oscilloscope image partial collapse

[Mike Hooker]

have an old heathkit io-10 auto ignition oscilloscope. from the center to the right side, the image is collapsed to the center.. a trace will only go from the left to the center, then its gone. you can see the right side image is collapsed in a verticle line, as its more intense . the trace from left to center is fine. it has vacuum tubes. all the tubes have heater glow. there are 2 pair of the same tubes, i swapped the positions to see if the problem moved. it didnt. i have a schematic pdf, not sure how to attach it. id like to get it going, but if its the crt, its pointless. where to from here? thanks

[Phil Allison]

mhoo...@gmail.com wrote:
===========================

>
> have an old heathkit io-10 auto ignition oscilloscope. from the center to the right side,
> the image is collapsed to the center.. a trace will only go from the left to the center,
> then its gone. you can see the right side image is collapsed in a verticle line, as its more intense .
> the trace from left to center is fine. it has vacuum tubes. all the tubes have heater glow.
> there are 2 pair of the same tubes, i swapped the positions to see if the problem moved.
> it didnt. i have a schematic pdf, not sure how to attach it.

** Schem:

https://elektrotanya.com/heathkit_io-10_oscilloscope_sch.pdf/download.html#dl

Try checking all the resistors in the horizontal circuits - after the scope has been off for 15 mins.
One might have gone high or open.



..... Phil

[whit3rd]

On Tuesday, November 2, 2021 at 7:30:43 PM UTC-7, mhoo...@gmail.com wrote:
> have an old heathkit io-10 auto ignition oscilloscope. from the center to the right side, the image is collapsed to the center..

If I'm reading the schematic right, there's two tubes that do the horizontal drive, V5 (2BS8) and V6 (12BH7)
as well as a pair of pullup resistors, R50 and R48, each 22k ohms, 2W. Start checking those.

[Michael Terrell]

On Tuesday, November 2, 2021 at 10:30:43 PM UTC-4, mhoo...@gmail.com wrote:
> have an old Heathkit IO-10 auto ignition oscilloscope. from the center to the right side, the image is collapsed to the center.. a trace will only go from the left to the center, then its gone. you can see the right side image is collapsed in a vertical line, as its more intense . the trace from left to center is fine. it has vacuum tubes. all the tubes have heater glow. there are 2 pair of the same tubes, i swapped the positions to see if the problem moved. It didn't. I have a schematic pdf, not sure how to attach it. id like to get it going, but if its the crt, its pointless. where to from here? thanks

Why do you call this an Auto Ignition Oscilloscope? It is just a typical hobby grade scope from 1960. A manual is on the BAMA site.
This is not a binaries newsgroup, so it doesn't accept attachments.
Check the plate voltage on both halves of the Horizontal driver tube. It looks like pin 10 of the CRT is the right side deflection plate.

[Michael Terrell]

On Tuesday, November 2, 2021 at 10:30:43 PM UTC-4, mhoo...@gmail.com wrote:

> have an old heathkit io-10 auto ignition oscilloscope. from the center to the right side, the image is collapsed to the center.. a trace will only go from the left to the center, then its gone. you can see the right side image is collapsed in a vertical line, as its more intense . the trace from left to center is fine. it has vacuum tubes. all the tubes have heater glow. there are 2 pair of the same tubes, i swapped the positions to see if the problem moved. it didnt. i have a schematic pdf, not sure how to attach it. id like to get it going, but if its the crt, its pointless. where to from here? thanks

The Heathkit IO-20 was an Ignition Analyzer. It used a 12AX7 for the Horizontal drive. The plate resistors are 470K They are fed from a 350 VDC source and the CRT is a common 5UP1. It came with the clip on probe for the spark plug wire.

[Phil Allison]

terrell....@gmail.com wrote:
======================

mhoo...@gmail.com wrote:
>
> > have an old Heathkit IO-10 auto ignition oscilloscope.

** You sure about that model number ?

> Why do you call this an Auto Ignition Oscilloscope?

** He does't know what it is.

> It is just a typical hobby grade scope from 1960.

** Think it is a lot better than " hobby grade".

Being fully calibrated, DC coupled with mag shielded CRT and regulated HT rails put in the " service / lab" category.
Sure, 200kHz vertical BW is not great but still very usable for most service jobs and for students doing science / engineering classes.

https://www.radiomuseum.org/r/heath_oscilloscope_io_10.html


...... Phil

[Michael Terrell]

On Wednesday, November 3, 2021 at 5:12:46 PM UTC-4, palli...@gmail.com wrote:

> terrell....@gmail.com wrote:
>
> Being fully calibrated, DC coupled with mag shielded CRT and regulated HT rails put in the " service / lab" category.
> Sure, 200kHz vertical BW is not great but still very usable for most service jobs and for students doing science / engineering classes.
>
> https://www.radiomuseum.org/r/heath_oscilloscope_io_10.html

I considered anything under 5 MHz to be hobby grade, since I worked in video. My current scope is a Tektronix 2465A I have two of the 2465 as well. I also have two of the Tektronix P6201 900MHz FET Probe 010-6201-00 to xamine crystal oscillators and tuned circuits, with minimal loading.

[Mike Hooker]

the 470k resistors are good, and i have the 350v at the rail. still stumped.

[ohg...@gmail.com]

Check R39, 40, 48, 50 all 22K each and check R45 and 47, 100 ohms each. The 12BH7 could be bad.

[Mike Hooker]

i checked every resistor, all check good. i checked the pots, all good. i checked the voltage to a and b terminals on the crt, close to whats listed on the schematic. whats makes this different than a bench scope is it has no internal trigger. it is only triggered externally by an inductive pick up. same for the vertical , another pick up. one problem is i dont know how to induce anything to get it do do something on the bench other than a dot. however, if i turn it on, you can see the dot dive bomb to the right, and then come back from right to center. seems to me that indicates the crt is working ok. i posted a video on youtube.

https://youtu.be/be-Nae-sIYQ

still , when hooked to an 8 cyl engine, i get a normal image from left to center. from center to right it appears to be collapsed or squished toward the center. where the pattern ends at the center, the line is fairly thick and intense, like a partial collapse of a cga crt.monitor. thanks for any input.

[Phil Allison]

mhoo...@gmail.com wrote:

=======================

** Why did you tell us you had an IO-10 ???

> > > > > have an old heathkit io-10 auto ignition oscilloscope.

.... Phil

[Mike Hooker]

it was either a typo or lack of sleep. not from this problem though.
sorry bout that

[Phil Allison]

mhoo...@gmail.com wrote:
=======================
>
> > ** Why did you tell us you had an IO-10 ???
> > > > > > > have an old heathkit io-10 auto ignition oscilloscope.
> > ..

> it was either a typo or lack of sleep. not from this problem though.
> sorry bout that
>

** Start again - the io-20 is a COMPLETELY different animal !!!

If all the tubes are OK and the voltage too - not much is left but the CRT.

Two possibilities:

1. Because of being used around cars, it is likely to have fallen onto a hard surface once or twice.

2. The steel case is magnetised - deflecting the trace.

See if removing the cover makes a difference.

BTW I could not find any internal pic on the net.



... Phil

[Mike Hooker]

i considered it may have been dropped. did you look at the video? im thinking if one of the defectors was damaged, the trace wouldnt move the way it does when it starts up, but maybe im off on that.

[Phil Allison]

mhoo...@gmail.com wrote:
=====================

>
> > If all the tubes are OK and the voltage too - not much is left but the CRT.
> >
> > Two possibilities:
> >
> > 1. Because of being used around cars, it is likely to have fallen onto a hard surface once or twice.
> >
> > 2. The steel case is magnetised - deflecting the trace.
> >
> > See if removing the cover makes a difference.
> >
>

> i considered it may have been dropped. did you look at the video?
> im thinking if one of the defectors was damaged,
> the trace wouldnt move the way it does when it starts up, but maybe im off on that.
>

** I see nothing unusual for a tube scope start up in your vid.

What you claimed in you OP and now is false.
The dot quickly centers then moves off to the left slowly.
Perfect.


..... Phil

[Michael Terrell]

On Friday, November 5, 2021 at 11:19:45 PM UTC-4, palli...@gmail.com wrote:

> mhoo...@gmail.com wrote:
> =======================
> >
> > > ** Why did you tell us you had an IO-10 ???
> > > > > > > > have an old heathkit io-10 auto ignition oscilloscope.
> > > ..
> > it was either a typo or lack of sleep. not from this problem though.
> > sorry bout that
> >
> ** Start again - the io-20 is a COMPLETELY different animal !!!
>
> If all the tubes are OK and the voltage too - not much is left but the CRT.
>
> Two possibilities:
>
> 1. Because of being used around cars, it is likely to have fallen onto a hard surface once or twice.
>

> 2. The steel case is magnetized - deflecting the trace.

>
> See if removing the cover makes a difference.
>
> BTW I could not find any internal pic on the net.

Heathkit used aluminum for most of their cabinets.
The CRT has a MuMetal shield.

Do you have a schematic and a real oscilloscope?
http://www.rsp-italy.it/Electronics/Kits/_contents/Heathkit/Kits/Heathkit%20IO-20%20ignition%20analyzer.pdf

I see a NE2 neon and a diode used in previous stages that could affect linearity, but I don't have a parts list. There is a pot off the Neon lap marked 'Right Adjust'.

Fair Radio still has some unused 5UP1 CRTs
https://fairradio.com/product/5up1/

There is currently another IO-20 on Ebay, less the probes.
https://www.ebay.com/itm/174516063489

[Phil Allison]

terrell....@gmail.com wrote:
=========================

> palli...@gmail.com wrote:
>
> > ** Start again - the io-20 is a COMPLETELY different animal !!!
> >
> > If all the tubes are OK and the voltage too - not much is left but the CRT.
> >
> > Two possibilities:
> >
> > 1. Because of being used around cars, it is likely to have fallen onto a hard surface once or twice.
> >
> > 2. The steel case is magnetized - deflecting the trace.
> >
> > See if removing the cover makes a difference.
> >
> > BTW I could not find any internal pic on the net.
>
> Heathkit used aluminum for most of their cabinets.

** So what ? This one may not be part of that "most".
CRT scopes with Aluminium cases are rare as hell.

> The CRT has a MuMetal shield.

** How do you know that ?
Another inspired guess ?

> Do you have a schematic and a real oscilloscope?

** Huh ?

> I see a NE2 neon and a diode used in previous stages that could affect linearity, but I don't have a parts list.

** The OP is clueless and posting contradictory, total nonsense.
So are you.


..... Phil

[Michael Terrell]

On Saturday, November 6, 2021 at 6:19:09 PM UTC-4, palli...@gmail.com wrote:

> Michael Terrell wrote:
> =========================
> > palli...@gmail.com wrote:
> >
> > > ** Start again - the io-20 is a COMPLETELY different animal !!!
> > >
> > > If all the tubes are OK and the voltage too - not much is left but the CRT.
> > >
> > > Two possibilities:
> > >
> > > 1. Because of being used around cars, it is likely to have fallen onto a hard surface once or twice.
> > >
> > > 2. The steel case is magnetized - deflecting the trace.
> > >
> > > See if removing the cover makes a difference.
> > >
> > > BTW I could not find any internal pic on the net.
> >
> > Heathkit used aluminum for most of their cabinets.
> ** So what ? This one may not be part of that "most".
> CRT scopes with Aluminium cases are rare as hell.

Maybe in Oz. HP and Tektronix used a lot of aluminum for their oscilloscope cabinets. Those aren't rare, among engineers or real techs.

> > The CRT has a MuMetal shield.

> ** How do you know that ?

From the photos that I linked to.

> Another inspired guess ?
> > Do you have a schematic and a real oscilloscope?
> ** Huh ?
> > I see a NE2 neon and a diode used in previous stages that could affect linearity, but I don't have a parts list.
> ** The OP is clueless and posting contradictory, total nonsense.
> So are you.
>

Sigh, you are the queen of posting nonsense.

Look at the photos in the Ebay link that I posted and see inside the IO-20 for yourself. I've repaired a lot of Heathkit equipment, and most of it used aluminum, except for some stereo equipment. They sold wood cabinets to cover a bare steel chassis, or you could build them into custom cabinets.

I built my first Heathkit about 55 years ago. I built dozens for myself, and others.

I also used a Heathkit color bar generator to transmit a color station ID from a black and white TV station. I genlocked it to our master Sync Generator, then used the monochrome video keyer to add color to a B&W 35mm slide. The information was displayed on the AFRTS page of the US DOD website for about a decade, before they purged all the shared emails.

The other links included a schematic for the OP and a source for a new CRT, if needed.

A working scope is quite handy when repairing an ailing scope.

[Phil Allison]

terrell....@gmail.com wrote:
======================

> > >
> > > > 1. Because of being used around cars, it is likely to have fallen onto a hard surface once or twice.
> > > >
> > > > 2. The steel case is magnetized - deflecting the trace.
> > > >
> > > > See if removing the cover makes a difference.
> > > >
> > > > BTW I could not find any internal pic on the net.
> > >
> > > Heathkit used aluminum for most of their cabinets.
>
> > ** So what ? This one may not be part of that "most".
> > CRT scopes with Aluminium cases are rare as hell.

> Maybe in Oz. HP and Tektronix

** Sure, Heathkit = Tek

Who fucking knew ..................

> A working scope is quite handy when repairing an ailing scope.

** The fuckwit OP's scope is NOT ailing in the way he claimed.

Did you miss his U-tube ?

Vid worth a million false words.



......... Phil

[Michael Terrell]

On Sunday, November 7, 2021 at 2:45:40 AM UTC-5, palli...@gmail.com wrote:
>
> ** Sure, Heathkit = Tek

In the case of using aluminum cabinets, yes they are.

> Who fucking knew ..................

Obviously, not you.

Your ignorance is showing again. The only steel cased scope I ever knowingly owned was an RCA. It was so old they called it an oscillograph. I've seen the Philco and Sylvania versions of the 3" WWII military scopes that were crammed into tiny steel boxes. I wouldn't even use one for audio work. They sat on a shelf at TV shops for decades because no one would use them.

Heathkit used aluminum, because they could produce their cabinets in house with simpler machine tools. Just because you are ignorant doesn't change any facts. Heathkit also had to consider shipping costs, since hey sold to hobbyists and repair shops where their only advantage over other kit suppliers was maybe a dollar or two. Therefore, they were more compact and lighter than failed companies like EICO. My first scope was an EICO 460 that was given to me because the CRT filament winding was shorted to the core. It was twice as heavy as a similar Heathkit, and not as well designed.

Heathkit got into electronic kits after WWII when there were millions of pounds of military grade components being sold for pennies on the pound. New CRTs were well under a dollar, so the designed a scope from what they could get.

Their prior products included a small, single engine airplane and furniture kits. They also sold electric organ kits, based on commercial products where you coukld save 1/3 to 1/2 overt the retail price by assembling the kit. A far cry from Dick Smith in OZ.

Take your meds and stop acting like a six year old. You can be a decent guy at times, but every time someone brings up something that you don't know about, you go nuts.

[Phil Allison]

terrell....@gmail.com wrote:
===================

> >
> > ** Sure, Heathkit = Tek
>
> In the case of using aluminum cabinets, yes they are.

** Childish drivel.

> > Who fucking knew ..................
>
> Obviously, not you.

** Pure idiocy.

> Your ignorance is showing again.

** No it isn't.

> The only steel cased scope I ever knowingly owned was an RCA.

** Poor diddums - could not afford a good, steel case one ......

FYI: Steel has both strength & magnetic qualities that are an advantage with CRT scopes.

> Heathkit used aluminum, because they could produce their cabinets in house with simpler machine tools.

** Yep - steel is way better but a bit harder to work.

> Just because you are ignorant doesn't change any facts.

** ROTFL - this jerkoff knows no bounds.

>
> Take your meds and stop acting like a six year old.

** FFS this just gets funnier and funnier !!!!

> You can be a decent guy at times,

** Shame that cannot be ever said about a bullshitting, Septic asshole like you.

Drop dead.

[Michael Terrell]

On Sunday, November 7, 2021 at 3:21:43 PM UTC-5, palli...@gmail.com wrote:
>
> Drop dead.

You and Sloman make all Australians look like fools.

[Mike Hooker]

i got the scope working. it was a combination of two things i believe. it doesnt have an internal trigger, i was triggering it with a d cell battery. that would give me a brief trace, enough to see it wasnt full screen. i found an open 470k resistor for a horizontal drive tube and replaced it. after replacing it, triggering it with the battery, the trace line looked full screen. i was happy, and took it from from where i work ( a railroad) to test on my truck. when i did, i got nothing. i m like WTF? after beating the internet bushes, i found the assembly manual for the unit. it was gold. it showed how to troubleshoot it using a jumper to generate a constant trace line, and another jumper to get vertical defection. it also had some scope patterns at various tube pins. after going over it, i was missing a 220 v waveform . i found a thin solid core wire from the 340V rail to a lug on a horizonal tube detached. didnt even know it was there .it was buried, hard to see, and right up against lug, but broken off. probably broke off when i brought it home. i might have compromised it replacing the open resistor, one end was on the same lug. there was also a helpul video on youtube about how defection place on a crt work. i learned a lot. i never repaired anything tube, or crt's with deflection plates, only yokes. anyway, a few people here gave good advice , one guy was a total dick, as he usually is here. thanks to all who helped.

[Phil Allison]

mhoo...@gmail.com wrote:
====================

>
> i got the scope working. it was a combination of two things i believe.
> it doesnt have an internal trigger, i was triggering it with a d cell battery.
> that would give me a brief trace, enough to see it wasnt full screen.
> i found an open 470k resistor for a horizontal drive tube and replaced it.
> after replacing it, triggering it with the battery, the trace line looked full screen.

** I posted this advice over 3 weeks ago !!

" Try checking all the resistors in the horizontal circuits - after the scope has been off for 15 mins.
One might have gone high or open. "

Seems the cockhead OP * finally* took note of it.
---------------------------------------------------------------------------------

> never repaired anything tube, or crt's with deflection plates, only yokes.

** It that a yoke ?

> anyway, a few people here gave good advice , one guy was a total dick,

** Yeah - Terrell is a complete asshole.


..... Phil

[Peter W.]

....one guy was a total dick, as he usually is here. thanks to all who helped.

That would be the Drongo from Down Under.

Peter Wieck
Melrose Park, PA

[Phil Allison]

Peter Wanker = rabid lunatic wrote:
----------------------------------------------------

> ....one guy was a total dick, as he usually is here. thanks to all who helped.
>
> That would be the Drongo from Down Under.
>

** ROTFLMAO !!

The OP is clueless, utter moron.
So an instant pal for Peter Wanker.

[legg]

Good to hear this.

happy scoping.

RL