Mystery Unipan Typ 510 ultrasonic testing unit. Teardown is coming - Page 1
Forum section: electronics / testgear

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 10, 2014, 06:17:30 pm
content: EDIT: You can head straight to the Teardown:Pt. 1: Overview of the outsidePt. 2: Sneakin' inPt. 3: What's inside the cans?Pt. 4: Investigating the inner constructionPt. 5: Power Supply PCB & High Voltage CanPt. 6: Signal generation, conditioning and receivingPt. 7: Beam deflection circuitryGot again something from ebay. 27€ delivered, I know what it is and I know I cannot use it anyways. And I know from the auction text it is broken. But I am sure Dave did not tear down something like this before. Can YOU guess what it is from the pictures?I bought it because I think it is interesting to take a look into and maybe its reselling price is way higher if it works again. Or I will find some interesting stuff in there to rip out. We will find out soon, but not today. Today only the sneak peak photos to get you curious. I got an ambulant surgery (again) on my ankle joint and officially have to stay in bedManufacturer is Unipan in Poland, this thing is from 1984, at least the labels state that. Price back in the days must have been close to 5 digits or above.If you have any information on Unipan, please let me know! I know by now they were a daughter-enterprise of the institute of physics at the polish academy of sciences. Does anyone know about a website on Unipan or have any more info?I am sorry the pictures are not that great but I have to hurry as the painkillers will stop working soon. Teardown pictures will be way better.Good luck with guessing!

author: madires
author_rank: Super Contributor
timestamp: February 10, 2014, 06:33:04 pm
content: Ultasound based detector of ruptures in metalwork?

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 10, 2014, 06:43:10 pm
content: Ultrasonic welding inspection?

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 10, 2014, 09:00:05 pm
content: I should not have given you the type number. Too easy for you guys! But too hard for my brain to think about that while on painkillersYes, it is a device forultrasonic testing.If I understand the frontplate right it can do testing with a single testhead like shown in the article, testing trough the DUT with a split testhead and even determination of the speed of sound in the DUT. Maybe I can get it back to life and get me a testhead to play around a bit. Did this at university some day and was quite interesting.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 11, 2014, 02:24:59 pm
content: I have a little problem. Maybe this becomes a REAL teardown. I don't know how to open this thing upAny Ideas? My only guess right now is taking off the front plate somehow. Not sure this is possible. There is not a single screw on the dark case. How am I supposed to service this beast?!

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 11, 2014, 02:29:47 pm
content: Something under the feet? It looks like the case could slide off the back...

author: free_electron
author_rank: Super Contributor
timestamp: February 11, 2014, 03:20:38 pm
content: Diskgrinder and a box of hammers

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 11, 2014, 04:33:22 pm
content: Quote from: PA0PBZ on February 11, 2014, 02:29:47 pmYes, thought that, too. But the feet cannot be taken off. The edges of the standoffs on the back are covered in the same material as the feet and are screwed into place from the backside - I am pretty sure the same thing is done with the feet. Once opened I will find nuts or screws to undo the feet if I really want to.The cover of the screen pops off easily, making room for the screen to slide back into the case. I think I will try to get all the knobs off the frontplate and try to disassemble the thing that way. I am not sure but I think I can see some screws behind there.Quote from: free_electron on February 11, 2014, 03:20:38 pmThat'll be the last solution if nothing else works!

author: SeanB
author_rank: Super Contributor
timestamp: February 11, 2014, 05:43:56 pm
content: Slide the insert in the middle of the feet out, and then you will find the screws that hold the case and the feet together. They might be very tight and need a little persuasion.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 11, 2014, 06:07:07 pm
content: Quote from: SeanB on February 11, 2014, 05:43:56 pmNope, that's not the way to go! The insert has two (!) threaded pins on it sticking into the case. One is only for keeping it alligned, on the other one a nut is screwed from the inside. Same construction on the standoffs on the back.I finally managed to get in - at least a bit. See that big round thingie in the middle of the back? That is actually a screw! I could easily turn it into both directions when I unboxed the device and therefore thought it had no real meaning or was something to carry fuses or stuff but sealed with an o-ring. I tried to get it loose by pulling and whatever (don't ask!) but nothing would happen. After lots of turns I realized the back was a bit loose but could not be pulled off. Some more turns and there it was...So let me start a real teardown with my next post.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 11, 2014, 06:35:33 pm
content: Pt. 1: Overview of the outsideSo I managed to find my way in. As I am still told to stay in bed after surgery I will have to go little by little. My pictures are bad this time, please excuse. I have not much time to reshoot and edit on my main PC before my foot starts to grow bigger and bigger and turns blue.Pic 1: Front panelPic 2: One knob taken apartThe front panel (Pic 1) looks a bit like on a oscilloscope. On the left side you can dial in amplification of the returned signal and power of the sent impulses, on the right side you can preselect the speed of sound in your material and how big your DUT is. Also some suppression and offset can be set. Please don't ask what which switch or knob is used for exactly - I DON'T KNOW.The whole thing is made to withstand very rough environments. Everything is sealed with soft gum. We will see how well that worked when we open this device. You can await some beautiful engineering art in here. I can tell that by just trying to take of the cap of one knob! They are designed to be only turned when pushed down. This way they cannot be turned accidentally. The riffled surface gives good grip even with oil on your fingers (which is normally used to couple your signal into the DUT). Look how many parts go in there. Picture 2 does not even show all of them! There are two more headless screws and the bottom of the knob can only be taken off when the inner nut is taken off.But I soon found this is not the way to get into the case, so I stopped there.Pic 3: The Unipan Typ 510 is a big beastPic 4: Easily accessible calibration compartmentPicture 3 gives a hint how big that beast is. On the right side is a little compartment that holds some trimpots and a switch for calibration purposes (Pic 4). On the left side is a large button labeled "filter". No idea what that filter does filter. Maybe we will find out later.Pic 5: Backside with standoffs, mains selector and some banana jacks.The back (Picture 5) holds some large standoffs which double to hold the powercord. There is a mains voltage selector and some banana-jacks which I am not sure what they are good for. Also that big thing in the middle with the little handle. It is the magic way into the Unipan Typ 510...Pt. 2: Sneakin' in

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 11, 2014, 07:56:39 pm
content: It might be a microwave device. If you search for unipan lots of hits about microwave tech comes up. Used for detecting moisture content in paper drying process. Maybe microwaves used to do the drying too. Should be an interesting study.

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 11, 2014, 08:12:50 pm
content: Quote from: GiskardReventlov on February 11, 2014, 07:56:39 pmIt could have been, but the "Ultraschall Prüfgerat" on the front disagrees with you.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 11, 2014, 09:13:26 pm
content: Quote from: PA0PBZ on February 11, 2014, 08:12:50 pmReading the front? That's cheating! In any case, in a pinch, it still might cook food.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 12, 2014, 08:29:19 am
content: GiskardReventlov: The Unipan Typ 510 is indeed forultrasonic testing. Not enough for cooking food.Pt. 2: Sneakin' inAs I said I finally managed to find a way into the unipan Typ 510. I was able to take off the back.Pic 6: Back can be taken of as one piecePic 7: Inside of the backpanelThe Back comes off in one part easily if you find out how to get it loose (Pic 6). On the inside there is only some wiring and two big cans. I am pretty sure there are some transformators underneath, maybe a little rectifying or something under one. We will for sure look inside later. Else there is only a pin for alignment and a big-ass connector. I like how clean everything is - no grease (only one loose nut was found. Wouldn't want that in my high-voltage-supply... hmmm). And a very tidy construction by the looks of it.Pic 8: High power connector on the backpanelPic 9: Corresponding half of the High power connector in the casePictures 8 and 9 show the corresponding halves of the beefy connector. I love how all the cables and the supply stuff get out of the way by just taking it off. Brilliant construction.Pic 10: sneak peak into the chassisThere you have a very first look inside the chassis (Pic 10). Not much to see, seems like everything is extremely tidy. I am nearly sure I can take off the case if I undo the screw in the center and the single ground wire. We'll see next time!Pt. 3: What's inside the cans?

author: Towger
author_rank: Super Contributor
timestamp: February 12, 2014, 08:57:15 am
content: What is it covered in? It looks like it came from a commercial kitchen which was never visited by a health inspector...

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 12, 2014, 10:03:18 am
content: It is a mixture of old grease and lots of very tiny metalflakes! This is typical for this kind of devices. You need a couplemedium to connect your transducer to your device under test. This is typically some oil with high viscosity. This allows your signal to be better transferred into the material and back into the transducer on its return path. If you ever have been in a metal workshop you know those very tiny flakes are EVERYWHERE. You cannot get rid of them, especially if they are magnetic and especially if there is oil or grease around.Second thing is - there is a so-calledmagnetic particle inspection. This means you have to bring some low-viscosity oil with - you guessed it - ferromagnetic metal flakes onto your device under test in order to find cracks. Very common and cheap technique which often is done before ultrasonic testing: It allows to find cracks on the outside but not on the inside. If there are cracks the piece gets scrapped, else it goes to ultrasonic inspection which requires better trained personnel and pricey equipment. Remember - we are at a preassembly stage, working on less more then raw materials. Those tests are very often done on special iron based alloys that were hardened for a very special purpose right in the workshop. Hardening is a very tricky process to get right and buries lots of dangers for the workpiece, especially if the workpieces are large.So I am pretty confident this kind of grease and flake composition is what you see on the device. Ugly but ok. Remember, this thing was sold as being defective. No need to clean it before selling. Of course your normal household anti-grease formulas won't work on that kind and thickness of dirt.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 12, 2014, 04:23:15 pm
content: Pt. 3: What's inside the cans?Back from the doctor, time to up some more photos before I am too dizzy again.Pic 11: The inside of the backpanel with the cans removedPic 12: Minimal DC Supply on the mains transformerPic 13: Second transformer with capsThe backpannel carries some basic power supply stuff as anticipated (Pic 11). There is one big transformer with 2-diode-rectification and two fuses (Pic 12), which is a minimal DC supply I think. Possibly I found there why the thing would not work - on fuse is blown.Under the second can is another smaller transformer with lots of capacity (4x470µF in parallel as I think by a very quick look). Also a decent sized bleeder resistor (Pic 13).Pic 14: Spacer between the capsPic 15: folded metal but no visible seam!Attention to detail 1: The caps on the second transformer are wraped in some clear shrink wrap (I think it is), then held down by a metal strap. Inbetween them is a custom made spacer placed. No ratling possible where some manufacturers would just rely on the solderjoints (Pic. 14).Attention to detail 2: The backpanel is made of a folded sheet of metal. But you won't find any seam! It is just weldet perfectly and completely deburred (Pic 15). Never saw such perfect bent and welded sheetmetal before, no matter how expensive the unit was. This is just unbelieveable.Pic 16: A hole in a screw is always made on purposeThis is the screw I suspect to be responsible for holding the whole unit together (Pic. 16). Wonder what the hole is good for? In environments where ultra high reliably is important screws get secured this way: Shakeproof washers are no longer allowed these days in very safety-relevant situations for securing a screw for a reason! They can actually rattle loose. That's why you nowadays always find a blob of glue on there or an eyebolt. Or it is done like it was supposed in this unit: get a wire through the hole and the stretched out piece of the case and fiddle it together. The screw may rattle loose but cannot turn anyway. This is never done without a purpose. The missing wire in my unit tells me it was opened before.Pic 17: finally we're inSure enough the screw was for opening the case. After many turns the whole case slides off to the back of the unit, revealing the innards of this monster (Pic 17). Again with attention to detail: The screw cannot get lost as it is fixed in the case and cannot fall out.I haven't counted yet but there are many PCBs in there. The thing is completely filled. The boards are not too dense but every free space in the case was used. I think from now on it is going to be difficult to get it appart in a way that allows bringing it back together. But I definetely plan doing so. Just to prove I can O0Pt. 4: Investigating the inner construction

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 12, 2014, 04:43:07 pm
content: The second transformer with the capacitors - could it be a choke? I can't see any wires in the picture but if there are only 2 wires it's obvious.

author: SeanB
author_rank: Super Contributor
timestamp: February 12, 2014, 07:41:52 pm
content: If you need the locking wire I have both the tamper evident one and the regular aircraft grade. I used a lot of it over the years, and with the right tools it is easy to use, though you can get by just using a set of long nose pliers and a good set of diagonal cutters. Not fun when you have to lock 80 bolts together using a single 30m length of wire. That will take a good 2 hours to do and inspect.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 12, 2014, 08:54:21 pm
content: On the mains-transformer-and-rectifier image some of the screws look to be suffering from corrosion. Is it due to electrolysis? Or is it something else? Maybe it's a coating of some kind?I love those hand-woven wire wraps.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 13, 2014, 10:16:53 am
content: Quote from: PA0PBZ on February 12, 2014, 04:43:07 pmActually there are four wires going there, but you are right nonetheless. I was fooled since the two black wires were just a doubled ground connection. On further investigation it is a choke with the caps on both ends leading to ground. It is a Pi-configured LC Lowpass! I suspect the wires that go in there to come from the supply board in the chassis but I am not sure yet. Maybe I should follow them.Quote from: SeanB on February 12, 2014, 07:41:52 pmI am not sure yet if I will bring that thing back to life. Not sure about its resale value. If I do I will use simple wire. I think this option was only for safety reasons, not for proper sealing.Quote from: GiskardReventlov on February 12, 2014, 08:54:21 pmIf you mean the brown stuff thats all over there - that's some sort of coating, no rust. Maybe to prevent rust but more likely to fixate the nuts I guess. I actually could not find a single sign of rust or other corrosion.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 13, 2014, 11:06:27 am
content: Pt. 4: Investigating the inner constructionAs I said the Unipan Typ 510 is very convoluted on the inside. But see for yourself.Pic 18: Overview top sidePic 19: Overview left sidePic 20: Overview right sidePic 21: Overview bottom sideSo what do we have? From the top (Pic 18) you can start counting the PCBs: There are four real PCBs and one shielding board mounted vertically. Also there is some kind of can under the tube and a sheet of black metal again mounted vertically, acting as a heatsink for a single device I could not identify yet. Maybe it ist there for shielding, too? I don't know. Then there is a second can which we saw before when we took a peak inside the case: It's marked with 8kV, of course we suspect a villard cascade in there.Pictures 19 and 20 only reveal a glance on the to PCBs. But take a look at the potentiometers sticking through the top PCB but actually being mounted on the one underneath (Pic 20).Then I flipped the chassis over. And what can I say - one more PCB (Pic 21).That makes 5 PCBs plus a can for the high voltage generation , some shielding and a few parts mounted offside the PCBs. Also not to forget the parts mounted on the backpanel and all the passives direktly mounted on the switches on the front panel. Some of these switches are completely shielded, we will investigate that later.Pic 22: familiar looking Trimcaps on a switchFor now I only took a picture of some trimcaps on one of the unshielded switches (Pic 22). They look quite familiar now - saw them first in the Philips PM 2422A in my last teardown.Now back to the last mentioned board on the bottom of the device. I am confident this is the power supply board for the whole thing, regardless of the things happening on the backpanel. I did not take it out yet but took a few shots of remarkable parts and things going on there.Pic 23: transistors with cut off legs?Pic 24: nice mountingPic 25: mystery boxPic 26: many rectifying diodesPictures 23 and 24 show twoTI BD245B NPN (Datasheet)power transistors. One leg is cut off but the tab is connected beautifully. They are just wired to the high voltage can.On first glance I did not know what the box in picture 25 might be (Had not realized then this was a power supply board). Now I am confident it is a potted transformer. Next to it are what I suspect to be two full wave rectifier bridges and some big filter caps (remarkably rated 160V, Picture 26). With that voltage rating I am not sure if there is only CRT-related stuff going on on this board. I guess I will find out soon.Pic 27: multilayer constructionLast but not least this neat construction caught my eye (Pic 27). I am not sure if that was an afterthought and they could not fit in two more resistors in parallel without changing the layout too much or if they just decided to drill 4 holes into the existing traces and bodged those two upper resistors in there. Obviously, this is done very professional. Don't mind wether it is a bodge or not.By the way: The unit itself states clearly it was made in 1984. But many devices show what I think is datecodes ranging from the late seventies to 1982 for the youngest I have seen yet. Hmmm.I am still looking for more information on this or similar products made by unipan. If you have anything please let me know. If you speak Polish I would be glad if you could help me finding information. There seems to be something on some polish websites but I cannot understand itPt. 5: Power Supply PCB & High Voltage Can

author: rsjsouza
author_rank: Super Contributor
timestamp: February 13, 2014, 12:15:39 pm
content: Excellent teardown, schwarz-brot! I love the look of the woven fiberglass on the PCBs, the details of the mechanical assembly and these ELNA caps (it brings back memories when these together with Siemens and Philips caps were everywhere).What are those round devices marked with 1, 2, 3 dots under the loudspeaker? Some inductors, perhaps?

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 13, 2014, 12:52:31 pm
content: I was puzzled by these, too. The Labels say they are TR***. TR is generally used on transformers over the device, so yes, I think these are inductors of some kind. I will come to this board later, please be patient. Will take me lots of time to figure out what is doing what with no schematics on hand.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 13, 2014, 08:28:08 pm
content: Just something I noticed. Sometimes clues come from inocuous places/things.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 13, 2014, 09:03:47 pm
content: Now I see what you ment. Don't worry, this is just washed out in the picture because I had to pull up the brightnes very much as I did not get the aperture/timing right on first try. The picture was way too dark before. I can say for sure this is not corroded. I think the sheet metal is galvanized. Not sure about the screws and nuts, but they are possibly too.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 18, 2014, 05:17:37 pm
content: GiskardReventlov, you mentioned some corroded looking parts. I went back to it, and I have to admit that I am not sure wether you're right or not.There are many metal parts in there that are magnetic, therefore I am sure they are steel of some fashion, the sheet metal parts are for sure galvanized as I know that look. But many parts, especially the screws look like corroded magnesium or some weird aluminium to me. They are for sure not, as they are magnetic. They have a grey, nearly white powder on them which I would clearly identify as some oxide of the before mentioned materials, but not of anything made from steel.So I am still not sure what it is, but can say for sure that it is on every part of the case and for sure is no problem. At least I have not found a place where it might be one, yet.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 18, 2014, 05:44:22 pm
content: Maybe it's the case that the electrolysis is due to storage conditions. Maybe in a damp basement where the soil composition was the proper pH to only cause those parts to corrode. Electrolysis is caused by dissimilar materials, right? Or maybe there's a better word to describe it. Minute differences in conductivity?

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 18, 2014, 06:07:42 pm
content: Pt. 5: Power Supply PCB & High Voltage canSorry for leaving this a while. I am back with some pictures.Pic 28: A few wires to desolderPic 29: Overview bottom of power supply PCBPic 30: Mystery deviceAfter four screws and a few wires to unsolder (Pic 28) the PCB can be flipped. This is no easy task as all the wires are pretty short. Not much room moving anything. I am a bit disappointed by that as the whole thing looks like it is made for easy troubleshooting work. For example, nearly every component is placed in a fashion that allows it's value to be read without taking it out. That happens not accidentally for sure.Well, enough ranting. The bottom shows some simple traces and one more device (Pictures 29 & 30). It is a large potted block, but I have no idea what it is. No markings on it, no signs on the board, nothing. But it is nicely placed between the tubes supporting structure and the next vertically mounted PCB. Theres not more then a few milimeters room when the mystery device is in there. All constructed in the days when there were no real CAD programs and 3d-footprints and stuff. Just wow.Pic 31: High voltage can without its lidPic 32: They are serious about protection herePic 33: Cover removedNext I tried to see what's inside that remaining can. As stated before it is obviously the high voltage generation for the CRT. First I took off the lid and was a bit surprised (Pic 31). There are some parts of the circuit potted. Is that normal for the high voltage circuits in, say, TVs? I have to admit, I am a bad hobbyist - I never opened a TV beforeI then unscrewed the protective material on the side of the can (Pic 32). Underneath is only another board carrying some soldering posts (Pic 33). I decided this circuit is not interesting enough to risk to kill the device. I guess high voltage generation is done in a similar fashion in TVs and scopes, so I expect nothing new there. Especially as a good deal of the parts is potted anyway.Pic 34: high voltage stuff is pottedPic 35: one more peak insideI could not get the board out of the can because of the big fat high voltage wire coming out of the bottom of it which then goes straight to the front of the CRT. So I can give you only two more shots where I tried to get some of the details of the construction. with the board pealed out as much as possible. Besides the potted block there is one more transformer (I think it is) in there. Some big caps and a view diodes, nothing more to see (Pictures 34 to 35). Wonder how the board works in that metal can without spacers? It is SMD stuff! No, really, it is kind of. All these through hole components in there are only soldered to the tracks on the surface of the board. Is this typical for high voltage stuff? No matter if it is, I find it quite remarkable.Next I am going to take of the other PCBs, on at a time and see what's going on there. Stay tuned!Pt. 6: Signal generation, conditioning and receiving

author: SeanB
author_rank: Super Contributor
timestamp: February 18, 2014, 07:54:22 pm
content: HV is potted to prevent flashover. Always done as you can make it both smaller and do not have to worry about environmental factors like humidity causing problems.As for black Mystery block i think it is a potted choke with a large air gap, used to generate a high voltage or to couple signals without saturation. See if the ends are ferrous.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 18, 2014, 08:15:50 pm
content: @schwarz-brot, I forgot to say, when I did a search earlier on unipan, there was a link about a museum. I never checked the link but you may have something that a museum curator might like to add to the collection. And if you're intent on keeping it you may find the curator can tell you more about this unit.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 19, 2014, 09:26:48 am
content: Quote from: GiskardReventlov on February 18, 2014, 08:15:50 pmWould you mind trying to find that link again? I spent about half an hour but all that turns up is not useful to me.I sure would be glad to give the device away if I cannot bring it back to life. There is not much in there that would be worth ripping out.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: February 23, 2014, 03:36:14 pm
content: Pt. 6: Signal generation, conditioning and receiving.The generation and conditioning of the test signal is spread over two single sided PCBs and most of the front panel controls. These Boards also seem to condition the received signals before sending them off to the beam conditioning circuitry. At least this would be my guess. The boards form the sandwich on the left side of the device, consisting of the top board labelled "Z-322B", the bottom board "510.03" and a shielding layer inbetween them. I have not even tried to understand what is really going on there even though I think it would be relatively easy to reverse engineer the single PCBs. The layout is pretty clean and most parts are alligned in the same direction. But see for yourself.Pic 36: Overview of the top PCBPic 37: joint on top PCBPic 38: Top PCB flipped upThe top PCB (Pic 36) sports a speaker of yet unknown purpose. Also these three devices with dots which were asked for before. As I said I am pretty sure these are some transformers. There are four wires going in there on the ones with two and three dots. Number one seems to be a choke for only two wires going in there. Note that the potting seems to be split on most of these devices.When investigating I was puzzled what those little metal pieces on the hex-posts were good for (Pic 27). I soon found out they are actually hinges. Take out two screws on the other side and it can easily be flipped over. Beautiful! The shielding board is attached to the top PCB with three spacers (Pic 38).Pic 39: wiring actionPic 40: Shielding PCB removedPic 41: Bodged to perfectionWhen the board is flipped up you find some wiring and a few larger, shielded wires, probably coax type (Pic 39). The shielding board is easily to be removed and reveals the traces on the bottom of the top board (Pic 40). Note how the coaxes are held in place with some clamps. Again very neat construction, wherever you look. This even goes for the bodges! There are some here and there, but they are done in a very professional way. I nearly missed this one (Pic 41).Pic 42: The bottom PCBPic 43: backside of the bottom PCBWhen the top PCB is flipped up you can access the bottom PCB (Pic 42). It is pretty crowded but still the layout seems to be very clean and simplistic. And again, attention to detail. This board is singlesided, through hole construction. But all parts are soldered on the copper side of the board. There is only one possible reason to go through all that effort: All for the ease of servicing! Thanks to this upside down approach you can reach every solderjoint without ripping the boards out which would require desoldering plenty of wires.On the bottom of this board there is a large device which looks like a power resistor or a capacitor to me, a diode and a jumper wire (Pic 43). Nothing else, and none of these looks like bodged in.Pic 44: the related elements on the front panelPic 46: Big ass switch on front needs big ass can on backMost of the wires on these PCBs go off to the front panel. Picture 44 shows all related elements. The top switch "Sendeleistung" is propably to set the power of the output signal. "Anfang" und "Breite" are for setting the offset and pulse width of the output signal. The switch "Ein/ Monitor" may show the output signal in position "monitor" and the returned signal when in position "ein". Another possibility is this switch cuts of something to send it to a remote monitoring device. Not sure about that. The backside of all these knobs can be seen in Picture 45. You will notice it is pretty convoluted in there which I think is the reason for the slightly odd placement of some of the knobs.The large double layer rotary switch "Verstaerkung (dB)" on the bottom left side of the front panel is an attenuator network. I am pretty sure of this one. The input and the output coaxes go in there, nothing else. Backside view of this biggie is given in picture 46.The BNC connectors send the output signal and receive also the returned input signal. There are two possible ways to measure. You can send your signal through your DUT utilizing a transmitter probe (S) and an receiver probe (E) which are connected to the corresponding BNCs. The right switch has to be in lower position according to the symbol. The second method involves only one transceiver Probe. You rely then on the reflected signal and use your sending crystal also as receiving sensor. Then you only need the right BNC (S) and can turn off the other one with the switch.The left switch "Ein/Aus" under the screen is finally the on-off switch for the whole device. Its leads go straight to the large connector on the back. On its right is a little meter. Not sure if it is only an on/off indicator or if it is a sensing meter to show if the voltage is right for the impulses, say a loading indicator for the caps? Had a talk to a friend of mine who knew the sent impulses are between 100V and 400V DC, depending on your probe and the thickness of your DUT.Enough for today. Hope you like it this far. Next time I may propably do the rest. We will see.Pt. 7: Beam deflection circuitry

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 25, 2014, 09:49:26 pm
content: Sorry, don't know where that link is now. I recall that I had searched on a scientist's name that had designed unipan gear. Maybe something to do with polish academy of sciences.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: March 01, 2014, 05:18:59 pm
content: This is probably going to be the last part in this series for a longer time. I will finish with an overview of the last PCBs that I did not show in detail yet. I started checking for supply voltages and soon found out that there seems to be a lot of trouble on the supply PCB as most of the voltages seem to be missing. I wrote to the Institute which formed Unipan back in the days hoping they might provide me with some documentation but have no answer yet. I will give it some more time and maybe then start a massive attack on that board, but I haven't the time to give it a go right now. Of course I will then update this topic.But let us take a look at the last two PCBs now. This is :Pt. 7: Beam deflection circuitryPic 46: Overview of the PCBsPic 47: Top view of the upper PCBPic 48: Bottom view of the upper PCBPic 49: Bodge timeAt first an overview of which boards we are talking (Picture 46). I suspect these boards to be responsible for deflecting the CRTs beam according to the settings on the frontpanel and the trimpots which can be seen sticking through the top PCB. They are actually mounted on the bottom PCB.The components are again laid out relatively dense but still all alligned neatly (Pic 27). Note the cutaway for the large rotary switch mounted on the front panel. The traces are on the bottom side. Nothing else there but many wires (Pic 48) and a botched resistor (Pic 49). In picture 48 you can see this board is again mounted on these nice little hinges. Beautiful.Pic 50: Transistors and trimpotsPic 51: some capacitorsPic 52: More transistors, sharing the heatThe top PCB sports some big looking transistors typeBF 257 (Datasheet)(Pic 50). Can anyone identify the manufacturer? All around them are lots of trimpots which I guess are there for finetuning the quiescent point. In the same picture you can find a diode purposefully placed above a resistor and another wire. Spared a bridgeThen there is a funky looking capacitor (Pic 51) and some transistors clamped down with a metal bar, so they get evenly hot. Obviously they figured out they needed some temperature compensation or at least the same drift in both of these transistors (Pic 52).Pic 53: Top view of the bottom PCBPic 54: Bottom view of the bottom PCBThe bottom PCB is mostly impressive for its big and beefy parts and the potentiometers (Pic 53). And yes - these are real potentiometers, and high quality ones as well, by the looks of it. Again the bottom of the board shows just the traces and the pots (Pic 54). These potentiometers are for adjusting the beam and can be reached from the outside of the case (refer to picture 4).Pic 55: capacitive switchPic 56: beautiful wiringLast but not least again some random shots. Picture 55 shows a detail of the large rotary switch which sits in the cutout area of the PCBs. There are lots and lots of capacitors mounted directly on there, nothing else. The switch is for setting the test area ("Prüfbereich") between 10mm and 5m. I guess they determine the horizontal stretch of the screened picture with this switch.Picture 56 shows again some beautifull wiring. I can't help admiring this technique.As I said in the beginning - this is it for now. I will eventually return to this topic and and keep you updated if I finally start repairing this device. I hope you liked this series. As always I look forward to your comments, be it positive, negative or helpful in any ways (I still look for information on Unipan... and especially this device). Your comments keep me motivated.