[@atkelar]

The case (and battery compartment) is hermetically seald and these get warm during charging. The metal bars and heat sink are a way of getting the heat out without air ducts.

[@FluffyTheGryphon]

How do you track screw locations and such when you do a breakdown of this scale?

[@atkelar]

Usually, I hold the screw into the camera view for reference, unless it is very clear where they go. The filming helps during assembly. Mind you, some washers seem to be very random to begin with, so those usually are what is left over 😸

[@DanielM111]

How was the display tested to see if all pixels are working while having it disassembled?

[@atkelar]

that's why it took so long... I had to assemble the driver boards, solder it back together and run it on the device... What made it slightly easier was that it is either a row or a column missing; actual individual pixel errors would be inside the glass, so not fixable.

[@tim0steele]

Would it have been worth using NiMH cells instead?

[@atkelar]

I would love to replace my NiCd cells with NiMH ones, as they are more readily available... but I keep reading mixed reports about compatibilty with regards to charging. From: "No problem", to: "your device might catch fire!" I have seen everything. So unless there's an easy fix for that somewhere, I keep the originals when possible.

[@thowij]

​​​@@atkelar from experience: it depends, both is possible depending on the charger. The technologies have similar enough characteristics that it can work without any issue. It can also mean that the NiMH cells can overheat within minutes of charging and potentially cause fire. Because it's a hit-and-miss type of situation I very much prefer to use the same battery technology wherever possible.

[@atkelar]

Most NiCd charging circuits I see are just some current limiting elements. Typically just a resistor in series with the incoming power supply, and the more fancy ones have a transistor as a constant current source. Neither has a cutoff, which seems to be required for NiMH?

[@thowij]

@@atkelar NiCd should ideally have a cutoff as well as they don't like to be trickle charged for longer periods of time. NiCd is a bit more forgiving than NiMH, those _really_ don't like it. Some laptops I worked on (like a Toshiba T1600 a couple years back) have some smarts in their NiMH charger and switch in more current limiting resistors when the batteries near full charge. I've seen this on some NiCd based chargers as well (e.g. Toshiba T1000). The NiMH packs do contain some form of thermal protection to prevent overheating whereas the NiCD ones don't.

[@tim0steele]

@@atkelar Would it be possible to trace the charging circuit in the unit?