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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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15th May 2018, 3:24 pm | #21 | |
Retired Dormant Member
Join Date: May 2018
Location: Aalborg, Denmark
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Re: Vintage u4313 multimeter
Quote:
I have changed the internal battery with the new varta and.unfortunately it is not that simple but I did not expect it to work so I'm.not too disappointed. I also sprayed all the contacts with contact spray pushed them up and down and turned the main button round. No luck. Could anybody give me an idea what the next step would be and how they themselves would proceed to trouble shoot the multimeter in leaman terms as I am an amature. I have the heart and the gear to fix it (soldering iron, led solder, a resistor kit (with all sorts of different resistors at different values, a capacitor kit (also many different values). I think my problem is I don't really understand the Russian values on the components or else I'm pretty sure I could go in and replace the capacitors and resistors one by one (I'm pretty confident with the amount of space there is that I could tackle this). I found this website that offers the schematics http://lodamurs.blogspot.dk/2014/05/...-1969.html?m=1 |
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15th May 2018, 3:34 pm | #22 | ||||
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Re: Vintage u4313 multimeter
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15th May 2018, 4:41 pm | #23 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
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Re: Vintage u4313 multimeter
My usual way for testing a voltage chain in such a meter is to set the switch on the meter to the lowest voltage range and connect a modern meter set to ohms to the positive lead of the meter under test and with the other lead fins the switch contact that reads zero ohms and then work round all the resistors that are selected by the switch.
The readings should increase in a sequence if they are OK. The same applies to the amps ranges. If the meter still does not work it will be the switch. |
15th May 2018, 5:28 pm | #24 |
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Re: Vintage u4313 multimeter
Excellent I will try this tonight if I can find the time. Have a job interview tomorrow
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16th May 2018, 9:32 am | #25 |
Heptode
Join Date: Jun 2010
Location: Zurich, Switzerland
Posts: 538
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Re: Vintage u4313 multimeter
Hi Dred,
I`m sorry for my link-it was a DMM-version of that- so is it if I didn`t checked... Please find in attachment a German manual version of C-4313, I think that is possible more understable as on your link. BTW, from your link: R1,R2=Shunt_R3--R13=wire wound (or "katushka" means coil too) _R17--R37=Resistor and so on. If you has problems to read some data of components: please post a photo over that -may be can I help in "dechipher" or somebody others too. Be successfull, Karl |
16th May 2018, 7:46 pm | #26 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,346
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Re: Vintage u4313 multimeter
A quick look at the circuit suggests to me that if the 3V range and the 30v range are working, but not the 15v range, it is a switch problem.The first choice resistor (R22) would stop ALL the higher voltage ranges above 15v as well.
Les. |
18th May 2018, 9:43 am | #27 | |
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Re: Vintage u4313 multimeter
Quote:
It's 1.5v, 3v and 7v that works the rest does not. It could be the switch your right but I might have a suspicious culprit. I will take some pictures in a minute. Some resistors looks suspicious. |
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18th May 2018, 9:44 am | #28 |
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Re: Vintage u4313 multimeter
Hi guys,
After visually inspecting the circuit again as I did not have much time to test things I started to notice something that looks a little odd with some resistors. It might just be me but none of the other resistors look like this. Here are the pictures. What do you fellahs think? Kind regards and thank you ****************/hvzTty ****************/bBrK0d ****************/eBdMDy ****************/i3tXLd ****************/kKmK0d |
18th May 2018, 10:05 am | #29 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
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Re: Vintage u4313 multimeter
Try getting a bit of that brown residue off with a scalpel or small screwdriver. if it flakes off then it is just residue from the original flux cleaner used in the factory. No action required!
Dave |
18th May 2018, 11:22 am | #30 |
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Re: Vintage u4313 multimeter
Ok, so I tried that and it looks like you are correct. It just flaked off.
Damn I thought I was on to something there. I took the hole switch off the main Bakelite board and cleaned it sprayed it with product. I also tightened the screws so as the contact would be better but still it's only working at the same voltages. So I guess something in it has broken. I'll have to see if I can work something else out then. If I was not able to fix it myself. Does anybody know what someone would ask to take a look at such an object? Today my mother's mother died, she was a good women, battled alzeimers for years. At the end she thought I was my father. She worked back in the war in northern Ireland in a converted factory that made canned food to shells for the army. Take care all and enjoy all the time you have. Life is precious. Kind regards, Peter. |
18th May 2018, 1:47 pm | #31 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
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Re: Vintage u4313 multimeter
Sorry to hear that Peter. I found out the other day that my great-grandfather fell on the first day of the Somme offensive in WWI, and is one of the 'no known grave' lads, so is now part of the landscape. Life is definitely precious- although i met an artist a few years ago who had a collection of war memorabilia, including some hand grenades. He had found most of them on old battlefields and told me he had dismantled and hollowed them out himself.
In England we now have the phenomenon of the 'repair cafe' where people bring things in to be fixed, or to learn 'how to'. I wonder if you have these? I believe an electrician would have a lot of the expertise on your meter, but persuading him to have a look might not be easy. It would not be economic for him unless he was a friend/enthusiast.. Dave |
18th May 2018, 5:35 pm | #32 |
Dekatron
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Location: Colchester, Essex, UK.
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Re: Vintage u4313 multimeter
Correct me if i'm wrong (anyone) but we are now fairly certain that Resistor 22 (R22) is likely to be at fault (or loose connection), and is in the book as 28.72 kilohm..?
This value could be approximated very well by putting 30kilohm/680kilohm in parallel, or 33kilohm/220kilohm in parallel. |
18th May 2018, 8:51 pm | #33 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,346
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Re: Vintage u4313 multimeter
Dred, if you re-read my last message, you will see that both The Philpot and I agree you should check R22 now. Regarding your photos, they look like normal resistors to me (probably high stability) and perfectly suitable. Often wire would "coil like" resistors are used in test meters, but either sort is OK if the resistance values are correct.
Les. |
18th May 2018, 9:55 pm | #34 |
Heptode
Join Date: Jun 2010
Location: Zurich, Switzerland
Posts: 538
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Re: Vintage u4313 multimeter
Hi all,
Most "coil like" resistors have usually tolerances of 0,25-0,5% (even if there are 80-100 years old) and the "normal" precisions resistors only i.e. 1% or 2%_also better not to substitut it if ther works properly. Regards, Karl |
19th May 2018, 12:51 am | #35 |
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Re: Vintage u4313 multimeter
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19th May 2018, 5:43 am | #36 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
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Re: Vintage u4313 multimeter
Sometimes with electronic circuits like your meter it helps to go through the circuit with another meter, with the meter set on continuity/diode test, this is called buzzing out, as the meter buzzes when you have a connection.
So in short, you get a schematic and work your way through the circuit from one end to the other, testing each line on the schematic/connection in your meter. You will have to switch your good meter to ohms when you come to a resistor. I hope that makes sense. One other thing, it might be a good idea to learn a little about using a meter to check voltage, current and resistance. V and R are pretty straight forward (testing is done in parallel), but testing I (current) is different. to tests amps the meter has to be in series. This will be hard to understand at first. An example, when I got my first meter I tried to measure amps by putting each test lead on a lorry battery, there was a big bang, sparks flew and I melted the meter leads, so don't try this yourself, though it is a good lesson how not to measure current. I might be able to help with resistors, if your happy to pay postage to Denmark, shouldn't be much. Send me a PM with your address, and I'll bung one in the post. Andy.
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26th May 2018, 6:10 pm | #37 |
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Re: Vintage u4313 multimeter
Hi Andy,
Sorry for the late reply, I would love to get the help. I'd definitely pay the delivery no problem at all! I have not had the time to go further with the multimeter but I'd really like.to get it fixed. Please let me know, Peter. |