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Unidentified oscilloscope Please help

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HighVoltageProjects

Sat Mar 09 2013, 10:39PM

Registered Member #9770 Joined: Wed Jan 23 2013, 01:42AM
Location: Wymondham, Norfolk, UK
Posts: 11

Hi I recently brought a scope from a car boot sale that I cant find any info on as I have no idea on make and model.

All I can tell you is that it is three trace and looks like some other Hitachi models but that really means nothing

I would really like to know the bandwidth as really make and model is not the issue .I have looked at buying probes but nothing seems to meet the 1Mohm 25pf it requires .Maybe I just don't know enough about scopes to tell and any info is good info as I have none
I will post some pics and any help would be great Thank you in advance

testtest

Sat Mar 09 2013, 10:52PM

Registered Member #3271 Joined: Mon Oct 04 2010, 02:29AM
Location: Canada
Posts: 159

Does reminds me of my old Hitachi.

Funny that there are no real brand markings on any of your photos. It might have been located over the crt bezel. I would suggest removing the case covers and look at the components inside. You might get a clue of the manufacturer from the markings on the pc boards and component origin such as electrolytics, semiconductor and ic markings as its sourcing.

It does look pretty complete as far as functionality is concerned. From the horz timebase its vert bandwidth might be a bit limited but OK for general use. You might want to look at eBay for a set of probes.

If you don't get an ID soon post pictures of the insides.

Have fun. Getting your first DVM and scope are always worth remembering.

Houdini0118

Sun Mar 10 2013, 12:57AM

Registered Member #8558 Joined: Thu Dec 06 2012, 11:38PM
Location: usa
Posts: 57

you not looking for 1mo probes that the scopes input impedence just get some cheap 1x/10x probes off ebay.

Mattski

Sun Mar 10 2013, 08:43AM

Registered Member #1792 Joined: Fri Oct 31 2008, 08:12PM
Location: University of California
Posts: 527

I have a 20MHz Iwatsu scope that goes to .5us/div on the timebase, or 10 cycles per division.

Yours goes to .2us/div so the bandwidth of your scope should be about 50MHz.

HighVoltageProjects

Sun Mar 10 2013, 12:02PM

Registered Member #9770 Joined: Wed Jan 23 2013, 01:42AM
Location: Wymondham, Norfolk, UK
Posts: 11

Well thanks guys I will open her up tomorrow being mothers day and all .I wasn't sure about buying cheap leads as i was unsure on the MHz , Also everything I read says not to buy cheap ones as the scope is only as good as the leads attached but to be honest I don't know how good the scope is yet .
Thanks again John

Wolfram

Sun Mar 10 2013, 02:27PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

I'm pretty certain it's a Topward, I've had a couple. You can see one in this

picture.

klugesmith

Sun Mar 10 2013, 04:00PM

Registered Member #2099 Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1714

Hi John.
Nice scope you got there. It would be silly to open it up hoping to find out the brand and model (which have little to do with the designer or maker, in these anonymous instruments). Component date codes would tell you the approximate age, but who cares?

You can accurately determine the scope's vertical bandwidth by measuring its risetime. Get a "step" signal source (such as a digital device output) with rise or fall time known to be substantially shorter than that of the scope. Contrive a suitably fast connection to the scope's BNC input. We can help with that. Perhaps make it a standard project.

I hope the following isn't insultingly basic, but you did call your acquisition a three-trace scope. (see appendix)

Step 1: Can you power it up and get flat-line traces on the screen? No need for probes -- set the trigger mode to Line or Auto, and the sweep speed around mid-range.

Then don't rush to buy probes. Get a plain old BNC cable and strip the wires at one end. Use it to explore some low voltage signal sources like a battery, a low voltage transformer, or the audio output of a sound gadget.
Before probing voltages high enough to damage the scope, get a 10x probe. (Essentially a holder for a 9 megohm series resistor, with capacitive details that can wait. See appendix.)

Good luck. Happy learning.
-Rich

appendix:
Your scope has two input channels for vertical deflection, and one for an (optional) "external" trigger source. The controls are self-explanatory to anyone with 'scope experience, such as people at boot sales. Can you find someone to teach you in person?

As someone said here , the input channel impedance is 1 megohm (in parallel with 25 pF, but that doesn't matter for now) . You can measure it with an ohmeter. That value is practically universal, and implicitly compatible with almost any ordinary "10x" probe.

Houdini0118

Sun Mar 10 2013, 05:11PM

Registered Member #8558 Joined: Thu Dec 06 2012, 11:38PM
Location: usa
Posts: 57

i dont think over voltage is that much of a problem dont use your scope on anything over 400 volts without a attenuator or something

testtest

Sun Mar 10 2013, 05:34PM

Registered Member #3271 Joined: Mon Oct 04 2010, 02:29AM
Location: Canada
Posts: 159

klugesmith wrote ...

Hi John.
Nice scope you got there. It would be silly to open it up hoping to find out the brand and model (which have little to do with the designer or maker, in these anonymous instruments). Component date codes would tell you the approximate age, but who cares?

On all my scopes (Agilent, Tek, Sony and a few nondescrips) this involves two to four screws to pop the cover off and all have markings as to model and manufacturer on the printed circuit board. Only a few minutes work. Once you have that info, searching for a service or operation manual is much easier..... also the markings on the ICs and transistors are very telling of the origin and quality of the instrument once you put them in Google.

HighVoltageProjects

Sun Mar 10 2013, 06:57PM

Registered Member #9770 Joined: Wed Jan 23 2013, 01:42AM
Location: Wymondham, Norfolk, UK
Posts: 11

Ok thanks all ,No nothing said will be insulting .I don't know much about scopes so all this is helpful .I only thought it was 3 trace as I get 3 horizontal flat lines and If I put a signal into all of the 3 channels either at the same time or on there own from the calibration or signal generator I get the same trace (if that's what its called).
I will take the top off as I Don't think it will do any harm and it may have something on/in there.
I really do appreciate all the help though guys thanks John

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