Heathkit 10-10 Oscilloscope repair/usage

[bd139]

Yeah it’s shit and you’ll replace it if something better comes along but there’s still mileage in it which is the point.

[oldway]

There is no mileage in such an old oscilloscope anymore...It is dead...it has nothing to do with modern technology.

If you want to learn electronic, you need basic decent modern test equipment....Not the least state of the art, but some decent equipment...And this shit oscilloscope was not even the state of the art in the years 60...It was a WWII technology....

It has helped a lot of beginners in the years 60, I agree....But this is more than 50 years ago....

[bd139]

Some of us like the smell of shit

[Cyberdragon]

There's no arguing the scope is crap, it's a Heathkit, but just because it's useless for your line of work doesn't mean it's useless to everyone. There are several youtubers who show how to use these types of un-triggered scopes, you just have to know how to fiddle. If you are an inexperienced fiddler who is  spoiled by auto-triggering, well tough bananas. I've personally diagnosed an odd distorting transistor with a bad junction in an old Hi-Fi set with a vacuum tube sig-gen and a manual trigger tube scope. Just because you have lost touch with the McGyvver ways of using the bare minimum tools to diagnose a problem, doesn't mean it's impossible.

Not saying anyone should ever use this as a main scope, but yes, it is possible to teach someone how to use a scope with a tube un-triggered scope. It is even possible to use it for audio work, you don't need a triggered scope for basic audio. P.S. You said a BEM 003? You do realize that there really isn't much difference in actual functionality other than that seems to have auto-trigger and maybe a few more tubes. Sure, it's higher quality, but to a beginner, that probably doesn't matter, it'll last them until they get a new one.

[bd139]

Yep. The best scope is the one you have that works.

My old Heathkit scope was used to repair its successor successfully. No signal on either channel. I injected the output of a 555 astable into the input BNC and used the heath scope to trace it out. Eventually found a dry joint after the channel switch. Bingo it paid for itself. That scope was used to repair my old 465B and so forth.

Also the old tube scopes are virtually impossible to blow the front end up on.

[oldway]

If you want to waste your time with an oscilloscope launched on the market in 1956, which has only one channel, with a bandwidth of barely 200Khz, with a non-triggered/recurrent sweep and an uncalibrated vertical input, this is your right.
The video shows that the time base has not even a basic linearity.... 

It was perhaps valid in the 60s, but not anymore.

If you are not able to understand this, I think I no longer have to waste my time answering in this topic.

Dave has shown that decent WORKING 2 channels 20Mhz modern CRT oscilloscopes are easily found for $ 50 or less.

So, buying a FAULTY dinausore from 1956 to use it in 2017, it sounds like pure insanity. 

I can understand that it can be purchased for collecting, but not for use in learning electronics.

[med6753]

If you want to waste your time with an oscilloscope launched on the market in 1956, which has only one channel, with a bandwidth of barely 200Khz, with a non-triggered/recurrent sweep and an uncalibrated vertical input, this is your right.
The video shows that the time base has not even a basic linearity.... 

It was perhaps valid in the 60s, but not anymore.

If you are not able to understand this, I think I no longer have to waste my time answering in this topic.

Dave has shown that decent WORKING 2 channels 20Mhz modern CRT oscilloscopes are easily found for $ 50 or less.

So, buying a FAULTY dinausore from 1956 to use it in 2017, it sounds like pure insanity. 

I can understand that it can be purchased for collecting, but not for use in learning electronics.

If you want to continue to spread the hate at least get your facts straight. The Heath IO-10 has a bandwidth +2 to -5db from 2Hz to 5Mhz. Not 200Khz. It was specifically designed to service color TV's and the 3.58Mhz colorburst signal. And it does have good linearity if everything is working correctly. Is it old and out dated? Agreed. But you can still learn from it. I certainly did. 

[oldway]

bandwith of 200Khz, not 5Mhz...

http://tubularelectronics.com/Heath_Manual_Collection/Heath_Manuals_IO-IP/IO-10/IO-10.pdf

NB: nonsense is not hate....even if I would spread hate against a crap Heathkit IO-10 from 1956, what's the matter with this ?

[med6753]

I stand corrected. I confused the O-10 with the IO-10. They are totally different. Yes, 200KHz bandwidth.

But it still could be a tool to learn how to design directly coupled (DC) vacuum tube amplifiers.

[oldway]

I stand corrected. I confused the O-10 with the IO-10. They are totally different. Yes, 200KHz bandwidth.

But it still could be a tool to learn how to design directly coupled (DC) vacuum tube amplifiers.

Your avatar's picture is a 2465B Tektronix, with a bandwidth of 400MHz, sensitivity of 2 mV at 400MHz, and risetime on all channels of 0.875 ns.
And you are saying that a beginner can use a FAULTY Heathkit IO-10 of 200Khz bandwith....
You are kidding ?
Or you are hating beginners? 

[med6753]

I stand corrected. I confused the O-10 with the IO-10. They are totally different. Yes, 200KHz bandwidth.

But it still could be a tool to learn how to design directly coupled (DC) vacuum tube amplifiers.

Your avatar's picture is a 2465B Tektronix, with a bandwidth of 400MHz, sensitivity of 2 mV at 400MHz, and risetime on all channels of 0.875 ns.

Since we're in the mood for correctness that's a 2465, not a 2465B. 300Mhz, sensitivity of 5 mv at 300Mhz. Risetime 1.17ns.

And you are saying that a beginner can use a FAULTY Heathkit IO-10 of 200Khz bandwith....
You are kidding ?

If they have an interest in audio 200Khz bandwidth is more than enough. And as I mentioned before since it's a DC coupled scope there's very few leaky coupling capacitors to replace. And again, if there's an interest in vacuum tube circuits it's a perfect project. If I had that scope I'd fix it up.

Or you are hating beginners? 

No hate at all. Always willing to help beginners. Obviously you feel very strongly that this is a lousy project to take on. That's OK, you're entitled to that. I just think you need to tone down the rhetoric a few octaves. 

[oldway]

You give very bad advice to electronics-whiz ... Not only very bad advice but also very dangerous advice, which is much more serious.

The multimeter and the oscilloscope are two basic and essential instruments.

The first advice to give to a beginner is to never buy a faulty meter nor a faulty oscilloscope.

There you are already in error.

Then, you should not ignore that in a tube technology gear there are dangerous voltages with currents that can be greater than 30mA .... Such currents can be lethal....

This is really not what must be recommended to a beginner.

Finally, a beginner has enough things to understand in the circuits so as not to have to worry about erroneous waveforms (for example, sinusoid instead of a square wave) due to the major imperfections of the oscilloscope he use.

So, there is only one advice to give to electronics-whiz: sell or put in the cellar this faulty antiquity IO-10 and buy a modern oscilloscope that works.

[med6753]

Holy crap! How did I ever survive the 1960's when I was a beginner! 

I got my father's FAULTY O-10 scope out of storage and learned to fix it. I'm still here.

Same with FAULTY VTVM and fixed that too. I'm still here.

Back then all we had were vacuum tube circuits. Lethal voltages and all. Of course if you are going to work on these circuits you needed to understand the high voltages involved. If the Op is really interested in fixing up what you describe as a pile of junk then wouldn't it be better to help rather than shitting on his parade? THAT'S what this forum is all about.

[bd139]

When you have no money you use what you can find. Sometimes when we find something we like it even if it’s shit by modern standards. So what?

Back in the 1920-1970 period you were faced with tubes. I was on the tail end of that when my measly allowance at the age of 8 allowed me to purchase discarded tube radios and repurpose them. I was 8 and working with HT with a shitty micronta meter. Thanks to the education I got, from my father, I knew what the hell I was doing and worked safely.

Really, education is #1 way before tools. Agree with med6753 here. We can be elitist or we can help. Let’s help. I think we need to help people solve the problem they have, not tell them they have another problem.

Oldway I’m not disagreeing with you entirely for reference just the approach. Perhaps OP likes that scope. So what!?

[oldway]

Holy crap! How did I ever survive the 1960's when I was a beginner! 

I got my father's FAULTY O-10 scope out of storage and learned to fix it. I'm still here.

Same with FAULTY VTVM and fixed that too. I'm still here.

Back then all we had were vacuum tube circuits. Lethal voltages and all. Of course if you are going to work on these circuits you needed to understand the high voltages involved. If the Op is really interested in fixing up what you describe as a pile of junk then wouldn't it be better to help rather than shitting on his parade? THAT'S what this forum is all about.

Yes and - in 1960, we did not use a seat belt in the cars, we did not have a differential circuit breaker in the electrical installations, the cars did not have to go through the crash test, etc ...
You have to be stupid to want to use security rules of 1960 !!!

If you have repaired tube gears in 1960 and nothing happened to you, so much the better for you ....

But the times have changed and the security rules too.
To advise a beginner to start with repairs on circuits at 250 or 300V dc, today, it is not only irresponsible, but also criminal ...

There are enough interesting circuits to experiment in low voltage so as not to take unnecessary risks.

Moreover, in the age of computers, tubes technology, this is no longer of interest to a beginner.

[oldway]

When you have no money you use what you can find. Sometimes when we find something we like it even if it’s shit by modern standards. So what?

Back in the 1920-1970 period you were faced with tubes. I was on the tail end of that when my measly allowance at the age of 8 allowed me to purchase discarded tube radios and repurpose them. I was 8 and working with HT with a shitty micronta meter. Thanks to the education I got, from my father, I knew what the hell I was doing and worked safely.

Really, education is #1 way before tools. Agree with med6753 here. We can be elitist or we can help. Let’s help. I think we need to help people solve the problem they have, not tell them they have another problem.

Oldway I’m not disagreeing with you entirely for reference just the approach. Perhaps OP likes that scope. So what!?

If you don't have 50 bucks, better not to begin with electronics !!! Money to buy the last Smartphone, yes, people find it....If he likes electronics, OP will find 50 bucks to buy a modern decent oscilloscope, that's basic, as well as a multimeter. What you have done when you was 8 years old does not matter....times have changed a lot, nobody came back to the past....

[oldway]

From tggzzz in another topic:

For a beginner, a working scope is the priority - analogue or digitising is a second-order consideration, since both are useful.

If someone can get the educational discount, the Digilent Analog discovery should be considered very seriously.

 

[IanMacdonald]

One of the main issues with faultfinding on valve gear is the temptation to 'jockey' them.

It is normally quite OK to take a valve out and see if that clears a fault (except for a voltage regulator of course) but swapping them around is a bad idea. Valves do sometimes develop shorts, and if you swap a shorted one you will then have two stages with burned-up feed resistors instead of one.  The majority of faults are passive components, anyway. I know it's hard to convince people of that, but it's true!

All CRT oscilloscopes have some quite dangerous voltages on the CRT,  so you still need to take care when working on a newer unit with solid state amplifying stages.  One gotcha is that the cathode and grid are at a high negative potential, sometimes a couple of kV which might be enough to fry a cheap meter. This is so the deflection plates can be at a relatively low positive voltage.

When all is said and done though this is a very, very old unit, and it might take a fair bit of work to get it going well. Plus, it will probably have rather limited perfomance compared to a later model. It could be a project for later to refurb it, but for now if you want to learn scopes I'd look for something a little less ancient.

[mcinsand]

>> It was all frequency domain and you can get your SA output on 1 MHz DuMont fine and he knew it

That's why I have my IO-10.  The horizontal amplifier DC input goes very well with the voltage input to a VCO, with the vertical taking in the response signal. 

My first scope happened to be my second electronics project, and it is still a great scope: a Lavoie LA-239C with the Federal Property tag still fixed to the front.  Another former Navy radar alumnus gave me two carcasses with a challenge to use the parts to make one working scope.  That was fun, and I don't think that I could have taken a course that taught me so much so quickly.  As I remember it, horizontal sweep and Z-axis modulation took the most time, but was still just a matter of tracing back through the schematic. 

[TTWhy]

It was one of these I experienced a nasty shock. The "home kit" design and some stupid probing ended with me brushing against the 400V line and making a very memorable involuntary yelp. The thing about these HeathKit products: the fault is with the builder not the company and they flicker with just enough life so you keep going.

[vk6zgo]

It should not be exaggerated. 

We are on a forum where some people do not hesitate to say that an analog oscilloscope is totally useless.

I do not agree with that.

But come to argue that an oscilloscope whose technology dates from the WWII is usable by a beginner, there is an exaggeration.

When Dave is looking for an analog oscilloscope of less than US $ 50 on Internet, he is looking for modern decent oscilloscopes of 20 or more Mhz, not this kind of antique crap scope that no longer belongs in an electronics workshop at the moment.

Yes, it can be a museum piece and I leave it to collectors the right to waste their time and money on this kind of apparatus .... It serves, yes, to show it still works to the visitors of the museum and nothing else.

I can write about it because I had a IO-12E in the past and the first thing I have done was to buy a 7 Mhz BEM  003 MBLE when I had enough money to replace this piece of shit.

I have used similar Oscilloscopes, (AWA probably late '40s, early '50s vintage), & although they are sorely limited compared to a more sophisticated device, they will display signals, & sometimes that's all you need.
Fault finding an audio amplifier comes to mind.

Interestingly, Heathkit, & a number of others persevered with non-triggered 'scopes like this when not only were Tektronix making sophisticated Oscilloscopes in the upper price bracket, but even among cheaper stuff, Telequipment produced the early " Serviscopes", with triggering, calibrated time/div & volts/div, etc.

Probably the old style ones were quite a bit cheaper, but the little Telequipment beasties were certainly affordable for small businesses.
Not so much for individuals though, as at £200 or so, it was the best part of a year's wage in Oz in the 1950s.

[mcinsand]

>> The thing about these HeathKit products: the fault is with the builder not the company and they flicker with just enough life so you keep going.

Yes and no, with respect to faults.  A fault I have with a lot of the designers from decades ago is that they saved maybe a nickle, but no more, by not adding bleeder resistors.  Really, how much would a 4-5 resistors resistor cost in a bulk purchase, back then?  Many of the power supplies do not have a purely-resistive path to ground, and just putting a couple of 220 k? resistors in a couple of the B+ connections lets the capacitors discharge prior to work.  Always check and double-check, though.

If not for the safety concerns, an old analog scope would be the perfect project for a beginner.  I've been careful enough (paranoid?) to not have been shocked (yet) after decades of playing with tube gear.  However, the 239C scope that was my second project really got me going with reading schematics and tracing through the circuitry.  And, at the end of it, I had a useful piece of bench equipment.  Actually, that scope is big enough to be a small bench on its own   Old gear is from an age of repair, and, as long as a scope's CRT and power transformer are fine, basic electronics skills and generic parts from Mouser will get you through getting it going again.

[vk6zgo]

>> The thing about these HeathKit products: the fault is with the builder not the company and they flicker with just enough life so you keep going.

Yes and no, with respect to faults.  A fault I have with a lot of the designers from decades ago is that they saved maybe a nickle, but no more, by not adding bleeder resistors.  Really, how much would a 4-5 resistors resistor cost in a bulk purchase, back then?  Many of the power supplies do not have a purely-resistive path to ground, and just putting a couple of 220 k? resistors in a couple of the B+ connections lets the capacitors discharge prior to work.  Always check and double-check, though.

If not for the safety concerns, an old analog scope would be the perfect project for a beginner.  I've been careful enough (paranoid?) to not have been shocked (yet) after decades of playing with tube gearshift.  However, the 239C scope that was my second project really got me going with reading schematics and tracing through the circuitry.  And, at the end of it, I had a useful piece of bench equipment.  Actually, that scope is big enough to be a small bench on its own   Old gear is from an age of repair, and, as long as a scope's CRT and power transformer are fine, basic electronics skills and generic parts from Mouser will get you through getting it going again.

The omission of bleeder resistors was not primarily motivated by cost.
Many designers regarded them as unnecessary "power wasters".
This was very much in line with the parsimonious attitude towards power consumption common among Engineers at that time (maybe because the older ones "cut their teeth" on battery operated tube designs back in the 1920s.)

Serendipitously, with tube equipment, turning it off does not immediately stop the tubes from drawing anode current.
The cathode continues emission until it is no longer hot enough to do so

During this time, the capacitors discharge via the tubes.
In normal operation, this is effective, but if you turn the thing off & immediately delve into the "guts", you may be unlucky enough to get a "bite" from the HT.

Large devices with a separate "HT off" switch almost always do have bleeder resistors.

[rhb]

Much of my electronics experience was with a Heathkit 5 MHz, recurrent sweep (IO-18 IIRC).  I learned a lot with that scope despite the limitations. I have better gear now and about to do a major upgrade.

The IO-10 is only satisfactory for audio repair work.  But you can learn a lot just building AF amps and oscillators using the scope even if you can't do RF work.

Yes, tubes and especially CRTs require caution.  But I've never been bitten.  And I'm pretty sure that's true for a lot of people.

Checking the capacitors is important.  I lost a rectifier tube when a HV capacitor went out by going short.

As for whether it's worth your time, only you can decide.  In the end it's a bet on the value of what you learn at some time in the future.  The scope in itself is not worth much, but the ability to fix it is.

If the scope is in good original cosmetic condition, be very careful about what you do.

[mcinsand]

The battery design perspective would explain a lot, though the guys that trained me stressed bleeders, bleeders, bleeders, just in case there is an open failure to ground anywhere.  Also, there are bleeders, and then there are bleeders.  For HT, bleeders do consume significant power.  I think the bleeders in my 2.5 kV supply draw about 50 watts, but that is more to help build some flux density through the filter choke.  The 1 kV supply bleeders also dissipate more power than an IO-10 would draw.