Hi all

I am picked up a Kenwood KR-7400 integrated amp and am excited to get it recapped and tuned.

I've watched a couple youtube videos showing aligning channels, etc with an oscilloscope.

My question is will most any scope do what I need? I assume I need probe(s) too?
Will this $50 unit I'm trying to grab do the job well?:

https://denver.craigslist.org/ele/d/denver-oscilloscope-tektronix-453a-with/7438880163.html

 

That scope will work, but...

As a neophyte you are going to have to tolerate a steep learning curve to use an older Cathode Ray Oscilloscope (CRO). Unlike a modern Digital Storage Oscilloscope (DSO) a CRO has nothing automatic, it can't capture waveforms, and it requires you to learn, basically, what the controls are actually doing to the circuits inside.

This isn't necessarily a bad thing, but it is a thing. You will need some time to learn enough to make it useful. WIth a DSO you can learn a bit, use it for productive testing, then learn more. WIth a CRO you pretty much have to learn how and why the oscilloscope does its job, and what all the fiddly little knobs and switches do.

Not that you will use all the functionality of the scope at first. But with a DSO there is kind of a panic button. If you manage to set the scope into some kind of confusing state, you just hit "default" and it's back to a known one. WIth the CRO if you don't have a good idea of what "normal" is, you can spend a great deal of time trying to find the switch or knob that you need to make it just work at all for what you are doing.

So, not to discourage you, rather to say it is very likely worth the investment to buy a basic, modern DSO to start. But if you choose to go the CRO route, take the time to learn it or you will become very frustrated.

By the way, it appears the scope in that ad has probes included.

 

If I didn't already have an oscilloscope and I needed one, a Tektronix 453A for $50 is a steal.
If it comes with probes that's a bonus.

 

If I didn't already have an oscilloscope and I needed one, a Tektronix 453A for $50 is a steal.
If it comes with probes that's a bonus.

It ia an excellent scope. From the photos it looks operational. 50 bucks is a good deal.

 

Not only that, but a tube-type scope will have voltages inside that will literally kick your butt should you decide to play "shade tree mechanic" on it.

 

In our research lab we did not have too many scopes and we often had to share. One of the two scopes was a Tektronix 453. The other was an HP 1703A variable persistence oscilloscope. Having both on scope dollies was an absolute necessity.

I should add, the number of occasions having "storage" capabilities saved my butt is absolutely countless. Today we take storage for granted on a DSO.

 

I had a flaky, massive Tek storage tube CRO that I rescued from being tossed. I held on to it for quite a while because I remembered when it was an amazing thing. The face was huge and the screen was pretty small, but storage tube.

Eventually, I had to get rid of it. I regret it, to some extent, but it was a real boat anchor.

 

Thank you all for your insights; double thanks to Yaakov!

That sound advice will keep me looking but now for DSO.

I didn't know or consider the CRO difference but if I get it for $50, it will be there in the unlikely event I decide a steep learning curve sounds like fun. (I used to not mind that but age makes it less fun.)

Again, thanks [I'll Be Back!]

 

I'm back already. What are some scopes that are good candidates but budget priced?

Vintage microscopes are always considered money well spent compared to buying a new Amscope;
there are classics that one looks for in integrated amps; what about in oscilloscopes?

 

$50 for a working Tektronix 453A with probes, I would certainly get it. Note, it is very heavy.
If you can drive over to pick it up, so much the better.

 

Prices seem to start at $200 for used digital scopes, many without probes. Are these probes a decent substitute?
(where do all the probes go?)
https://ast-labs.com/shop/test-prob...imaDKxY9UkFFqyoVRmJsnm6gaAlD8mZEaApc3EALw_wcB

 

Prices seem to start at $200 for used digital scopes, many without probes. Are these probes a decent substitute?
(where do all the probes go?)
https://ast-labs.com/shop/test-prob...imaDKxY9UkFFqyoVRmJsnm6gaAlD8mZEaApc3EALw_wcB

Those probes look fine. If you have any candidate scopes, please don't hesitate to ask here about them. There is a lot of collective wisdom on scopes here, and a lot of practical experience with particular models.

As @MrChips says, the Tek is a great deal If you have room for it, and think you might want to learn it, it's a bargain. (Though in my opinion, for you, no substitute for a DSO.)

 

Thanks Yaakov No response from the Tek seller and probably just as well in my case.
I attempted to contact these two: (There has to be an issue with the second one.)

https://boulder.craigslist.org/ele/d/niwot-tektronix-mhz-oscilloscope/7425625277.html

https://cosprings.craigslist.org/ele/d/monument-lecroy-1ghz-oscilloscope/7433616281.html

 

Thanks Yaakov No response from the Tek seller and probably just as well in my case.
I attempted to contact these two: (There has to be an issue with the second one.)

https://boulder.craigslist.org/ele/d/niwot-tektronix-mhz-oscilloscope/7425625277.html

https://cosprings.craigslist.org/ele/d/monument-lecroy-1ghz-oscilloscope/7433616281.html

That LeCroy is quite a scope. It might not be operational. I want to suggest, if you can swing the budget, a scope like one of these two. The Siglent would be my choice, I own a similar model but four channels. The Rigol is well liked, though. One advantage of the SIglent is several active members here have them, and there is an active member who is a tech at a Siglent dealer and he is a fantastic resource.

Of course, they come with probes, so that's figured into the price. They are compact, reliable, and very capable. You can see how much simpler the controls are, which is mostly accounted for by the fact the interface includes the soft buttons, they can actually do a lot moire than the older scopes. They are both 2-channel, 100MHz models.

​

https://www.amazon.com/Siglent-Technologies-SDS1102CML-Digital-Oscilloscope/dp/B01J1MQC3G/

​

https://www.amazon.com/dp/B08J3SDBDT/

 

If you are going to make me spend that much, is the 200Mhz worth $10 more?

https://www.amazon.com/dp/B08HQL386...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

If you are going to make me spend that much, is the 200Mhz worth $10 more?

https://www.amazon.com/dp/B08HQL386...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

I believe that you would get more from the Siglent than the additional bandwidth of the 200MHz Rigol. If you want to ”future proof” the scope for the incremental cost, I would suggest buying the 200MHz Siglent for the smallish difference (which is quite small when amortized over the life of the scope).

But for audio applications, and most other things you are likely to use it for, I think 100MHz will not be a practical limitation.

 

Let me just add, I think you will be far, far happier with one of these scopes than a second hand vintage scope. And, if you find you are not using it, the resale value should be pretty high, so the “rent” you will have paid will be small.

 

Thank you again for your guidance Yaakov. Please tell me what advantages that the Siglent has over the Rigol.
(I am not questioning you advice; just hoping to learn.)

I now take it as gospel that a newer scope is the better choice. (Even though microscopes, etc are the opposite.)

 

Let me just add, I think you will be far, far happier with one of these scopes than a second hand vintage scope. And, if you find you are not using it, the resale value should be pretty high, so the “rent” you will have paid will be small.

At my age, anything I buy is going to be there with me at the end.
ebay - $335 delivered

https://www.ebay.com/itm/1547856166...1iEg5f3Xsj7uu4dK5fD6zCFkW1jUXq44aAsdMEALw_wcB

 

At my age, anything I buy is going to be there with me at the end.
ebay - $335 delivered

https://www.ebay.com/itm/1547856166...1iEg5f3Xsj7uu4dK5fD6zCFkW1jUXq44aAsdMEALw_wcB

Looks good. I am sure you will have a lot of fun with it. It will also have a learning curve but you will be able to start using the basic functions a lot faster. I am sure you will find tutorials, and you can always ask here.

As you find the need for more sophisticated functions, many of them will be there waiting behind the menus.