Probe for Soviet made oscilloscope - Page 1
Forum section: electronics / beginners

author: conel
author_rank: Newbie
timestamp: June 05, 2014, 01:16:47 pm
content: Hello.I bought my first oscilloscope and that`s USSR made analog oscilloscope SAGA. My model looks similar to C1-94, but there is no clear indication what model it is, except its brand.Problem is, I don't have probe for it, and I couldn't find one.Maybe someone on the forums knows how to "make" such "probe" yourself, or on which pin connect probing cable?Photo of probe socket (it was probably called DIN5 socket):According to my measurements, pins 1 and 5 are connected to each other. Then pin 3 and little metal piece (6) are connected to each other + to ground socket on right side of front panel.As it's my first oscilloscope and I'm not exactly sure what I'm doing, I didn't try to connect anything to it, because I don't want to blow this thing just yet.Any help would be really appreciated.

author: Paul Price
author_rank: Super Contributor
timestamp: June 05, 2014, 01:41:43 pm
content: turn it on a get a trace and stick a small wire into each of the ungrounded orifices of the input connector, you will find one that will give you a display and maybe an other one that is not so sensitive. The sensitive one is X1 and the other pins supplying power for a FET probe or vacuum tube low-cap probe.You can then solder some test leads or banana jacks or even a BNC connector to connect to just an ordinary scope probe that supports 30pF input capacitance.You probably need a Putin-Probe, on sale in the Crimea, you can find these in small shops in Cuba, or on USSRbay.Don't worry, you won't burn it out playing with it, it was made to survive at least three hot or cold wars.

author: katzohki
author_rank: Frequent Contributor
timestamp: June 05, 2014, 01:43:41 pm
content: 3 & 6 are Ground... so I would venture to say that 1 & 5 are signal input. Does it have a calibration output? Probably couldn't hurt it to try feeding that in.Also, to add to Paul's suggestion: Put the scope on the smallest volts/division.

author: conel
author_rank: Newbie
timestamp: June 05, 2014, 02:20:48 pm
content: I connected Atmega8 generating signal to pin 1, and ground to separate socket, and its working fine.Thanks guys.So now I have to "make" some kind of probe and figure out how to rotate lamp a bit to the right (it is of to the left, but still usable).

author: balu
author_rank: Regular Contributor
timestamp: June 05, 2014, 02:26:02 pm
content: Hi conel,Check this documenthttp://www.mikrocontroller.net/attachment/69493/Reparaturanleitung.pdf

author: balu
author_rank: Regular Contributor
timestamp: June 05, 2014, 02:28:32 pm
content: And check thishttp://www.amateurengineer.com/?p=623

author: katzohki
author_rank: Frequent Contributor
timestamp: June 05, 2014, 02:29:54 pm
content: Buy a probe. "Make" an adapter. Actually there is such a thing as DIN5 to BNC adapter, but I think you will be better off building your own rather than trying to find such an oddball.In fact, here's a guy who made an adapter for the C1-94:http://www.amateurengineer.com/?p=623

author: conel
author_rank: Newbie
timestamp: June 05, 2014, 05:32:01 pm
content: Thank you. I’ll go with building adapter, and buying a probe.I guess, that 10 USD China-made probe will be enough for such low-end scope? I don’t need this for any high frequency measures anyway.

author: Paul Price
author_rank: Super Contributor
timestamp: June 05, 2014, 06:56:38 pm
content: Many professionals , and especiallybut hams goodknown oscilloscope C1 -94(Fig. 1) . The device , with its ratherdecent specifications ,has a very small size andweight , as well as relatively lowworth. With this model CPA -Dhu gained popularity among spe -ists involved in mobilerepair of various electronic tech-nicknames that do not require a very broadbaseband input signals , anddifferences of the two channels for simultaneousmeasurements. Currently, the ex-pluatatsii is sufficientlylarge number of oscilloscopes.In this regard, this article pre-assigned to specialists whoit became necessary to repair and on-the-construction oscilloscope C1 -94 . os-lograf has the usual devices forblock diagram of this class(Fig. 2) . It contains a vertical channeldeviation in ( CWE) , horizontal channeltal deviation ( CLC ) , a calibratortorr , the electron beam with the indicatorhigh-voltage power supply andlow-voltage power supply .CEP consists of a switchableinput divider , pre-amplifier , delay lines and tip -of the amplifier. It is designed for amplificationtion signal in the frequency range0 ... 10 MHz to the level required forproduce a given coefficientvertical deflection (10 mV / div ...5 V / div in 1-2-5 sequence ) with minimumamplitude- frequency and phase- frequencygovernmental distortions.CLC includes an amplifier syn-synchronization , trigger synchronizationthe startup , sweep generator , the schememu locking and power sweep.It is intended to provide any -linear deflection of the beam with a given co-coefficient sweep from 0.1 ms / divto 50 ms / div in 1-2-5 sequence .Calibrator generates a signalfor calibration amplitudeand time.Node electron beam indicatortorus consists of an electron beamtube (CRT ) , CRT and power supply circuitsillumination scheme .Low-voltage power - designedchen to supply all functionaldevice voltages 24 V and q 12 V.Consider working on the oscilloscopelevel concept (Fig. 3) .Analyzed through the input signalSH1 connector and push button switchB1 -1 ( "Open / Closed entrance ") post -Paet on input switchable Delhi -tor elements for R3 ... R6, R11, C2, C4 ...C8. Scheme providing input divider -a constancy of the input impedanceregardless of the position switchesthe Tell vertical sensitivity B1(.V / DIV . "). capacitors dividerprovide frequency compensationdivider in the whole band .The output of the divider analyzed signalnal input to preliminaryCWE amplifier ( unit U1 ) . on the fieldtransistor T1 -U1 collected source-repeater for AC inputsignal. DC this cascadecad ensures symmetry Desktopmode for subsequent amplification stagestributor . Divider resistors R1- U1 ,R5- U1 provides input resistancetion amplifier equal to 1M . diodeU1 and D1- D2 zener -U1 - providingare input overload protection .two-stage pre-amplifier made ??with transistors T2

author: katzohki
author_rank: Frequent Contributor
timestamp: June 05, 2014, 07:03:36 pm
content: Yes you can use a cheap probe. There should be some reviews or chat regarding cheap ebay probes somewhere around on this site.Suggestion: Add a little shielding (aluminum foil or better) to your adapter when you build it.

author: DmitryL
author_rank: Regular Contributor
timestamp: June 05, 2014, 09:26:23 pm
content: Quote from: conel on June 05, 2014, 01:16:47 pmA long time ago I had a similar scope, but with an ordinary BNC connector.I would recommend you to open the scope (nothing to be afraid of there) and check if you can fit a normal 50Ohm BNC there. The connector should have just 2 wires, one of them is connected to the scope's ground.AFAIK this scope has 10Mhz bandwith, so that any lousy probe will do.

author: Paul Price
author_rank: Super Contributor
timestamp: June 05, 2014, 11:52:59 pm
content: No, any probe will not do.If your probe is a 10x probe there needs to be compensation adjustment calibration or the frequency response of the scope(even though it is limited to -3db at 10mHz) will show a incorrect/distorted of waveform/amplitude display of any signal component over a few hundred cycles.