Test Equipment Anonymous (TEA) group therapy thread

[xrunner]

The Boonton Model 42A button is done. I did away with the more complicated internal design of the original because, well, I didn't need to duplicate it. I simply made the opening the same size as the measured switch shaft. I wasn't sure it it would fit at all but that's where I wanted to start. Turns out it was perfect, it fit just right - not too tight and not too loose. That's all I can hope for in a first attempt. It's the last black button at the bottom.

After printing I put a dot of white model paint in the dimple, and it was done. The guy I'm giving the power meter to was thrilled that I even went to this much trouble. However, a person could make it more exacting by sanding and painting with glossy black paint. Because I had the machine set up for this, I printed two more buttons (why not?) to be included in a small plastic bag which will contain the original bulbs too.

More about the lighting in coming posts ... no gorillas will be involved in this conversion.

[Vince]

Next owner is lucky to have found you ! 

I am starting to think you purposefully seek old cheap / needy TE just so you can have an excuse to play with your 3D printer to make this or that custom part...

[xrunner]

I am starting to think you purposefully seek old cheap / needy TE just so you can have an excuse to play with your 3D printer to make this or that custom part...

You are probably right!

I think I'm going to get me a bottle of glossy black model paint. I have a whole bunch of colors for model railroad painting but that's all flat paint. I have painted PLA plastic but not with gloss paint. I am interested in just how good I can make a button look. Vince - if I can make it look like the original gloss plastic button I'll show you and see if I can get you approval. If I can then, I will have achieved what I once thought was impossible. 

[Zucca]

What do you guys think about a Picoscope USB thing? Do you have one?

[mnementh]

The boi goes back to school tomorrow, so I worked him today like a rented mule. About 1/2 done... maybe a little more. Getting to this point involved moving a dozen or so heavy-ass 1m³ cartons full of office stuffs, kitchen stuffs, tool stuff all stacked to the ceiling... as well as another dozen or so 60 gallon totes as shown yesterday. Oh, and a gas range. 

None of which are the heaviest stuff on the trailer by far. 

mnem
*toddles off to soak his aching scales*

[mansaxel]

Getting to this point involved moving a dozen or so heavy-ass 1m² cartons

The effort is splendid, except that it sounds a bit flat. Was there only area and not volume to those cartons?

 

[tonyalbus]

today i received a present to myself 🙂 on Dutch ebay 'marktplaats' i bought an Tektronix TDS1001C-EDU   40MHz /500MS/s

turnsout...its brandnew, in an original box with all cd's books 2 100MHz probes original and trim screwdriver... its all there and original.. amazing !
just checked the menu... it says 5 power cycles ))
C version has colorscreen, EDU (for schools) had all this nice software too.. cool

So if one is looking for this EDU software, i can put it online for download.

[Robert763]

What do you guys think about a Picoscope USB thing? Do you have one?

They are excellent. I currenly have 3 on regular use. A 8 bit 20MHz small as portable scope and gamma spectrometer. A 16 bit 2 channel for high resolution work both 'scope and gamma spec. Modtly bench. And then a 4 Channel 16 bit automotive kit.
I also have a few of their older parallel port 'scopes from previous use and some of there data loggers and temperature measurement interfaces.
Support is excellent as is the software. Great serial decoding at no cost too. I highly recommend them. Been using them personally and professionally for over 20 years.

[Vince]

I am starting to think you purposefully seek old cheap / needy TE just so you can have an excuse to play with your 3D printer to make this or that custom part...

I am interested in just how good I can make a button look. Vince - if I can make it look like the original gloss plastic button I'll show you and see if I can get you approval. If I can then, I will have achieved what I once thought was impossible. 

Wow I didn't think I was seen as being so anal... oh well. I just like to make things as good as possible... within reason. If you can make something noticeably better with a small to moderate investment in time (learning curve / experimentation ) and money (tooling/supplies)... then why not try it...

OK so the two main things I would try to improve on your knobs, what jumps at me, are :

- White dot is too big, larger diameter than the original. Either too much paint, or you did not measure it accurately enough, or you did but the printer did not manage to do it properly in which case you need to compensate for that by asking it to make a smaller diameter so that once printed it ends up at the appropriate diameter.

- On your first pic the narrow side of the button is clearly undulating like mad, not straight at all. I guess it's inevitable with a 3D printer that melts plastic.... maybe printing the button more slowly would improve it, but you will always get ridges anyway, even if the overall shape is straight, as can be seen on the underside of the button.
So... I guess the only way to "clean up" these ridges and undulation is to mill the part on all 4 sides.
I guess you don't have a milling machine but maybe if you have a drill press, you could buy a little milling tool that you can mount like it were a drill bit. That must exist somewhere...
Well you could do it by hand (with the part held in place in a vice at least...) with a rasp. When I did my training in aviation, making custom aluminium parts by hand, we had a special rasp we called " râpe à Dural ". The "teeth" were shaped like circles/arcs, what you would get if you had put the part in a milling machine. It was like milling.. but with a hand tool. So you could easily make an edge or surface perfectly straight and smooth, was great. I don't know how it's called in English....

Top side of the knob being concave, that won't work, so maybe remove imperfections by hand as best you can with a scalpel, or simply with wet sanding at increasingly fine grit, until smooth enough to be painted.  Actually since the button is small, you could do it all maybe with sand paper. Like you do when you sharpen wood working tools : you glue the sand paper flat onto a hard & flat surface, like say an old mirror or something. You secure that to your bench, then you work the button faces flat onto that sand paper...  You need to try everything see what works best ! 

[Specmaster]

today i received a present to myself 🙂 on Dutch ebay 'marktplaats' i bought an Tektronix TDS1001C-EDU   40MHz /500MS/s

turnsout...its brandnew, in an original box with all cd's books 2 100MHz probes original and trim screwdriver... its all there and original.. amazing !
just checked the menu... it says 5 power cycles ))
C version has colorscreen, EDU (for schools) had all this nice software too.. cool

So if one is looking for this EDU software, i can put it online for download.

Nice haul, why has it a another fascia overlay, what is that used for?

[tonyalbus]

today i received a present to myself 🙂 on Dutch ebay 'marktplaats' i bought an Tektronix TDS1001C-EDU   40MHz /500MS/s

turnsout...its brandnew, in an original box with all cd's books 2 100MHz probes original and trim screwdriver... its all there and original.. amazing !
just checked the menu... it says 5 power cycles ))
C version has colorscreen, EDU (for schools) had all this nice software too.. cool

So if one is looking for this EDU software, i can put it online for download.

Nice haul, why has it a another fascia overlay, what is that used for?

Thank you! 
yes super lucky.. it did say used and the price i paid was also for used... 
That extra overlay is German, i will keep the English

[Specmaster]

I am starting to think you purposefully seek old cheap / needy TE just so you can have an excuse to play with your 3D printer to make this or that custom part...

You are probably right!

I think I'm going to get me a bottle of glossy black model paint. I have a whole bunch of colors for model railroad painting but that's all flat paint. I have painted PLA plastic but not with gloss paint. I am interested in just how good I can make a button look. Vince - if I can make it look like the original gloss plastic button I'll show you and see if I can get you approval. If I can then, I will have achieved what I once thought was impossible. 

Personally, if you are intending to make a better match (already good IMO), I'd only bother with the top 5 to 7 mm as that is the only part of the knob visible, why wast e all that effort on parts that are not normally seem

[xrunner]

OK so the two main things I would try to improve on your knobs, what jumps at me, are :

- White dot is too big, larger diameter than the original. Either too much paint, or you did not measure it accurately enough, or you did but the printer did not manage to do it properly in which case you need to compensate for that by asking it to make a smaller diameter so that once printed it ends up at the appropriate diameter.

Thanks for your observations.

Yes, due to the nature of the 3D printed surface it can draw paint away in very tiny "channels". That's all that is. The best way (searching for perfection now) is to:

Sand the button with very fine sandpaper

Prime the button (or part)

Sand again

Prime again

Sand once more

Paint with gloss black

Use toothpick to "dot" the dimple


^^^ all this is for a perfection part that makes or breaks the restoration. Would be needed for a museum piece with a knob or button entirely exposed in all ways but the back.

- On your first pic the narrow side of the button is clearly undulating like mad, not straight at all. I guess it's inevitable with a 3D printer that melts plastic.... maybe printing the button more slowly would improve it, but you will always get ridges anyway, even if the overall shape is straight, as can be seen on the underside of the button.

Personally, if you are intending to make a better match (already good IMO), I'd only bother with the top 5 to 7 mm as that is the only part of the knob visible, why wast e all that effort on parts that are not normally seem

Yes that was caused by trimming with a knife - not the printer. As Specmaster said, almost 75% of the button's body is not visible (never seen) when the bezel is installed, so it doesn't really matter. But yes if you want to talk absolute perfection sanding would be the way to go.

I want to take this as a challenge Vince. I want to see how good I can make it look after it comes off the build plate. I need to buy some glossy paint. I already have airbrush primer which will work great for this, and very fine sandpaper.

Stay tuned ...

P.S. I just ordered Tamiya gloss black & gloss white

[TERRA Operative]

I am starting to think you purposefully seek old cheap / needy TE just so you can have an excuse to play with your 3D printer to make this or that custom part...

I am interested in just how good I can make a button look. Vince - if I can make it look like the original gloss plastic button I'll show you and see if I can get you approval. If I can then, I will have achieved what I once thought was impossible. 

Wow I didn't think I was seen as being so anal... oh well. I just like to make things as good as possible... within reason. If you can make something noticeably better with a small to moderate investment in time (learning curve / experimentation ) and money (tooling/supplies)... then why not try it...

OK so the two main things I would try to improve on your knobs, what jumps at me, are :

- White dot is too big, larger diameter than the original. Either too much paint, or you did not measure it accurately enough, or you did but the printer did not manage to do it properly in which case you need to compensate for that by asking it to make a smaller diameter so that once printed it ends up at the appropriate diameter.

- On your first pic the narrow side of the button is clearly undulating like mad, not straight at all. I guess it's inevitable with a 3D printer that melts plastic.... maybe printing the button more slowly would improve it, but you will always get ridges anyway, even if the overall shape is straight, as can be seen on the underside of the button.
So... I guess the only way to "clean up" these ridges and undulation is to mill the part on all 4 sides.
I guess you don't have a milling machine but maybe if you have a drill press, you could buy a little milling tool that you can mount like it were a drill bit. That must exist somewhere...
Well you could do it by hand (with the part held in place in a vice at least...) with a rasp. When I did my training in aviation, making custom aluminium parts by hand, with had a special rasp we called "râpe à Dural ". The "teeth" were shaped like circles/arcs, what you would get if you had put the part in a milling machine. It was like milling.. but with a hand tool. So you could easily make an edge or surface perfectly straight and smooth, was great. I don't know how it's called in English....

Top side of the knob being concave, that won't work, so maybe remove imperfections by hand as best you can with a scalpel, or simply with wet sanding at increasingly fine grit, until smooth enough to be painted.  Actually since the button is small, you could do it all maybe with sand paper. Like you do when you sharpen wood working tools : you glue the sand paper flat onto a hard & flat surface, like say an old mirror or something. You secure that to your bench, then you work the button faces flat onto that sand paper...  You need to try everything see what works best ! 

If the dot was made the same size as the original, the paint is probably sucking into the gaps between the layers by capillary action. This can be minimised by using thicker paint and/or making the dot smaller than needed to compensate accordingly for the paint spread or paint the whole part in black/desired colour to make it shiny, then put the dot on afterwards.

[EDIT] I spoke too soon, but the below is something to be aware of.
The ripple is a problem with the leadscrew/etc on the respective axis. A slightly bent leadscrew with the nut rigidly coupled to the build-plate will make this effect for example. It will be a matter of tuning the machine to minimise this effect (A common method is to slightly loosen the fixings holding the nut to the build plate, just enough to allow some X-Y movement to take into account the wobble of the leadscrew, but not loose enough to allow any slack in the Z direction).

As for the layer striations, either printing the part slightly larger then sanding back, printing in ABS and using acetone vapour, or painting and sanding will make it nice and shiny.

[TERRA Operative]

today i received a present to myself 🙂 on Dutch ebay 'marktplaats' i bought an Tektronix TDS1001C-EDU   40MHz /500MS/s

turnsout...its brandnew, in an original box with all cd's books 2 100MHz probes original and trim screwdriver... its all there and original.. amazing !
just checked the menu... it says 5 power cycles ))
C version has colorscreen, EDU (for schools) had all this nice software too.. cool

So if one is looking for this EDU software, i can put it online for download.

Oh nice!
If there's anything interesting on those CD's, you should upload to the tekwiki.

[factory]

today i received a present to myself 🙂 on Dutch ebay 'marktplaats' i bought an Tektronix TDS1001C-EDU   40MHz /500MS/s

turnsout...its brandnew, in an original box with all cd's books 2 100MHz probes original and trim screwdriver... its all there and original.. amazing !
just checked the menu... it says 5 power cycles ))
C version has colorscreen, EDU (for schools) had all this nice software too.. cool

So if one is looking for this EDU software, i can put it online for download.

Nice haul, why has it a another fascia overlay, what is that used for?

Thank you! 
yes super lucky.. it did say used and the price i paid was also for used... 
That extra overlay is German, i will keep the English

Hopefully it's better than the TBS EDU one that BD139 bought & sold. He gave up trying to hack it, there was a video in the TEA thread showing how crap it was but it's now unavailable.
https://www.eevblog.com/forum/testgear/tektronix-tbs1000-series-hacking/msg3630809/#msg3630809

David

[Zucca]

They are excellent. I currenly have 3 on regular use. A 8 bit 20MHz small as portable scope and gamma spectrometer. A 16 bit 2 channel for high resolution work both 'scope and gamma spec. Modtly bench. And then a 4 Channel 16 bit automotive kit.
I also have a few of their older parallel port 'scopes from previous use and some of there data loggers and temperature measurement interfaces.
Support is excellent as is the software. Great serial decoding at no cost too. I highly recommend them. Been using them personally and professionally for over 20 years.

Thanks Rob, so my assumptions were right.
Shit now it is confirmed: I want one before end 2022. Budget is max $1K, ideally buying for parts and fix it.

Oh well another device on my wish list...

I am still debating if 16bit or less....

[tonyalbus]

today i received a present to myself 🙂 on Dutch ebay 'marktplaats' i bought an Tektronix TDS1001C-EDU   40MHz /500MS/s

turnsout...its brandnew, in an original box with all cd's books 2 100MHz probes original and trim screwdriver... its all there and original.. amazing !
just checked the menu... it says 5 power cycles ))
C version has colorscreen, EDU (for schools) had all this nice software too.. cool

So if one is looking for this EDU software, i can put it online for download.

Oh nice!
If there's anything interesting on those CD's, you should upload to the tekwiki.

Jarid.. 'The Tekwiki' ??  for a none tekboy (for now) .. i google like 20 tekwiki's ?

[Vince]

OK so the two main things I would try to improve on your knobs, what jumps at me, are :

- White dot is too big, larger diameter than the original. Either too much paint, or you did not measure it accurately enough, or you did but the printer did not manage to do it properly in which case you need to compensate for that by asking it to make a smaller diameter so that once printed it ends up at the appropriate diameter.

Thanks for your observations.

Yes, due to the nature of the 3D printed surface it can draw paint away in very tiny "channels". That's all that is. The best way (searching for perfection now) is to:

Sand the button with very fine sandpaper

Prime the button (or part)

Sand again

Prime again

Sand once more

Paint with gloss black

Use toothpick to "dot" the dimple

OK I see... inherent to printing process, crap 

You could just put prime/paint the top of the knob to fill the "crevasses" or whatever the white paint had seeped into. Then sand that down to be smooth. Then make a clean dimple using a cutting tool. Secure the knob in a vice, bring it to the drill press. Don't use a regular drill bit as it will probably make a mess. Instead use one of those bits that have a flat end/face, rather than pointy/conical. I don't know how it's called.... we used on aircraft fitting when a fastener was too close to the radius / pocket edge and the head of the fastener would be prevented from sitting perfectly flat on the fitting surface, hence not doing its job properly. We called it "spot face "IIRC in English on the drawings. Google confirms that, here is a random YT example :

On your first pic the narrow side of the button is clearly undulating like mad, not straight at all. I guess it's inevitable with a 3D printer that melts plastic.... maybe printing the button more slowly would improve it, but you will always get ridges anyway, even if the overall shape is straight, as can be seen on the underside of the button.

Yes that was caused by trimming with a knife - not the printer.

Ah OK, great, one less problem then 

[xrunner]

OK I see... inherent to printing process, crap 

You could just put prime/paint the top of the knob to fill the "crevasses" or whatever the white paint had seeped into. Then sand that down to be smooth. Then make a clean dimple using a cutting tool. Secure the knob in a vice, bring it to the drill press. Don't use a regular drill bit as it will probably make a mess. Instead use one of those bits that have a flat end/face, rather than pointy/conical. I don't know how it's called.... we used on aircraft fitting when a fastener was too close to the radius / pocket edge and the head of the fastener would be prevented from sitting perfectly flat on the fitting surface, hence not doing its job properly. We called it "spot face "IIRC in English on the drawings. Google confirms that, here is a random YT example :

Yes all that is possible. I did just now order Tamiya gloss model paint, both white and black. I do have primer so I will start in with that today or tomorrow on a test button. Heck, since I can print as many buttons as I need, I may go ahead and see what the finish looks like with flat black just for fun.

Let's see where this goes ... 

[DC1MC]

@Vince - your video signal is OK, personally I would check the monitor input, you should have image, eventually with some desync/bars due to the tracking adjustment (most VHS VCRs have a small button hidden somewhere on the front panel labeled "Tracking")
Also see if the monitor/TV expects the standard (SECAM/PAL) that the video outputs, the older monitors were always displaying something, the newer one may keep the screen blank if they don't have the right signal standard.

Cheers,
DC1MC

[factory]

Mouarf.... trying to fix a VCR, first one in my life, never worked on these things before...
It was given to me and I thought hell, would be cool to (try to...) fix it as an exercise and to have at least one VCR around, you never know when you might need one... seeing as I tend to like old stuff, who knows, might come handy one day.

Anyway. First it did not power up at all. Was bloody RIFA. Removed it, works fine now. don't have VHS tapes but the old guy who donated the VCR also donated a tape of Star Wars the Phantom Menace.

Anyway it plays the tape... audio is just fine, I can hear the movie sound track just fine, but no video ! 

I tried using SCART and video composite on two different LCD monitors equipped with these I/O, and every time the same answer : " No sync ", and a black screen, so not happy.

Looked at the schematic, have partial ones, not the main board sadly... but have the one for the rear panel PCB that carries the I/O connectors, and plugs right angle to the mother board.
I see that the video composite signal comes from a chip on this board, and is served to both the RCA jack AND the SCART connector. Apparently SCART has both RGB and composite signals available. I don't know which one the monitors actually use when I ask them to display SCART. Anyway, at least if make some sense that both SCART and composite would not work...

Anyway, I scoped the composite signal on the RCA jack, and to me looks like a I do have my composite signal ?!  So why doesn't it work ?! 

I know squat about video let's be clear.... I simply looked at Google to find diagrams of what it should look like. I have my negative sync pulse, about 5us as it should. Total frame length is about 64µs as measured with the cursors, which is what it should be about. So as far as sync goes, the LCD monitors should be able to detect a signal eh ?! 

My two main worries that might explain the problem (?!), tell me what you think :

- Noise... as you can see from the video clip below and my screenshot, there is lots of noise... but that could just be my probing setup which is more than awful of course, not having a BNC to RCA adapter nor even a coax cable.. so just using my probe in x1 and a little contraption made from recycled RCA jacks. It's too ugly to be showed here, don't want to stoned.

- Looks like there is a HF signal superimposed on everything, whose vertical excursion spans the entire composite signal... looks like faint squiggly lines at the top and bottom of the waveform.  This does not show on wave form diagrams I see on the net.. however I understand there are two combined signals on these things, "luminance" and "chrominance", so maybe what looks like squiggly lines is just one of those two signals and everything is fine . I am so clueless it's painful.

- Voltage levels : 99% of the diagrams I found do NOT indicate voltage levels. Instead they use funny "IRE" units, whatever that means, to give the proportions of the various parts of the signal, but not actual voltages. Proportions look fine on my signal, I find. Video content is about 2+ as high as the sync pulse.
The rare diagrams I found that did indicate voltage levels, showed a 1Vpp excursion, but I get as you can see 2.5Vpp or so ! 

It's so horrible to hear the sound track of Star Wars but not being able to see the video even though I can see it on the scope !!! 

Anyone here with working knowledge of composite signals ? I am in Frog land so I guess we are talking SECAM, though from what I see, SECAM / PAL / NTSC have very similar looking wave forms...

Probably not much help, but I did have a problem trying to get a composite signal out of one of those Scart-to-RCA adaptor blocks, from a Digital TV convertor box, to test an old B/W CRT based CCTV monitor (to prove the camera was broken in the & not the monitor).
Turned out the Scart adaptor I was using was the input type, I eventually figured it out and remembered I did modify one to inside to work as an output type, apparently the composite video signal is on different pins depending whether it's an output or input.


Digital TV convertor box output on the HP 180A (with 1801A/1821A), second picture of the faulty CCTV camera output and I should point out I didn't know what to expect to see on a scope, this was the first time I had ever played with TV signals on a scope, I must remember to try the Tek 2465B (ex-BBC with TV option) sometime.



The only other thing I can think of is the monitor you are using, if it's a regular PC monitor would it get confused by the Secam standard, or maybe just incompatible with TV signals? And if it is a PC monitor, have you got a regular old TV you could try instead?

David

[factory]

today i received a present to myself 🙂 on Dutch ebay 'marktplaats' i bought an Tektronix TDS1001C-EDU   40MHz /500MS/s

turnsout...its brandnew, in an original box with all cd's books 2 100MHz probes original and trim screwdriver... its all there and original.. amazing !
just checked the menu... it says 5 power cycles ))
C version has colorscreen, EDU (for schools) had all this nice software too.. cool

So if one is looking for this EDU software, i can put it online for download.

Oh nice!
If there's anything interesting on those CD's, you should upload to the tekwiki.

Jarid.. 'The Tekwiki' ??  for a none tekboy (for now) .. i google like 20 tekwiki's ?

For me it's the first result when I search for "Tekwiki" https://w140.com/tekwiki/wiki/


David

[m k]

I had once a toploader Fisher and it said PAL/DDR SECAM.
(difference in color only)

Is it copy protected tape?
If so then your LCD may be the reason.

I vaguely remember something CRT TV frame timing stuff.
Something where TV can show it but another VCR can't catch it.
Maybe your LCD is too picky.

Some old VCRs had also an internal test signal.

[Bud]

The rare diagrams I found that did indicate voltage levels, showed a 1Vpp excursion, but I get as you can see 2.5Vpp or so ! 

The output is expected to see 75 Ohm termination. You can switch 50 Ohm termination on your scope as approximation to test the signal level.