Time mark generator.I need opinions:

[SAUL BRITTO]

http://produto.mercadolivre.com.br/MLB-741929117-labindependente-gerador-de-marcas-001-a-500mhz-_JM

Please, opinions are welcome.
Anybody knows the model on the link?

[justinDavidow]

That appears to be a Tektronix 2901

Someone did a teardown here a few years back:
https://www.eevblog.com/forum/reviews/tektronix-2901-time-mark-generator-tear-down-inspection/

[sorenkir]

I have one, it suffered from intermittent contact due to one bad solder joint, easily fixed once identified and you manage to remove the boards...
It has some sort of "ovenized" quartz oscillator, but with mechanical thermal control!
The 20/100/200/500 MHz output amplitude is not calibrated.
Not of very much use, except if you plan to check/calibrate timebases of vintage analog scopes...
Michel.

[tautech]

I have one, it suffered from intermittent contact due to one bad solder joint, easily fixed once identified and you manage to remove the boards...
It has some sort of "ovenized" quartz oscillator, but with mechanical thermal control!
The 20/100/200/500 MHz output amplitude is not calibrated.
Not of very much use, except if you plan to check/calibrate timebases of vintage analog scopes...
Michel.

That's exactly their intended use and invaluable for such.

[SAUL BRITTO]

Thank you all for answers. This other device is capable of do the same than time marker?
http://produto.mercadolivre.com.br/MLB-745859341-gerador-de-pulso-hp8082a-arduino-agilent-_JM

Somebody  on the forum said me that a pulse generator is excelent to time base calibration too.
You agree?

[markce]

pulse generator is excelente to calibrates scopes too

Depends on its specs. You will need like 1% (or 5%) calibrated pulse repetition accuracy and stability and
(depending on the scope to calibrate) high rates. With a frequency counter, lack of accuracy in the generator can be compensated for.
A fast digital generator could do nice.

[SAUL BRITTO]

pulse generator is excelente to calibrates scopes too

Depends on its specs. You will need like 1% (or 5%) calibrated pulse repetition accuracy and stability and
(depending on the scope to calibrate) high rates. With a frequency counter, lack of accuracy in the generator can be compensated for.
A fast digital generator could do nice.

markce do you know the model of the link? It's a HP8082A.
http://www.libertytest.com/assetmanager/uploaded/pdf-20081211-164348-hp_8082a.pdf

[tggzzz]

http://produto.mercadolivre.com.br/MLB-741929117-labindependente-gerador-de-marcas-001-a-500mhz-_JM

So, you think that is your solution. It may or may not be.

If you tell people your problem, you may get better answers or better solutions.

[SAUL BRITTO]

http://produto.mercadolivre.com.br/MLB-741929117-labindependente-gerador-de-marcas-001-a-500mhz-_JM

So, you think that is your solution. It may or may not be.

If you tell people your problem, you may get better answers or better solutions.

Somebody said me that a pulse generator like this on the link is capable of the same work as a time generator.Is this I want to know.I believe the people understood my question.



Look: Thank you all for answers. This other device is capable of do the same than time marker?
http://produto.mercadolivre.com.br/MLB-745859341-gerador-de-pulso-hp8082a-arduino-agilent-_JM

Somebody  on the forum said me that a pulse generator is excelent to time base calibration too.
You agree?


Quote
pulse generator is excelente to calibrates scopes too
Depends on its specs. You will need like 1% (or 5%) calibrated pulse repetition accuracy and stability and
(depending on the scope to calibrate) high rates. With a frequency counter, lack of accuracy in the generator can be compensated for.
A fast digital generator could do nice.
« Last Edit: Today at 12:18:49 AM by markce »

[SAUL BRITTO]

TGGZZZ> I think the people understood my question...

[SAUL BRITTO]

tggz if you are not satisfied with my presence at this forum and happens to be an administrator feel free to block my profile I'm sorry but I hate persecution and stupid reproaches.

[tggzzz]

TGGZZZ> I think the people understood my question...

The trick is to learn to ask the right question. That's a good lesson to learn in life, not just on this forum. You will find that it is easy to answer questions, but much more difficult to determine which is the important questiom - i.e. the one which causes you to do A rather than B.

If you look at your first post, you gave a link and asked for opinions.

An answer that is a completely sufficient answer to that question is "It will not be a good way of checking your radio receiver's calibration".

Now, if you wanted to use it for some other purpose, it would help if you stated the purpose. It is also polite, since it avoids people wasting their time giving answers that don't help you.

Anyway, either you will learn, or you won't.

[SAUL BRITTO]

TGGZZZ> I think the people understood my question...

The trick is to learn to ask the right question. That's a good lesson to learn in life, not just on this forum. You will find that it is easy to answer questions, but much more difficult to determine which is the important questiom - i.e. the one which causes you to do A rather than B.

If you look at your first post, you gave a link and asked for opinions.

An answer that is a completely sufficient answer to that question is "It will not be a good way of checking your radio receiver's calibration".

Now, if you wanted to use it for some other purpose, it would help if you stated the purpose. It is also polite, since it avoids people wasting their time giving answers that don't help you.

Anyway, either you will learn, or you won't.

As I said: if you don't agree with my presence on the forum...

[Eheran]

What are you even talking about?
He wants to help you. But for anyone to be able to help you further... u have to give us information about what you actually do/need. No need to make tripple-posts every 8min. Futher there is "ever" any need for a quote of a whole post. Only quote if u want to respond to a specific part of a post and then only quote that part...
And since you only have one sentence and its the last post in this thread: I dont need to quote you now at all.

[tggzzz]

No need to make tripple-posts every 8min.

Well, yes.

See what lead up to my response https://www.eevblog.com/forum/repair/can-anybody-explain-me-really-how-works-that-time-base-of-hp-scopes-1740a-and/msg884541/#msg884541

[markce]

HP8082A certainly is a fast pulse gen. As far as I can see, it is not super precise, so you'll need a frequency counter as well.
The HP8082A uses special HP IC's, so be carefull not to break it.
Do you really need this fast? To check/adjust a 20MHz or 50MHz scope it's overkill.

[chris_leyson]

Hi Saul, the TEK 2901 is an old piece of equipment you would need to replace the electrolytic caps if they havn't already been replaced and check the sockets for any signs of corrosion. Check the crystal oscillator with a frequency counter if you have one.

Chris

[ebastler]

HP8082A certainly is a fast pulse gen. As far as I can see, it is not super precise, so you'll need a frequency counter as well.
The HP8082A uses special HP IC's, so be carefull not to break it.
Do you really need this fast? To check/adjust a 20MHz or 50MHz scope it's overkill.

I agree. If this purchase is triggered just by the HP scope alignment task described in the other thread which tggzzz linked to, then buying a dedicated timing or pulse generator might be overkill per se.

I understand that you already have a function generator, but do not quite trust its output frequencies? Why not buy a decent frequency counter instead? That would help you to establish a known reference signal for timing adjustments, and will be much more useful for your future electronics projects.

Saul -- giving advice along those lines would indeed be easier if you could state what problem you are trying to solve. I.e. what you want to do with the generator?  (Including e.g. some details about the type(s) of scope you want to adjust, if that is the main purpose.)

[SAUL BRITTO]

I bought this unit of tek 2901 and it's in my bench I see that orange light signal named oven,it some times goes on and of.I need to know if it just lit when is trying to do an adjustment of frequency. Is this a normal behavior?

[1xrtt]

Yes, the internal crystal is kept inside an oven, for thermal stability, so the oven turns on and off frequently.
Here is a picture:


from this thread:
https://www.eevblog.com/forum/reviews/tektronix-2901-time-mark-generator-tear-down-inspection/msg73606/#msg73606

[SAUL BRITTO]

Yes, the internal crystal is kept inside an oven, for thermal stability, so the oven turns on and off frequently.
Here is a picture:


from this thread:
https://www.eevblog.com/forum/reviews/tektronix-2901-time-mark-generator-tear-down-inspection/msg73606/#msg73606

Thank you. I bought this device recently in truth, the mail delivered me today and, I was in doubt.

[PaulAm]

Did you get the manual for that generator?

You can find the service/operating manual here:
  http://w140.com/tekwiki/wiki/2901

The sixth paragraph under operating instructions says to allow 2 hours for the oven temperature to stabilize and then 5 minutes after turning it on.  The note immediately following that explains when that light comes on.

The first thing I do when I get a piece of equipment is track down a manual and read it.  That's generally more efficient than asking random questions.

[tggzzz]

The first thing I do when I get a piece of equipment is track down a manual and read it.

Personally I look at the manual before I buy something. If I can't find a manual, I usually don't buy it.

That's generally more efficient than asking random questions.

Arguably that's not a more efficient use of his time He would probably get a useful answer faster that way, though.