Oscope ?

[Tom Phillips]

Would this be enough as a signal generator , or do I need something with more range ?

That would do it. Looks to be in excellent condition too. Heathkit manuals are available and they include lots of detailed information from initial build to operation and ongoing maintenance.

[gtrplayr1976]

They say it works. I also found this near my home ,so I may look into it also.
Tektronix model 502A Dual Beam Oscilloscope
Baker & Williamson Model 200 Audio Oscillator

[Leo_Gnardo]

Would this be enough as a signal generator , or do I need something with more range ?

That'll get you started, no problem. FWIW I've been using a Loft TS-1 for 30+ years now. Besides turning out an OK sine wave 15-30,000 Hz, it gives you a digital level and frequency reading, plus an input jack, and the screen will read you the level & frequency of whatever you've plugged in. Of course, there are limits and cautions to this - plug in too big a signal and you can wreck the meter but in 30 years of use I've never managed to do this. Also, if you're using it to suss out gain, it's a good idea to attenuate the input by a known amount, otherwise you can set up a feedback loop that will pop the op amp that drives the output. But again in 30 years I've only done that 2 or 3 times. If you can find one, it's an excellent asset.

[JoeM]

They say it works. I also found this near my home ,so I may look into it also.
Tektronix model 502A Dual Beam Oscilloscope
Baker & Williamson Model 200 Audio Oscillator

Many years ago, one of the amp repair techs the music store I worked at used a Tek 502A. I wouldn't be at all surprised if he's still using it.

[Tom Phillips]

I also found this near my home ,so I may look into it also.
Tektronix model 502A Dual Beam Oscilloscope...

That is a nice piece of vintage technology but I would not recommend that you take on such a scope unless it is definitely working. Also be advised that many people give these away for free as long as they are going to a good home. When you check out sales offers for the old tube type Tek scopes there are generally high asking prices and few real sales. The Tek discussion groups often have people pointing out Craigs list offers that say "Free if you will pick it up." Just sayin...and I have three of them sitting in my shop at this time.
Cheers,
Tom

[gtrplayr1976]

That is a nice piece of vintage technology but I would not recommend that you take on such a scope unless it is definitely working. Also be advised that many people give these away for free as long as they are going to a good home. When you check out sales offers for the old tube type Tek scopes there are generally high asking prices and few real sales. The Tek discussion groups often have people pointing out Craigs list offers that say "Free if you will pick it up." Just sayin...and I have three of them sitting in my shop at this time.
Cheers,
Tom

I found these on Craigslist . , but haven't seen any for free yet.

[Tom Phillips]

I found these on Craigslist . , but haven't seen any for free yet.

Just to be clear. Old Tek scopes don't sometimes go for free because they are worthless. It's just that people have moved on to smaller equipment or succumbed to a wife 's repeated requests to "get ride of all that junk." Since a Craig's List ad is free you could advertize for what you want too. I'll bet there are old timers that would be thrilled to find someone interested in their old scope. You might even scare up a buddy / mentor.

[gtrplayr1976]

Just to be clear. Old Tek scopes don't sometimes go for free because they are worthless. It's just that people have moved on to smaller equipment or succumbed to a wife 's repeated requests to "get ride of all that junk." Since a Craig's List ad is free you could advertize for what you want too. I'll bet there are old timers that would be thrilled to find someone interested in their old scope. You might even scare up a buddy / mentor.

I'd be more than happy to find someone like that.

[soundmasterg]

I have a good, working solid state HP dual trace 100 MHz o-scope that my grandpa used to use. I don't need it and plan to sell it eventually as I have two good Tek 2235's, but shipping from Oregon to Virginia would be a fair bit. I don't remember the model number off hand but I could look if you were interested. It would not come with probes. If you want to know more info send me a PM....but I would think you should be able to find something similar locally....

Greg

[km6xz]

That is a classic model from HeathKit, all tube and will do better for this work than 90% of the generators out there, even some costing thousands of dollars. Why? Because it has everything in one unit that is really needed, accurate frequency setting, 5%, accurate large continuous output metering in RMS volts and dbm and db, is pretty low distortion, has an accurate output attenuator, has a wide range of level from the lowest mic level input to enough to force a signal through some circuits that you are testing that appear to be dead or being able to test speakers at low level and is easily repaired since it was a kit that used standard parts. The manual for assembly also included the circuit description and theory, and troubleshooting help. It is the tube version of the signal generator I suggested. Good find.

[km6xz]

The Tek 502 and later update 502 is a typically well built lab scope from the '50s would be OK, but its vertical amplifier is limited to 50khz. It has high sensitivity, good for tracking down low level noise in preamps, and has two entirely separate beams, not chopped or alternating like most scopes so that is good. But it was very early scope technology. Take if free or close to free but the down side is that is it big, heavy and does not have as wide a bandwidth as later models of the same all tube era.
One thing about it, even if you retired it after a while, is that it can serve as a text book on how to wire a a circuit. If you study its underside, and adopt some of its assembly practices, you will have easy to repair, reliable and beautiful amp builds.
If you wanted a old tube scope, a newer version with wider bandwidth would be the more common Tektronix 545 which is a dual trace scope, not dual beam, and has a bandwidth of 30Mhz. It is just as well built as the 502 and can be found for cheap since it is heavy and consumes a lot of power. I used several for years. They are tolerant of extreme overload and are impervious to high static discharges.
Here is a bottom side image of hand wiring in the 502. The 545 is the same but a lot more density.

[Mick Bailey]

Regarding an old 465. I would wager one kept in decent condition will still be serviceable far longer than any Chinese digital scope one has today.

The build quality of these has to be just about the pinnacle of engineering excellence. Mine even has a roll of silver-loaded solder inside provided by the factory in case the DC restorer caps ever needed replacing on their ceramic cradles. All the transistors and tunnel diodes are socketed. Modern scopes don't come anywhere near. Take a look at the Tektronix forum - you'll see common failures now occurring with the 465 series, but most are well documented and easy to fix.

The cheap digital scopes need to be considered like cheap digital FX units - when they break they're pretty much junk.

[Mick Bailey]

I built a dummy load from some scrap aluminium sheet and a couple of 'pulled' fans for prolonged use. There are 4 x 4 Ohm sections each rated at 400w continuous with the fans on. The only expense (apart form my time) was the Arcol alloy-clad resistors - about £20 in total. Took a day to build.

It's handy because it can be strapped in stereo.

My main signal generator for guitar tube amps is a simple DIY 1Khz 0.707v sine source with a level control. Quick, simple and no messing around.

Test gear needs to be straightforward and reliable - when you're repairing an amp you don't want to be led astray by complex equipment. I regularly visit a guy from the 'golden age' who I hold in extremely high regard who has loads of test equipment - punched card Mullard valve tester, Sprague capacitor analyser, scopes, signal generators and all kinds of stuff. He doesn't use any of it on audio - just an AVO model 8, his brain, eyes and his hands. He repairs tube gear all day long and maintains he can find a tube fault quicker than finding the correct card for the Mullard tester. His only other must-have is a signal gen for aligning IF stages on radios after component replacement. He's got a feed off an old radio set he uses for a test input signal for audio, despite being surrounded by 'proper' generators.

[Enzo]

I think it is worthwhile to keep in mind the goals. If you are setting up a pro bench, you want tools that have the precision and breadth of performance to handle many tasks. Here I work on amplifiers, and digital systems and switching power supplies. I have precision audio generators and distortion analyzers, etc. On the other hand, the vast majority of my work is done with a voltmeter, my trusty old Fluke mainly. If you have never used a scope and are a novice, you won't be looking for contention on an address bus in a synth, and the most basic tools will do most things you want.

I don't want to sound like I recommend low performance gear, but just as a novice guitarist need not buy a new Mesa $1500 head and a $4000 Les Paul, when he can learn about fingering and playing with a used Squire strat and a $100 amp, buying a $3000 scope doesn't include the experience to operate it. For the average novice, any scope that makes a picture is enough to solve most issues that would be within the understanding of the hobbyist. Scopes are like cars, they all operate the same way. Once you learn to drive a basic car, I think you could then step into a fancier car and still motor down the road. Now if you want to drive in a road rally or on the Nascar circuit, then you need more than just the car, you need to learn all the ins and outs. But those NAscar boys started out in cheap cars on dirt tracks, their equivalent of a $50 scope. If you never picked up a guitar, a reasonable well set up Squire plays OK. And when it comes time to get a really good guitar, you will have learned what to look for from your experience. Buy an old low performance scope for next to nothing, and learn how to apply it, as your skills progress you become aware of the limitations and are better equipped to make informed purchases of gear than by trying to create a lab right out of the starting gate.

SO while a Tek 465 is a great old classic scope, don't go without one because you can't find a 465.

When you learn guitar, you learn to make an E and an A and a D, and oh that pesky G, and, what? Minor? What's a minor? You develop the ability to make a cord without positioning each finger one at a time. Then you learn to change whole chords from one to another. Then the magic of barre chords is revealed. (....and then....) you're Jeff Beck. (I left a couple steps out) Your scope is a sort of visual volt meter. At first you get a picture on the screen, some sort of dot, and a little fiddling and you can get the spot to move around. You touch the tip of your probe and see the line on the screen turn into a distorted shape. It starts to sink in that positive voltages move the line up and negative ones down. (...and then...) you are explaining to customers that there were these parasitic oscillations on the peaks, not a blown speaker. (I left a couple steps out)

Just as after a while you notice the frets on the Squire slicing your fingers, and maybe they stick up too far, and doesn't that Gibson neck just feel a little more like home? You became aware of the guitar and its shortcomings, and it puts that upgrade into perspective. YOur starter scope gets you used to seeing a trace and relating to what it represents. Later you realize that when you try to look at those DSP circuits, everything is a blur, or you note that it is hard to get a really stable image on some thing - things don't trigger as smoothly as they might. Then you can reasonable shop for more performance in a scope.


MY old beater 35MHz B&K served me well for decades. I had a wireless mic or belt pack in for service, and I needed to know if it was really transmitting. 179MHz if I recall. way over my scope's 35MHz. SO I got out a long piece of wire, made a few loops of it and set the transmitter in the middle. I flipped it on with the scope at its most sensitive setting. I couldn't resolve a waveform, but I could just see about a third of a screen division deflection whenever it was on. That was enough to tell me it was transmitting. I couldn't tell what it was sending or even if the freq was wrong, but even that far outside the ability of the scope, I could see the circuit functioned. A lot of the functioning of your test gear is between your ears.

[gtrplayr1976]

Ok...I may have jumped the gun ,but I made an offer on a scope ,and it was accepted. (really didn't expect it) It is a Tektronix 2213. Says it works ,but may need calibration. Comes with one probe ,and power cord.
Oh ,and thanks Enzo. Now I want a new Les Paul