Tektronix TDS1002b thoughts?

PinFixin

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I won't tell you how much I paid for it, but got this oscope quite a while back from a friend. I want to use it for arcade PCB repair, as well as pinball PCB repair. I've barely used an oscope to just put an asteroids picture on the screen to test a board. I don't know much about them. Is this a decent one to use, or should I sell it and get an older analog?

-Pat
 
Okay, so this brings up a question. For say, repairing a millipede board. Can I not use the digital scope at all? Or is it just tougher to use, see measurements on?

-Pat

Also, I see a lot of the Tek 22xx series for cheap. Is there that much of a difference between the two?
 
For Millipede I would only use the digital scope. I like my Rigol DS1054Z.
For any vector boards I would use BOTH the digital scope and the analog scope. The digital for logic and the analog for ... analog / vector output etc.

TEK 24xx > 22xx. :)
But ... the 22 series is nice too and more than you need for arcade repair (vectors). I have a 2247A and luv it.
If you can get a nice 22 series, you'll be happy with it.

need-help-translating-tektronix-2465a-controls-to-2247a-controls


I purchased one of these after I saw douglasgb was using one. LOL Even though I have some 2465(_, a and b) scopes.
Overall, scopes have been discussed in many KLOV threads. Read those before making a decision.
 
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Yeah, I've read most of the threads. I'll update my ebay search to the 2200 series, and just get a cheapie and keep the newer one.

My friend was a real estate agent, and in a house he sold, it was owned by the bank. Well, some things were left in it, and one of them was the college electronics engineer setup kit. A fluke 77-IV, a weird briefcase thing with some electronics testing items in it, and that oscilloscope. He gave it to me for free, but I've only used it to display a pic on an asteroids that was playing blind.

Thanks!

-Pat
 
Okay a question. Why the 50mhz or 100mhz recommendation. Is that just to measure certain frequencies on the boards. For instance if a board has a crystal that runs at 10mhz, a 10mhz oscilloscope (or maybe 20-25) would be ok for it?

If so, what is the maximum frequency for games through, oh late 80s early 90s?

-Pat

(Trying to figure out what I need. I work on Pinballs up to system 11, and arcade boards up to SF2 series).
 
Okay, perfect ty!

So, Major Havoc is the latest vector game, so most likely has the highest frequency crystal (9.16mhz).

So Channelmanic's recommendation would be a 20mhz scope, and Hudson Arcades recommendation would be a 50. So, just for vector work, looks like the 50 would get me by. Thank you again!
 
Many arcade boards use 12.096MHz XTALs. (Including vectors like Asteroids etc).
Five times that is 60MHz.
So, I personally would not use a scope under 100MHz.
My RIGOL DS1054z is "50MHz" but I hacked it to 100MHz.
My TEK 24XX are all 100MHz or better.

RULE OF THUMB: Don't cheap out on test equipment. (YMMV)
 
Huh interesting. 100 it is, and dual channel for X-Y.

-Pat
 
Dual channel is a minimum for any scope use. Accept nothing less. Always.

I would agree with others....at this point there is no reason not to get 100MHz scope. There are a lot of 12MHz crystals on arcade PCBs, and a few 17MHz as well. IIRC. So get the 100 MHz and be done.

For a little better idea *why* you want to have more bandwidth than the maximum clk frequency, here's a picture. It shows the simulated response to a 10MHz signal produced by scopes with badwidths of 10 MHz, 20 MHz, 50 MHz, and 100 MHz.

1644209569190.png


You can see that the 100MHz is quite good, with a very small fixed delay. But as you go down in bandwidth, not only is the delay worse, but the actual wave shape is much altered because the high frequency components of the CLK signal (those sharp edges) can't be reproduced by the slower scopes.

The rule of 5x is chosen because it's "good enough". I won't bore you with the math or deep theory. But you can see above that the 50 MHz (5x) scope does a pretty good job vs. the 100 MHz (10x) scope. The 20 MHz scope is bad. The 10 Mhz scope is just awful. It's not even close to a true representation of the CLK signal.
 
RULE OF THUMB: Don't cheap out on test equipment. (YMMV)

Dual channel is a minimum for any scope use. Accept nothing less. Always.

I would agree with others....at this point there is no reason not to get 100MHz scope. There are a lot of 12MHz crystals on arcade PCBs, and a few 17MHz as well. IIRC. So get the 100 MHz and be done.

For a little better idea *why* you want to have more bandwidth than the maximum clk frequency, here's a picture. It shows the simulated response to a 10MHz signal produced by scopes with badwidths of 10 MHz, 20 MHz, 50 MHz, and 100 MHz.


[snip the image]

You can see that the 100MHz is quite good, with a very small fixed delay. But as you go down in bandwidth, not only is the delay worse, but the actual wave shape is much altered because the high frequency components of the CLK signal (those sharp edges) can't be reproduced by the slower scopes.

The rule of 5x is chosen because it's "good enough". I won't bore you with the math or deep theory. But you can see above that the 50 MHz (5x) scope does a pretty good job vs. the 100 MHz (10x) scope. The 20 MHz scope is bad. The 10 Mhz scope is just awful. It's not even close to a true representation of the CLK signal.

This is all totally appropriate and very good advice (and the image supplied by @cwilkson is a brilliant and clear illustration of WHY!)

BUT I managed for close to 20 years with a cheap-ass second hand 20MHz analogue scope - but was AWARE of the limitations at higher frequencies. I did that because I never had the spare cash to spend on test gear.
So I'd say.... get the best that you can afford/justify.

(Now I have a Rigol)
 
Honestly I only want one on my desk. However, I'll go for 2 but not sure how many vector games I'll be working on in the future. So, I'm still kind of all over the place with this. Maybe it is better to get an older tektronix dual channel 100mhz, and just sell the other one I have.
 
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