Funny enough, when i was doing electronics training they had a test system that would simulate faults on the board for you to trace. As they also gave you a simple scope, function generator, multimeter and assorted test leads, along with nearly a week to play with the system, I actually did manage to find all the simulatable faults they had ( there were 8 CO relay contacts to either short or open parts of the circuit) on there, and set up the system to use itself as a signature analyser, and consistently got a test score of perfect, and a time under resolution of the system ,being able to diagnose and enter the 10 simulated faults they tested you on, with the overall time being 0.0 minutes, as I was able to do each section under the 6 second resolution of the controller. Was a little disconcerting to the instructor, brand new test system, brand new training manuals and us being the first ones to use it. the test was supposed to be an hour long, as the instructors had taken around that time to do it.
They strongly discouraged us from turning the cabinets over, undoing the screws and looking inside, though of course as there were 30 students in the class, all around the room, and one instructor being harried by all and sundry, there was kind of lack of supervision. Z80, 32k of ROM, 2k (6116) of RAM, UART and Z80 PIO, a ULN2003 relay driver, and 8 Omron relays were on the board, along with a RS422 interface to daisy chain it along, and each board had a jumper set for termination. A little bit of logic and a 74C922 keyboard encoder, and some 7 segment decoders and another uln2003 as led drivers for the multiplexed 4 digit 7 segment display, and for the red and green pass/fail LED's on the front panel.
Power supply was a transformer with 3 secondaries, providing +-15V rails for the analogue stuff on the test boards, 12V for the relays and DUT board as well and 5V for the DUT, all being 78/79 series regulators on a common heatsink, and another 7805 for the logic board ( wonder why that was, board ran pretty cool) alone.
They were somewhat surprised at the scores, next lot only saw the system on the test day, rest was theory and practical on breadboards.......
Received these little boards. They allow you to tap into 6P6C or 8P8C connections/lines easily, either to inject a signal or look at one.
Re the Signature Analyser - I like how they can self test by sticking the probe in its test port - were some of the later models also a logic probe as well??
Got this Metex M-3640D for €20 and after a cursory look it seems to be well within spec. Basic 3½ digit meter with TRMS, RS232, nice dispaly, nice features and mechanically well built. I don't mind the missing sticker, or the transistor tester..
Decided to take a chance and ordered a 14mp camera for my stereo microscope. It's one of those blue inexpensive ones on Ebay. Got a 0.5x lens for it. Crossing my fingers that it works ok. Here are the links to them:
http://www.ebay.com/itm/272276903278
http://www.ebay.com/itm/141950389592
I've already got a C-mount camera, but the adapter I bought from AmScope was completely baffling.
I thought this was the right one:
https://www.amazon.com/gp/product/B005PONV98Neither end fits in the 3rd tube for the camera (or the eyepiece holes, either).
And neither end fits a camera C-mount, either.
Yeah, I nearly got caught on that, too. It seems that that adapter has a threaded end that fits in the microscope head instead of the adjustable tube assembly that comes with it. HOWEVER, it only fits some of the models. If you look at the Amscope website for that adapter,
http://www.amscope.com/accessories/adapter/5x-c-mount-lens-adapter-for-microscope-video-cameras.html you can read where it says " *Note: this will not fit the "TP" version of the SM series.*". This includes all of the simul-focal heads and some others like mine.
The SM-XXTP series scopes do NOT accept a threaded adapter. They have a dovetail ring with setscrew that the original adjuster tube that comes with the scope just slips into and is held with the setscrew. Once I realized the difference, I checked my scope and sure enough, it had the dovetail. But mine is not a simul-focal or TP version,
yet it has a dovetail setup. It seems that only a few of the types of heads can take the adapter you linked to. I was not able to find a adapter that would have a dovetail to just be mounted directly to the scope, so I ordered the adapter in the picture above that just slips into the adjuster tube the scope came with. Not ideal, but it's all I can do.
I wish Amscope would have made a page that would have made it more clear. But, they did make a couple of vids on youtube that are handy and one that shows the screw in type adapter and you can see if yours is like that or not.
How to install a AD-C20 adapter (same adapter you have) to a SM microcope.
This one shows how to use, focus, and adjust a SM microscope head. It shows how to set it up so that the image stays in focus through the eyepieces throughout the zoom range and how to use other controls on it.
Bought an Atten 858D+ and it arrived this afternoon - yay!
Got it for a good price (A$95/free postage after a 25% discount voucher from eBay - you beauty!).
It was from a local supplier - well the stock was held locally, but the seller was in Hong Kong, which meant I got it within 2 days.
Straight away I tested the earth connection - surprised to find the case was earthed all around - have the manufacturers lifted their game here?
One 'fault' is the Australian power cable provided does not have the obligatory insulation at the base of the live & neutral pins - I can live with that or I may change it as I have other cables lying around here somewhere.
Have yet to crack it open and inspect the innards for faults (after I revisit Dave's video and the relevant forum threads to remind myself of the possible faults before I fire it up - and as Dave says -
Don't turn it on, take it apart!).
I also ordered a
Multifunction Tester - TC1 but that will be 4-6 weeks wait until I get my hands on that (from China as if you hadn't guessed
).
I could have bought the 'no-frills', sans case, testers much cheaper but I liked the case and the colour screen is cute (but not necessary).
Edit: Bugger! - Forgot about an SMD testing pad
Oh well, it will still be useful (perhaps the SMD pad is on the PCB but just isn't exposed through the case - ever hopeful!).
I bought a camera. Two cameras actually. Two OV5640 camera modules for the two SushiBits L Camera units I plan to build.
Also I bought yet more SRAM and a few CPLDs and other chips for the PC/XT project.
Ooh and I also bought a bunch of Neopixels.
Today's mail:
Item 1: Fluke 8020B in perfectly working condition (is there a way to determine manufacturing date by serial number?)
It came with a pair of Kemmler silicone instrument cables and a pair of Hirschmann test tips.
Item 2: Fluke TL71 test leads, used
Playing together nicely with my purchase before that: The HP 16c.
Also, I started digging into the ESP8266 and built a small web server to go with my Gaggia Classic espresso machine (remotely switch on / off and temperature polling).
You can check the dates on the ICs to get a general idea of when it was built.
McBryce.
So this *might* point to being 1984ish?
Could not find anything useful on the other parts though.
This unit was made in Tilburg, Holland by the way
Mid '84 sounds about right given the 8401 code on the Intersil chip and the 419 (which *might* be a shortened date code) on the nearby RCA part.
-Pat
Today's mail:
Item 1: Fluke 8020B in perfectly working condition (is there a way to determine manufacturing date by serial number?)
It came with a pair of Kemmler silicone instrument cables and a pair of Hirschmann test tips.
Item 2: Fluke TL71 test leads, used
Playing together nicely with my purchase before that: The HP 16c.
Also, I started digging into the ESP8266 and built a small web server to go with my Gaggia Classic espresso machine (remotely switch on / off and temperature polling).
Some nice toys there. I've started collecting Fluke 8000's - they're just perfect meters
I usually date a Fluke by cracking it open and having a look at the IC dates.
Nice
So the 16c and 8020B are both the same age. Basically I could throw a 33.33 years birthday party this summer for them xD
Awesome!
JRC NJZ-2000 (GSM/W-CDMA) Multi System UE Tester.
I have removed all 5 boards (CPU, I/O, DSP, and 2xRF) and put a RPi2 in it.
A very very crowded restoration project. Waterman Pocketscope S-11-A.
Tube produces a spot, didn't dare test it more until I replace the electrolytic and paper caps. Is that square thing a really big paper capacitor!?
(And on closer inspection, one of those tubes is definitely gassy.)
A very very crowded restoration project. Waterman Pocketscope S-11-A.
Tube produces a spot, didn't dare test it more until I replace the electrolytic and paper caps.
Just give it some good time on a dim bulb tester, bit by bit increasing the wattage of the bulbs while watching for signs of things running amuck. Old ecaps have a worse reputation than they deserve. Those on the PSU might be worth testing but the others I'd leave alone until proven otherwise.
HP 3478A. Needs a little cleanup and a new battery but otherwise spot on. Has date codes of 1984.
OK, I decided to be their Guinea pig. I ordered the new Digilent Digital Discovery with a high speed header. Hope it works like they say it does and no horrible bugs infesting it. I guess I'm one of the first 100, as I got the header for free. How new is it? like 11 days since launch.
Since I've never used a logic analyzer before, maybe you folks can help me review it in another thread.
https://blog.digilentinc.com/new-product-announcement-digital-discovery/Since I've never used a logic analyzer before, maybe you folks can help me review it in another thread.
So this *might* point to being 1984ish?
Could not find anything useful on the other parts though.
This unit was made in Tilburg, Holland by the way
There should be an LM358 on the PCB with a date code too.
McBryce.
There should be an LM358 on the PCB with a date code too.
This one features a Signetics CR999NC and a TI SN10091BP as the only DIP8's like LM358.
And there is a DIP14 MM74C00N from National Semiconductors.
The Signetics states »8415« and the NS »P8408« as additional markings. So 1984 seems to be somewhat logical
Regards,
Frederik