Test Equipment Anonymous (TEA) group therapy thread

[Robert763]

While aimed at their conversion products, this is a good primer on LVDTs, RVDTs, Resolvers and Synchros
https://www.ddc-web.com/en/download/9/documentation
 
Note that they generally converte a 3 wire synchro signal to a 4 wire resolver signal with a Scot-T transformer before converting. Newer systems tend to digitise the 3 synchro signals and do the math as ADCs and miicroprocessors have improved and got cheaper.

[med6753]

Not in Oz, it wasn't, both "B+boost" in tube designs & overwinds on solid state EHT trans were more common than any other way of doing things.

I should have been more specific. I was referring to vintage vacuum tube designs. Yes, some did have an extra B+ Boosted supply originating from the flyback. If I recall that became somewhat necessary when TV's started going cheap by employing series string and elimination of the power transformer.   

Now when TV's started going solid state all bets were off. All sorts of creative designs were employed.

North American and 220/240V countries differed greatly in their approch to valve / tube TV design. In NA they typically had a mains trandformer supplying different voltages. In the UK at least thwy were transformerless designs with a "hot" chassis connected to mains, Filaments in trings with dropper resistors in series and multiple voltages generated from the flyback transformer. They were a significant hazrd to work on 

We had the same design, especially with portable TV's. Series string filaments and a hot chassis just like the "All American 5 tube radio". Worked on many of them without an isolation transformer. 

Ungrounded VTVM's and sometimes a scope. Somehow I survived. 

[Specmaster]

I apologise for being absent from last nights Discord session (again ), I had purchased one of those doorbell video systems and despite having a Wi-Fi router and 2 other WAPs located at various locations in the house I was unable to get a strong enough signal at the front to ensure proper operation of the video system, so I was tinkering around with it trying to get a WAP closer to it and failing.

In the end I gave up and ordered a power link based WAP that I can plug into a power socket right by the door that I had installed some years ago when the kids were little to power outside Xmas lights. Amazon delivered it this morning  and now I have a good signal at the bell push/camera location and it works just fine  .

The total cost came in at about 50% of the comparable RING system all in, just the doorbell video system on its own was 30% of the RING price and there is no annual subscription fee for remote access to the system, including 2 way speech with visitors from anywhere with internet access, so in Dave's words, its a "winner winner chicken dinner." 

[mnementh]

Exploring the capabilities of the Type 503...

Even though it only has 1 vertical channel it has the capability of going into full XY mode. By turning the Horizontal Display knob full clockwise the horizontal sweep is disabled and the scope enters XY mode. The Horizontal (Y) has a set of controls on the lower right identical to the Vertical (X) on the left. The 2nd pix is a sine wave and a triangle wave of equal frequency and amplitude with the resultant waveform.

   

With it's differential inputs and it's XY capability this scope can be quite useful. The only downside is it's bandwidth. 450kHz which is pitiful compared to today's offerings. But it has an ace up it's sleeve. The trace is absolutely magnificent. Laser sharp. The best I've ever seen bar none. It even beats the Type 535A which is no easy feat. And DSO's aren't in the same league. But this scope would be an excellent addition to any audio lab. With the differential input and sharp trace any stage to stage distortion in an audio amplifier is going to show up like a lump of bird shit on a windscreen after you smeared it by turning on the wipers. It will keep an audiophool busy for weeks.     

Yeah... and this was the golden age of Tek, when they were very conservative with their ratings. I wouldn't be surprised if this one will go well into the MHz before the results become meaningless.

That's a gorgeous screen... and that's just how I felt when I first fired up my 54645A. Pics look amazing, and they still don't do it justice. 

Hope you two have many happy years together. 

mnem
And the kids will be ... well, they'll be somethin'.

[mnementh]

I apologise for being absent from last nights Discord session (again ), I had purchased one of those doorbell video systems and...

   

I do NOT apologize; I was up to my elbows in icing and gumdrops. 

No parents were harmed during the making of these gingerbread structures; although Mr & Mrs TinkerDwagon were greatly inconvenienced. But it was totes worth it to see the boi with icing on his eyebrows.

mnem
Is it just me, or does that one gingerbread guy look like "Broccoli the Clown" doing jazz-hands...?

[Specmaster]

@mnem
I have a similar microscope to that one and I also found it very difficult to use at times because the metal base gets in the way of larger PCBs, or the PCB tilts because the base is raised etc and also very hard to avoid touching the tip with the soldering iron, hot air gun or just normal tools etc. I played about with it because my bench is a repurposed office desk with a full width monitor shelf I came with the idea of mounting the scope on that and using the video feed to my PC so the display come up on my monitor, far larger than the 5" scope screen.

I took apart the scope stand and reassembled it in the fashion as shown in the photo below and using a couple of small clamps, can now clamp it to the monitor shelf, upside down and now have at my disposal (depending which way I clamp the base), from about .5" to 5.5" or with it mounted on the shelf with the elevation post swung round 180 degrees, 8.5 to 13" working distance is possible. The ring light is one I sourced from eBay for 1p plus about £3 postage from China, it comes with mains adaptor and a dimmer unit and it vastly improves lighting on the work piece and removes the glare and reflection of the scopes built-in lights. If you don't have a monitor shelf, it is a fairly easy woodwork project to knock something up to act as an elevator for the scope.

[mnementh]

Yeah, I toyed with the idea of doing something like that for like 30 seconds. 

But once I saw the HD7 for only ~$90, and saw that it appears to be pretty much twice the scope in every significant aspect, I decided the difference just was not worth it, as the really important problem remains: just plain inadequate magnification at sufficient elevation from the work to be able to get in there with a hot air nozzle.

I'm hopeful that this different headend will have more usable magnification overall; even holding the objective by hand at the best available angle & elevation, at any elevation high enough that the objective doesn't severely obstruct workspace, the magnification is just marginally usable at best. I'm not planning to actually send the cheaper one back until I have a chance to try them side x side tho.

The difference for me may be this project itself: The object I'm trying to resolve is one of the tiniest chips I've ever tried to work with (2.1mm across), and the actual solder pads are approx 0.1-0.2mm across. The screencap above was taken with the objective ~20mm from the work. There's really no way to get in there and work at all.

mnem
 

[Specmaster]

With my system, that small chip (2.1mm across) could fill almost half of my 23" monitor with something like 10" of work space between the PCB and the scope lens, more than sufficient working space at a fraction of the cost.

[med6753]

Exploring the capabilities of the Type 503...

Even though it only has 1 vertical channel it has the capability of going into full XY mode. By turning the Horizontal Display knob full clockwise the horizontal sweep is disabled and the scope enters XY mode. The Horizontal (Y) has a set of controls on the lower right identical to the Vertical (X) on the left. The 2nd pix is a sine wave and a triangle wave of equal frequency and amplitude with the resultant waveform.

   

With it's differential inputs and it's XY capability this scope can be quite useful. The only downside is it's bandwidth. 450kHz which is pitiful compared to today's offerings. But it has an ace up it's sleeve. The trace is absolutely magnificent. Laser sharp. The best I've ever seen bar none. It even beats the Type 535A which is no easy feat. And DSO's aren't in the same league. But this scope would be an excellent addition to any audio lab. With the differential input and sharp trace any stage to stage distortion in an audio amplifier is going to show up like a lump of bird shit on a windscreen after you smeared it by turning on the wipers. It will keep an audiophool busy for weeks.     

Yeah... and this was the golden age of Tek, when they were very conservative with their ratings. I wouldn't be surprised if this one will go well into the MHz before the results become meaningless.

That's a gorgeous screen... and that's just how I felt when I first fired up my 54645A. Pics look amazing, and they still don't do it justice. 

Hope you two have many happy years together. 

mnem
And the kids will be ... well, they'll be somethin'.

When I do the calibration/compensation I'll do some quick response checks and see how far out she'll go.

And before I'd let an audiophool anywhere near this scope I would weld the covers shut so he can't rob the Bugle Boys. 

[DC1MC]

Having some fun with TE and another device:

https://cb.wunderkis.de/wk-pub/what.mp4

What's that device?

The device is clearly a synchro, but your Tek AFG is way cooler than my AWG, and probably 12 kilo less  . Can't wait to see it  ! !!

Cheers,
DC1MC

[med6753]

Forgot to include this. Description from the 1964 Tek Catalog.

(And notice the UC "K" in the title.  )

[mnementh]

With my system, that small chip (2.1mm across) could fill almost half of my 23" monitor with something like 10" of work space between the PCB and the scope lens, more than sufficient working space at a fraction of the cost.

Yeah, nothing like that with this one. At maximum elevation of 100-120mm you can get in there and work... but then the actual magnification is approx 300%. Magnification vs resolution is where this one falls down. Sure you can make the image big (32" screen here), but then there would be a net of like 6 pixels of actual sensor resolution per solder pad. That's still pretty useless.

To get useful magnification, the objective needs to be 10-30mm from the work; then the damn thing is just in the way. 

mnem
ANNOYANCE! 3 orders from the last 3 days supposedly going to be here today... all show shipped, but none actually "Out for Delivery" and it's after noon.

[Specmaster]

With my system, that small chip (2.1mm across) could fill almost half of my 23" monitor with something like 10" of work space between the PCB and the scope lens, more than sufficient working space at a fraction of the cost.

Yeah, nothing like that with this one. At maximum elevation of 100-120mm you can get in there and work... but then the actual magnification is approx 300%. Magnification vs resolution is where this one falls down. Sure you can make the image big (32" screen here), but then there would be a net of like 6 pixels of actual sensor resolution per solder pad. That's still pretty useless.

To get useful magnification, the objective needs to be 10-30mm from the work; then the damn thing is just in the way. 

mnem
ANNOYANCE! 3 orders from the last 3 days supposedly going to be here today... all show shipped, but none actually "Out for Delivery" and it's after noon.

Oops, yeah I think my memory was playing tricks on me, so I checked. This is an actual size image of a 6mm square tactile push button on my monitor at with 5.5" of space between scope and work plane. So yes, you're correct, 2.1mm would be at reduced working space. My scope is 1080p one, what is yours?

[mnementh]

Yup 1080P, but only to the LCD. Out to the PC is interpolated to 720P max. No, I dunno why.   I expect similar with the new one, which is also rated at 1080P.

I'm just hoping the actual magnification level is a wee bit higher. I dunno if that can be changed in any material way by adjusting the lens focal length; my fear would be that any appreciable increase in magnification would also be out of the usable range of the zoom focusing assembly.

mnem
 

[mnementh]

THIS is New...

     
UTG962E US$127 + $20 new user coupon; this is my BG affiliate link

Of all the packages I was expecting today, the first to arrive was my UTG-962E Arb from bang-em-good, which they still estimate delivery somewhen around the middle of January. 

I realize this is just some weird artifact of the two devices and the two signals together; I did try 1MHz/10MHz signals at the same time deliberately to SEE what weirdness might happen with the generator, but I never suspected there might be anything programmed into the 54645A that could even imagine a reading in the GHz range. Huh.

Quickly playing with it, the UI is pretty straightforward and intuitive, aside from the confusing nature of their use of commas after the decimal. I like that you always have a small icon showing what the other channel is doing, and I like that you can select a channel to modify without enabling the channel; to enable it, you press the CHx a second time and it illuminates, indicating output.

I'm not expecting lab grade output from this thing, and there are some weird limitations on what one can do with both channels active (mostly frequency vs waveform limitations), so of course there is a price you pay for the low, low price you pay. But definitely good enough for hobbyist use, and I love that it's designed to fit so conveniently in this otherwise unused space. I expect it should be plenty to use for diag-ing my 4070A, which is lab-grade. I have yet to play around with the counter function; I'll update here if I find anything extraordinarily good or bad aboot it.

It powers from a 5V/2A external SMPS; users in the relevant thread report that it is of better quality than most cheap Chinese wall-warts, and that the noise floor is unexpectedly low given the price, especially considering it produces +/- 15V rails from that 5V using a on-board SMPS: https://www.eevblog.com/forum/testgear/uni-t-utg932utg962-200msas-function-arbitrary-waveform-generator-220394/

The two black cables came with it; the blue one I made using my cheap RG58 crimpers from a couple months ago.

For those who were interested in those cheap crimpers: Short version is they align pretty well for cheap stamped steel and sintered-metal dies, the crimp was clean and well-formed as expected.  Not best pleased with the ends that came in the kit; while the center hole is the correct diameter, the barb is too fat to fold the braid back over the sheathing and crimp both sheathing and braid.

I was able to get a good crimp by skinning the blue Pliovic sheathing off to just the right length and pulling the braid up over the barb, then crimping with only the braid between the ferrule and the barb. Also, the center pin of these connectors are too brittle for crimping; I had to solder. The cable seems to work well up to the 30MHz max of the UTG-962E; no idea how badly I've affected the capacitance and reflected signal of that BNC at higher frequencies.

Looking on the intardnet, it appears this is exactly the way these are commonly used for HDTV and security cam installs... blearrghh.

https://youtu.be/ktQVwfo-s9w

A'aight... time for me to sit down and write my dad a letter for Christmas.

See all y'alls when I have some actual news on the microscope & iPad/Tristar repair.

mnem
 

[beanflying]

This is how ALL test gear should be shipped  To hot in the shack at 40+C to play with the contents until later 

Problem of how to pack it for a Calibration trip pre solved.....

[Neomys Sapiens]

I do have one PC with a spinny drive and a CD in it other than that the others have SSD's and somewhere I have a plug in CD reader but where  Apart from some ancient backups and photos I should add to my NAS at some time CD's time is about passed.

I thought everyone still had CD/DVD drives in their computers?? Mine is in the bay below the 5.25in floppy drive... Oops.

McBryce.

Seriously, all of my computers do indeed have a CD/DVD drive. It still comes in handy every once in a while. 

I was serious about the 5.25 drive too! As I do a lot of classic computer repairs (Commodore 64, Atari XL, Amstrad CPC etc) I still need 3.5in and 5.25in drives on occasions. I have a separate WinXP computer for the "retro work" which still supports direct read/write to these devices. My main computer with Win10 couldn't access them properly. The XP also has the option of connecting a rather rare 3in floppy drive too if needed.

McBryce.

Ha! I've got one of those too! But I've forgotten what it was needed for originally.

[0culus]

Well, I had me a very interesting TEA weekend. I picked up not one, but two 575 Mod 122C curve tracers and scope mobile carts. Exhausted so some pics tomorrow probably. The price you ask? Well the fellow wanted them gone so the price was right...free.

[med6753]

Well, I had me a very interesting TEA weekend. I picked up not one, but two 575 Mod 122C curve tracers and scope mobile carts. Exhausted so some pics tomorrow probably. The price you ask? Well the fellow wanted them gone so the price was right...free.

Two 575's for free?? You suck!  And "too tired" even for a teaser pix? 

All sorts of rules violations here.



That's one hell of a score! 
 

[0culus]

Well, I had me a very interesting TEA weekend. I picked up not one, but two 575 Mod 122C curve tracers and scope mobile carts. Exhausted so some pics tomorrow probably. The price you ask? Well the fellow wanted them gone so the price was right...free.

Two 575's for free?? You suck!  And "too tired" even for a teaser pix? 

All sorts of rules violations here.



That's one hell of a score! 

Just for you med, then I gotta go pass out. Long day.  The one on the right definitely has step generator issues; no step and there's a permanent +/-16V bias between the base and the collector or emitter just waiting to burn something up. Works fine with diodes though. Have not tested the one on the left but it is practically spotless with no dust at all inside.

[med6753]

Well, I had me a very interesting TEA weekend. I picked up not one, but two 575 Mod 122C curve tracers and scope mobile carts. Exhausted so some pics tomorrow probably. The price you ask? Well the fellow wanted them gone so the price was right...free.

Two 575's for free?? You suck!  And "too tired" even for a teaser pix? 

All sorts of rules violations here.



That's one hell of a score! 

Just for you med, then I gotta go pass out. Long day.  The one on the right definitely has step generator issues; no step and there's a permanent +/-16V bias between the base and the collector or emitter just waiting to burn something up. Works fine with diodes though. Have not tested the one on the left but it is practically spotless with no dust at all inside.

Much better. You are forgiven.  Now go to bed and get some rest.

[mnementh]

TinkerDwagon Quickie: Jiusin DM3 Full HD Digital Microscope:  https://www.amazon.com/gp/product/B07D9FK8LW    
(SNIP)


Quality of the 4.3" screen is actually quite impressive; it is crisp and clear and I certainly believe the claims that it is a 1080P screen. However, magnification simply is not great enough; in order to mostly fill the screen with that 2.1mm chip, the objective is ~20-30mm above the work. There is barely room to get a bent soldering iron tip in there, and no room at all for a hot air nozzle. With objective elevated to 90% of max or so, there is room to reasonably get in there with a nozzle. At that height, the chip measures approx 6.6mm across on the screen; I'll let you do the math as to what the effective diopter is. It simply is not nearly clear enough on either its own screen or the live video app, which displays max 1280x720 res.



Here's a screencap of what it put out at 30-50mm elevation. I toyed with the idea of 3DP-ing something to make a hinged base for the thing, so it would swing back that way properly... but looking again on Amazon, I found a similarly specced 7in model for CAD$113/US$90, or CAD$43/US$35 more.




It has a larger hinged base, and is supposedly 2x the magnification.     https://www.amazon.com/gp/product/B07XVC1LWB

For CAD$112/US$90 , even if the magnification is identical to this one, it will be worth it for the usability factor. It's on its way; should see it tomorrow.

mnem
*toddles off to ded*

This one's a keeper, I think. The different design means I can push the whole objective up in the elevator cradle like this, so none of it protrudes below the metal bracket, which means no worries aboot accidentally touching it with the hot air handset. 

I'll probably print up a ring spacer to make it easy, and to support some auxiliary lighting. As you can see here; with the elevator angled back just a wee bit, the reflection glare goes away and  I can get in there easily with elevation at ~80mm. Magnification at 80mm is approx the exact same as the other one was at 20-30mm. 



Resolution to the PC doesn't seem as good as the other one at 20-30mm; not as crisp. But it is still more than good enough I think.

Overall, this 'scope has much better usability. 

Difference is this one is made to work on stuff, while the little one is just made to look at it. 

Only real negative is that mine arrived kicked to shit and damaged; the base and the elevator rack were sent loose in the bottom, and the box was all bashed in before it was packed, as no damage to the shipping carton. This caused the heavy base and elevator extrusions to bash against each other in many places; lots of dings in the edge of the frame and in the teeth of the elevator rack.

I've taken photos from the first I saw the box smashed; I'm going to contact the vendor and see if I can tap him for a few bucks refund rather than ship it back. I l know I can clean up the teeth in the rack and make it smooth again; I just shouldn't have to, nor should I have to put up with the base being all dinged to Hell.

A'aight... I have a lot of work to do before I can play with this thing... approx 1100 pics need to be optimized and dropped on CF cards for photo frames going out to family this Christmas. I'll let all y'alls know if I have any luck fixing the iPud when I can get back to it.

mnem
*toddles off to ded*

[mansaxel]

I was able to get a good crimp by skinning the blue Pliovic sheathing off to just the right length and pulling the braid up over the barb, then crimping with only the braid between the ferrule and the barb. Also, the center pin of these connectors are too brittle for crimping; I had to solder. The cable seems to work well up to the 30MHz max of the UTG-962E; no idea how badly I've affected the capacitance and reflected signal of that BNC at higher frequencies.

Looking on the intardnet, it appears this is exactly the way these are commonly used for HDTV and security cam installs... blearrghh.

We've got a couple 100000 of those at work.  It used to be so, that due to the better mechanical properties of 50Ω BNC connectors, it was common practice to use them with RG59 and other 75Ω cables. There were "broadcast" BNC plugs made with the right dimensions for the cables but with 50Ω coupling parts.  (The BNC, as we recall, mates across impedances without mechanical harm, unlike the N where this is a cardinal sin). This practice was ended about 15 years ago with the introduction of HD-SDI, i.e digital broadcast quality HD Video over BNC connectors. The disturbances from such impedance bumps as were created by the wrong connector were too much of a reliability issue. 

Now, most really modern broadcast equipment tends to have a SFP+ cage. The use of the BNC is slowly becoming a legacy practice. Analog video transmission is already completely legacy for the most part in my world. It lives on in the synchronisation, which still largely obeys the restrictions of the CRT.  (And no, the Canal & River Trust is not writing the rules here!)

[Robert763]

I was able to get a good crimp by skinning the blue Pliovic sheathing off to just the right length and pulling the braid up over the barb, then crimping with only the braid between the ferrule and the barb. Also, the center pin of these connectors are too brittle for crimping; I had to solder. The cable seems to work well up to the 30MHz max of the UTG-962E; no idea how badly I've affected the capacitance and reflected signal of that BNC at higher frequencies.

Looking on the intardnet, it appears this is exactly the way these are commonly used for HDTV and security cam installs... blearrghh.

We've got a couple 100000 of those at work.  It used to be so, that due to the better mechanical properties of 50Ω BNC connectors, it was common practice to use them with RG59 and other 75Ω cables. There were "broadcast" BNC plugs made with the right dimensions for the cables but with 50Ω coupling parts.  (The BNC, as we recall, mates across impedances without mechanical harm, unlike the N where this is a cardinal sin). This practice was ended about 15 years ago with the introduction of HD-SDI, i.e digital broadcast quality HD Video over BNC connectors. The disturbances from such impedance bumps as were created by the wrong connector were too much of a reliability issue. 

Now, most really modern broadcast equipment tends to have a SFP+ cage. The use of the BNC is slowly becoming a legacy practice. Analog video transmission is already completely legacy for the most part in my world. It lives on in the synchronisation, which still largely obeys the restrictions of the CRT.  (And no, the Canal & River Trust is not writing the rules here!)

The text in red above is not correct! Modern 75 BNCs will mate with 50 ones without damage because they use the same center pin with reduced dielectric for matching - sort of.
TRUE 75 BNCs have reduced center contact diameter and will not mate correctly with 50 BNCs putting a 50 Male into a 75 Female will spread the contacts on the female. The other way round is likely to produce a poor contact depending on the exact type of Female contact design.

[Zucca]

https://www.bendijkman.nl/

If you could set GIMP to save forum uploads as JPG's that would help those of us that use pay-as-you-go on their phones. 

Sooo close!

Many thanks David

Input:



Output:



do not worry, the transparent areas are there, just not in the jpg.

Now I have to find someone who can print this. For the records it is a Philips F5X12A/19 model.

PS: GIMP is fantastic for me, bye bye Adobe....