EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: neo on July 23, 2016, 09:19:47 pm
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SO i recently bought a ballantine 1066s oscilloscope, it powers on all the switches feel nice but all i get is a little dot which i can not get to form into a line at all i tried testing a few frequency sources to no avail. My question is this why only a little dot (focus works and turns it into either a vertical line or a bigger dot) and how do i fix it. Like an idiot i bought it from a long ways off so i either make it work or i have no oscilloscope. please help
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It is either in xy mode, external time base mode or it is broken.
Can you post a picture of the front panel so that we can tell if it is in exteranl time base mode?
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forgive the delay my net is not the best
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The time base is on 20us per division,
Trigger is on channel 2 , -ve, so they are ok.
Is the beam finder button stuck on? ( can you press it down and does it release?)
Try adjusting the intensity and focus to see if they is a line but it is not looking good.
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Beam finder does work and as i said focus varies between that dot and a 2 division vertical line or 2 division blob (i am more specific on this here than on my original post though) if it is broke then the question is how to fix it because i dont have money for another one
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Try openning up the scope and look carefully around the inside. Look for any loose wires hanging off.
I got lucky with my scope, similar problems to what you have, openned it up and found 1 wire was hanging off, just plugged it back onto the connector and it was working perfectly.
If you do not find anything like that, I am affraid you will have to find the fault and fix it. Start with searching for the service manual or schematic diagram.
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about that service manual i dont have one and cant find one, give me a couple minutes to look at the guts
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i see no loose wires though i can provide pictures of the interior if you would like
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Affraid no good to me, I would need schematics to work from. Thought it might have been an easy thing with the controls. I am not that good at repair myself, I have got a Weller iron I was going to ask for help myself.
Try the repair foruum.
Or if it was an ebay sale, try asking for a refund since it does not work.
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@ neo
If you hook a probe to the Cal output do you get a vertical line?
Can you move the dot left, right and up, down?
If all that works I suspect the Sweep generator has failed.
What other equipment do you have for fault finding?
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@tautech i have a multimeter, capacitence resistance current and voltage (with a diode ester of course) and thats about it this oscilloscope is my first big piece of test equipment i don't have much in the way of test equipment come to think of it
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No problem, did you do those tests?
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i can move the dot one division by adjusting focus but thats it i hooked a test probe to everything that would accept bnc except for channel 2 out that shocked me as did external trigger not alot but enough to let you know that you've been shocked
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You should have a 1 KHz probe cal output, commonly 3 or 5V p to p that if connected to the inputs as the scope is, should display a vertical line, being as I suspect the sweep generator has failed.
The sweep is a ramp waveform, the rising voltage is implied to the horizontal plates that electrostatically deflect the electron beam across the display. Frequency of the sweep is controlled by the timebase setting.
In order to diagnose the problem you must input a known waveform and the probe cal is perfect to this.
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You should be able to move the dot around the display with the vertical and horizontal position controls.
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Also switching both CH1 and CH2 on, and switching to 'CHOP', should give you 2 separate dots.
AFAICT the only differences between the A, B, and S models is the bandwidth 15,20,25 Mhz.
Don't forget this thing contains 4 Killer Volts even when switched off.
http://lcweb2.loc.gov/master/mbrs/recording_preservation/manuals/Ballantine%2520Portable%2520Dual-Channel%2520Oscilloscope%2520Model%25201066A.pdf (http://lcweb2.loc.gov/master/mbrs/recording_preservation/manuals/Ballantine%2520Portable%2520Dual-Channel%2520Oscilloscope%2520Model%25201066A.pdf)
http://www.ebay.com/itm/BALLANTINE-MODEL-1066B-Dual-Trace-Oscilloscope-Instruction-Manual-schem-17011-/390620703232 (http://www.ebay.com/itm/BALLANTINE-MODEL-1066B-Dual-Trace-Oscilloscope-Instruction-Manual-schem-17011-/390620703232)
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two things i would do at first:
-check that the BEAM FINDER button is not stuck
-select the auto or free running trigger mode, that way you should *at least* see the dot moving left to right
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I would guess this is going to be the plates' HV which is missing, on the last photo of the ebay manual it's looks like it's +180V, which seems low for a 4KV tube to me, but there you go!
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i can move the dot one division by adjusting focus but thats it i hooked a test probe to everything that would accept bnc except for channel 2 out that shocked me as did external trigger not alot but enough to let you know that you've been shocked
That's bad news. There should be nothing capable of shocking you even a little bit on the outside of the scope.
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Good news i messaged the seller and after a brief conversation got half my money back and i get to keep the scope, i may bite the bullet but at least its a reasonable and peaceful end :phew:
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I'll choose to see this as a lesson, don't buy oscilloscope from over 700 miles away especially not ones that are dirt cheap and over 40 years old with no manual or schematics to speak of, which is obvious in hindsight but baby steps i am relatively new to this.
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Good news i messaged the seller and after a brief conversation got half my money back and i get to keep the scope
Nice one :-+
Maybe it should not be too hard to fix.
As one of the others said, sounds like the time base ramp generator. Either
1. the low voltage circuit is not generating the ramp
2. the ramp is not reaching the HV amplifier
3. the HV amplifier is not working.
In my case it was 2. the wire+connector had fallen off the pcb connector. It was near the connector but no longer plugged in. The owner had told me that the scope had been knocked over and then the screen was all blured.
Did the owner say it was working before shipping?
Since your scope was shipped, it may have been knocked. Have another look around the inside (careful not to touch the HV stuff) and see there are any wires that look like they are not plugged into anything.
Are they any components that look like they are broken or blown?
Is there anything on the back of the scope that has been knocked?
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The owner said working but i don't know whether he meant it turns on or it generates traces working. I have yet to do a thorough poke around, and it does look a little beat up. As for a replacement oscilloscope how does this one look http://www.ebay.com/itm/Hitachi-Oscilloscope-V-212-20-MHz-/221976372042?hash=item33aed2a34a:g:wjIAAOSwp5JWYd5p (http://www.ebay.com/itm/Hitachi-Oscilloscope-V-212-20-MHz-/221976372042?hash=item33aed2a34a:g:wjIAAOSwp5JWYd5p) i have the manual in pdf form complete with schematics i'm also looking at the Tektronix 2465 complete with manual if the auction doesn't go crazy
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As one of the others said, sounds like the time base ramp generator. Either
1. the low voltage circuit is not generating the ramp
2. the ramp is not reaching the HV amplifier
3. the HV amplifier is not working.
I'd say none of the above, because it effects both X and Y movements.
I wouldn't throw the scope away yet, from the photo the front panel still looks in very good condition for its age.
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As one of the others said, sounds like the time base ramp generator. Either
1. the low voltage circuit is not generating the ramp
2. the ramp is not reaching the HV amplifier
3. the HV amplifier is not working.
I'd say none of the above, because it effects both X and Y movements.
I wouldn't throw the scope away yet, from the photo the front panel still looks in very good condition for its age.
Quite.
Once this one's fixed with another you can use this one to keep the other one fixed. ;)
Don't ask how I know. :phew:
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i never said a thing about tossing the ballantine, i will keep it i just wanted an opinion and what you think would make a good (WORKING) scope since my first try appears to be a bust in all regards except as an experiment
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i never said a thing about tossing the ballantine,
I know, just making sure, you know what people are like around here, they buy non-working scopes from miles away and all kinds of things. :)
Keep looking, but be patient, I'm not very good at judging US$ values, but in the UK scope prices are dropping all the time, nearly as fast as the £.