old 'scope for home tube amp work

[nosaj]

Go see it. Does it make a traces on the screen? Touch the end of the probe, does it make an ugly squiggle trace? Then it is working, and worth that money. I expect to pay $30 for a basic probe anyway, if yours are working that is a bonus.


The Tek 317 is nothing like the Tenma. Is he selling two scopes?

Of the 2 if it were me. I would choose the tenma provided it's working. The TEK 317 was introduced in 1959 and sold till 1972. And will likely need work.
nosaj

[Enzo]

I also would chose the Tenma, looking at photos of the Tek, it used the old thread on probe connectors, which would not be compatible with modern BNC probes.

[mikepukmel]

Go see it. Does it make a traces on the screen? Touch the end of the probe, does it make an ugly squiggle trace? Then it is working, and worth that money. I expect to pay $30 for a basic probe anyway, if yours are working that is a bonus.


The Tek 317 is nothing like the Tenma. Is he selling two scopes?

Thanks, the Tenma is not the same seller. I keep checking Craigslist. Looks like this guy has bought some old tech school stuff that wasn't used very much. The guy with the old tek 317 has lots of odd stuff. Some really ancient tube stuff. Nice museum pieces. The guy with the Tenma also has a few signal generators for cheap, so can at least do basic checks on the Tenma with that, and I need a signal generator for audio as well.

[mikepukmel]

Thanks everyone. Hope to get up to check out the Tenma today after work. By the photos, it looks very lightly used. I know the very basics of how the scope works, anything in particular I should look for, besides trying out the signal generator and checking that I get a reasonable trace on both channels?

[mikepukmel]

Looks pretty clean. Will report how it works later today, hopefully.


I tried for hours last night to get a manual online, no luck. Some really old posts that lead to dead links. Any ideas where I can hunt for a manual for this scope?
Thanks,
Mike

[glebert]

Hope this isn't a threadjack, but input voltage ranges were discussed here. I am trying to figure out how to determine the maximum voltages (AC and DC) that an old tube oscilloscope can handle. Mine is a Telequipment S51b. The manual for it is here: https://www.hobbielektronika.hu/foru....php?id=118371

I am much more used to solid-state scopes that will put their voltage range right on the input port.

Thanks,
Greg

[Tom Phillips]

Hope this isn't a threadjack, but...

Yes. It would be best that you start a new thread specific to your topic.
R/
Tom

[Tom Phillips]

...I tried for hours last night to get a manual online, no luck.

Mike,
The Tenma was actually manufactured by the Hung Chang company. The same Hung Chang product was re-branded and sold by many other companies under their own brand names and model numbers. It appears that Tenma even used different model numbers for the same, or very similar, scopes.

Attached is a manual for a Tenma Model 72-720. The product described in the manual looks identical to the Tenma Model 72-320 photo that you posted. At the very least the operating instructions will apply to the scope you are interested in. Maybe they bumped up the model number for marketing purposes in a new model year. Even if the model number was identical that is no guarantee that the schematics & service information would be spot on for every like numbered model scope. Never-the-less, the information in the attached manual will be useful to you if you get the scope. The controls are very basic for a scope so you should be able to find a YouTube tutorial about scope operation which will help you understand how to set up and use the controls.

Cheers,
Tom
Tenma 72-720 Manual.pdf

[mikepukmel]

Thanks Tom!!

[Enzo]

Scopes all work about the same, in the sense guitar amps all work the same. If you look through most any scope manual, iot will apply.

[SoulFetish]

Maybe I can help. I just went through this.
First, let me say that vintage tek scopes are worth having around if only just to look at the build quality for inspiration. I had a vintage Tektronix Dual Beam 556 I got for free from a dude who just needed his garage space full of old ham gear cleaned out so they could tear it down. I went back and forth on whether or not to put the work into to get it up and running. I believe this model was mostly solid state except for the horizontal amplifiers and sweep generators. Totally beautiful machine. I probably would have held onto as well it if it wasn't the size of a shed.


But, it came down to the fact that I needed an oscilloscope for working on projects, I didn't need one to become the project. At least not now. I found someone to give me $70 in non working condition(I think it may have needed a CRT). I put the money towards a RIGOL DS1102 which I got for $190 shipped. Whats your budget?
you may want to check this out as well:
RIGOL DS1102E Digital Oscilloscope 888884877 | eBay

[mikepukmel]

Maybe I can help. I just went through this.
First, let me say that vintage tek scopes are worth having around if only just to look at the build quality for inspiration. I had a vintage Tektronix Dual Beam 556 I got for free from a dude who just needed his garage space full of old ham gear cleaned out so they could tear it down. I went back and forth on whether or not to put the work into to get it up and running. I believe this model was mostly solid state except for the horizontal amplifiers and sweep generators. Totally beautiful machine. I probably would have held onto as well it if it wasn't the size of a shed.
[ATTACH=CONFIG]44639[/ATTACH]
[ATTACH=CONFIG]44640[/ATTACH]
But, it came down to the fact that I needed an oscilloscope for working on projects, I didn't need one to become the project. At least not now. I found someone to give me $70 in non working condition(I think it may have needed a CRT). I put the money towards a RIGOL DS1102 which I got for $190 shipped. Whats your budget?
you may want to check this out as well:
RIGOL DS1102E Digital Oscilloscope 888884877 | eBay

Thanks! yeah, that was even a bigger concern for me (getting a scope that did not become a big project) since my electronics knowledge is so weak, and I don't need much except to look at audio traces! Budget: less than $400 or $500.00. Preferably about $350 or so. The Rigol for 200 sounds very good. I will check them out. And its digital!!!

[Tom Phillips]

...And its digital!!!

Which, in my opinion, is not necessarily a good thing. Especially for inexpensive scopes.

[mozz]

4 scopes, 3 distortion analyzers and other junk today for $20, they are out there.

[bob p]

hamfest?