Date   

Re: Tek 222/224 Battery Replacement

Dave Voorhis
 

On 26 Mar 2020, at 17:02, Jeff Davis <n0dyjeff@hotmail.com> wrote:


Hi all,

One of my customers approached me a few weeks ago about a project to replace the sealed lead acid battery (now unobtainium) in Tek 222/224 scopes with lithium ion cells that presumably will continue to be available for the foreseeable future. He pointed me to a really well done project with a public domain license. There's a YouTube video on it - https://youtu.be/LJ2VS3aohV0.

After a couple of weeks of capturing schematics, sourcing parts, etc. I'm about ready to hit Send on an order for the PCBs. Before I do that, however, I wanted to check with the community to see if there's sufficient interest to order more than the minimum quantity of boards.

How about it, Tek 222/224 collectors? Any interest in a battery pack replacement based on the design in the YouTube video above?

Regards,
Jeff / N0DY
Definitely interested. I bought a 222 to add to my collection, but it’s turned out to be surprisingly useful. I’d like to replace the dud lead-acid battery but the usual replacements involve cutting the case, which I’m reluctant to do. I think the YouTube video approach doesn’t cut the case?

I didn’t watch the whole thing, admittedly.

Either way, I’m definitely interested in a board. I’m in the UK, so I don’t know if shipping might be an issue though I guess a board should fit in an envelope.


Re: TDS3000B calibration

 

On Thu, Mar 26, 2020 at 06:44 PM, amirb wrote:


no, no, of course not you, man!
I understood you weren't referring to me, Amirb!

I just tried to correct my earlier mistake: quoting the wrong part of a message.

Raymond


Re: TDS3000B calibration

amirb
 

On Thu, Mar 26, 2020 at 01:41 PM, Raymond Domp Frank wrote:


I made a mistake in my earlier reply re. amirb's post.

amirb wrote:

If you look down this thread, I tried to say the same thing but somebody
got
pissed for some reason!
Amirb, do you mean the part where I wrote " BTW, the repetition rate is
completely irrelevant for digital 'scopes"? I should add that it's as
irrelevant for analog 'scopes, apart from the fact that with the latter, trace
intensity suffers too much at lower repetition rates because of the lower duty
cycle.

Benj3867 seems to know that higher frequencies than specified cannot be used
because the automatic routine cannot handle them.

Raymond
no, no, of course not you, man!


Re: TDS3000B calibration

 

I made a mistake in my earlier reply re. amirb's post.

amirb wrote:

If you look down this thread, I tried to say the same thing but somebody got
pissed for some reason!
Amirb, do you mean the part where I wrote " BTW, the repetition rate is completely irrelevant for digital 'scopes"? I should add that it's as irrelevant for analog 'scopes, apart from the fact that with the latter, trace intensity suffers too much at lower repetition rates because of the lower duty cycle.

Benj3867 seems to know that higher frequencies than specified cannot be used because the automatic routine cannot handle them.

Raymond


Re: TDS3000B calibration

amirb
 

On Thu, Mar 26, 2020 at 01:21 PM, Raymond Domp Frank wrote:


On Thu, Mar 26, 2020 at 06:17 PM, amirb wrote:


If you look down this thread, I tried to say the same thing but somebody got
pissed for some reason!
Amirb, you mean that part? I haven't read all posts. I should add that it's as
irrelevant for analog 'scopes, apart from the fact that with the latter, trace
intensity suffers too much at lower repetition rates because of the lower duty
cycle.

Raymond
well, that was the tone I got from that message anyways...

I just looked up the TDS3000 manual, and it seems to me that they are using the pulser for tuning the channels' deskew
(hope i am using the term correctly) . They dont mention it in the manual but the setup shows why they needed the pulser

So the rise time is really not that critical as long as it is fast enough so the instrument can measure the delays between the channels
and adjust them. The more important and more expensive equipment in that setup in my view is having the 4 coaxial cables
with exact same electrical length and I believe they probably should be very phase stable


Re: TDS3000B calibration

 

On Wed, Mar 25, 2020 at 09:38 PM, benj3867 wrote:


Finally, @amirb, you are confusing calibration with performance verification.
The calibration process is not trying to measure rise-time or bandwidth
because these cannot be adjusted.
What makes you say that?

Raymond


Re: TDS3000B calibration

amirb
 


On Wed, Mar 25, 2020 at 09:38 PM, benj3867 wrote:


Finally, @amirb, you are confusing calibration with performance
verification.

Calibration means: first ""measuring"" a set of parameters from a standard calibration generator (rise time, DC gain, time interval, BW, etc....) and then
"adjusting" the instrument to bring those parameters within the predefined specs. Of course if the instrument
already meets the specs, you move on. So I dont think i was confusing anything with anything else...


Re: TDS3000B calibration

 

On Thu, Mar 26, 2020 at 06:17 PM, amirb wrote:


If you look down this thread, I tried to say the same thing but somebody got
pissed for some reason!
Amirb, you mean that part? I haven't read all posts. I should add that it's as irrelevant for analog 'scopes, apart from the fact that with the latter, trace intensity suffers too much at lower repetition rates because of the lower duty cycle.

Raymond


Re: TDS3000B calibration

amirb
 

On Thu, Mar 26, 2020 at 12:54 PM, Raymond Domp Frank wrote:


On Thu, Mar 26, 2020 at 03:48 AM, David C. Partridge wrote:


I've never encountered a fast edge calibrator (RT 150pS or so) that did even
1MHz.
Leo Bodnar's (no affiliation) fast pulse generators have 40ps max. rise time
and 10 MHz repetition rate. BTW, the repetition rate is completely irrelevant
for digital 'scopes.

Raymond
If you look down this thread, I tried to say the same thing but somebody got pissed for some reason!


Re: TDS3000B calibration

 

On Wed, Mar 25, 2020 at 05:35 PM, benj3867 wrote:


BTW, a suitable fast rise pulse generator can be easily built at home
following the instructions in appendix D of Linear Technology Application Note
47 by Jim Williams (easily found on the web).
It depends on what is needed. A pulse generator like John Williams' is suitable for checking or adjusting slew rate, which means maximum HF content. That is not the same as adjusting for optimum bandwidth, where a step response allows adjustment for flat frequency characteristics.
I doubt whether Jim Williams'pulser would produce satisfactory results or even work with the automatic adjustment routine for a TDS3000-series 'scope. At least, the pulse would have to be lengthened and flattened (using an airline, piece of coax or the like). For the same reasons, a PG506 works fine for adjusting the vertical amp of a 'scope (where 0.7 - 1000 ps rise time is fast enough) and the PG502, with comparable rise time isn't, because of the far less controlled waveshape of the PG502.

BTW sorry for mentioning Leo Bodnar's pulser in an earlier post. At the time, I hadn't seen that it was mentioned before.

Raymond


Tek 222/224 Battery Replacement

Jeff Davis
 

Hi all,

One of my customers approached me a few weeks ago about a project to replace the sealed lead acid battery (now unobtainium) in Tek 222/224 scopes with lithium ion cells that presumably will continue to be available for the foreseeable future. He pointed me to a really well done project with a public domain license. There's a YouTube video on it - https://youtu.be/LJ2VS3aohV0.

After a couple of weeks of capturing schematics, sourcing parts, etc. I'm about ready to hit Send on an order for the PCBs. Before I do that, however, I wanted to check with the community to see if there's sufficient interest to order more than the minimum quantity of boards.

How about it, Tek 222/224 collectors? Any interest in a battery pack replacement based on the design in the YouTube video above?

Regards,
Jeff / N0DY


Re: TDS3000B calibration

 

On Thu, Mar 26, 2020 at 03:48 AM, David C. Partridge wrote:


I've never encountered a fast edge calibrator (RT 150pS or so) that did even
1MHz.
Leo Bodnar's (no affiliation) fast pulse generators have 40ps max. rise time and 10 MHz repetition rate. BTW, the repetition rate is completely irrelevant for digital 'scopes.

Raymond


Re: Tek Blue Paint

Roy Morgan
 

Bert,

There has been posted (on another list and a long time ago) a method to repair scratches and bare spots on radios with wrinkle paint.

In summary: you make an impression with rubber mold-making material of an intact section, clean the spot to be repaired, apply a layer of new paint and then gently press the mold onto the spot.

The difficulty in getting black wrinkle paint onto a stripped cabinet prompted the development of that technique.

PS: the Harley Davidson motorcycle dealers were the source of the best black wrinkle paint in spray cans.

My attempt on a whole APR-4 cabinet was a disaster.

The old General Radio panel texture and finish was the most difficult to get right but it could be done.


Roy Morgan
K1LKY Western Mass

The main thing I was trying for here was to touch up some scrapes on my Tek scopes and so far that's not working out


Re: Tek 2710 suddenly won't power up??

Doug Bercich
 

You can start by downloading an operating and service manual from here:

http://w140.com/tekwiki/wiki/2710

I think in general the first thing most people do is open it up and take a look. Next up is checking the power rails.

-d


Re: Tek Blue Paint

Bert Haskins
 

On 3/26/2020 9:17 AM, Harold Foster wrote:
Bert: I like the color of the Bahama Sea - bright.

All: Expanding the topic a bit, but: what are your thoughts on the way (method) to paint? Off the shelf spray paint is convenient but is not always consistent either in color or the consistency of the paint itself. Someone mentioned using a fine knap roller - again, for me at least, that seems tricky - especially for items with holes and/or other topographical features. I've thought about a small airless sprayer (Harbor Freight's version of these have a good reputation) or even a larger air-brush setup and these would give the benefit of custom paint being able to be mixed and used. Then there is the selection of paint type - though expensive, I would think an automotive paint would be an excellent choice providing you could have it mixed in a small enough/affordable volume. I have had a couple of items powder coated locally and I have been *very* happy with the outcome there - and very inexpensive especially if they have the color(s) already in stock. So, thoughts?

Hal
I'm very seldom happy with the results of my painting efforts.

The main thing I was trying for here was to touch up some scrapes on my Tek scopes and so far that's not working out.


Bert


Tek 2710 suddenly won't power up??

Steve Nordahl
 

I have a Tektronix 2710 Spectrum Analyzer that out of the blue suddenly will no longer power up.. Worked yesterday, but not today.. S/N is #B033914

I'm the second owner for many many years.. Never had any problems with it.. Very nice piece of equipment..

Any suggestions?? The fuse in the back of the unit is fine.. Not sure what's going on..

Steve
Nazareth, Pa.


Re: Tek Blue Paint

Paul Amaranth
 

I use one of the cheap HLVP guns from HF; it can be used for latex
or enamel, just has to be thinned properly. It works pretty well.

It's unlikely you'll find someone to mix up less than a gallon of
custom color.

Most auto paints are catalized enamels these days and need hazmat
gear to handle safely. Most of the time I stick with a Sherwin
Williams industrial enamel. One word of warning: if you spray
it outside (which is the smart thing to do if you don't have a
paint booth), it will attract skads of gnats that like to land
in the wet paint where they dissolve. Ugh.

PaulA

On Thu, Mar 26, 2020 at 06:17:36AM -0700, Harold Foster wrote:
Bert: I like the color of the Bahama Sea - bright.

All: Expanding the topic a bit, but: what are your thoughts on the way (method) to paint? Off the shelf spray paint is convenient but is not always consistent either in color or the consistency of the paint itself. Someone mentioned using a fine knap roller - again, for me at least, that seems tricky - especially for items with holes and/or other topographical features. I've thought about a small airless sprayer (Harbor Freight's version of these have a good reputation) or even a larger air-brush setup and these would give the benefit of custom paint being able to be mixed and used. Then there is the selection of paint type - though expensive, I would think an automotive paint would be an excellent choice providing you could have it mixed in a small enough/affordable volume. I have had a couple of items powder coated locally and I have been *very* happy with the outcome there - and very inexpensive especially if they have the color(s) already in stock. So, thoughts?

Hal





!DSPAM:5e7cab80188087073745389!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@AuroraGrp.Com | Unix & Windows


Re: Tek Blue Paint

Harold Foster
 

Bert: I like the color of the Bahama Sea - bright.

All: Expanding the topic a bit, but: what are your thoughts on the way (method) to paint? Off the shelf spray paint is convenient but is not always consistent either in color or the consistency of the paint itself. Someone mentioned using a fine knap roller - again, for me at least, that seems tricky - especially for items with holes and/or other topographical features. I've thought about a small airless sprayer (Harbor Freight's version of these have a good reputation) or even a larger air-brush setup and these would give the benefit of custom paint being able to be mixed and used. Then there is the selection of paint type - though expensive, I would think an automotive paint would be an excellent choice providing you could have it mixed in a small enough/affordable volume. I have had a couple of items powder coated locally and I have been *very* happy with the outcome there - and very inexpensive especially if they have the color(s) already in stock. So, thoughts?

Hal


Re: TDS3000B calibration

 

On Wed, Mar 25, 2020 at 09:38 PM, benj3867 wrote:


Finally, @amirb, you are confusing calibration with performance verification.
To use some of your words, "you are confusing calibration with adjustment".
Obviously the word Calibration mean different things to different people.
Calibration, at least how we did it at Tek in Europe, was almost always
Performance Verification. There were even two Calibration options for customers
to choose from, PV or Adj, with different prices of course.
In the contract with our major customer it said that if a test was within 70%
of spec no action should be done. If it came out between 70 and 100% of spec
adjustment should be done. If the adjustment failed to return it to less
than 70% or couldn't be done the instrument would still Pass. In either case
it should be noted on the Certificate. And of course if the instrument was
out of spec and couldn't be brought back to within it would Fail the Calibration.

/Håkan


Re: Tek Blue Paint

Harold Foster
 

Bert: I, for one, would very much like to see the photo - I have several Tek scopes that I would like to repaint and having a close, consistent color would help greatly. I'll PM you separately with my email address.

Hal

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