Products > Test Equipment
Test Equipment Anonymous (TEA) group therapy thread
med6753:
--- Quote from: grizewald on July 17, 2022, 04:10:56 pm ---More Datron 1071
As I said in my last post about this meter, there's no such thing as a perfect one when you're talking about something from the mid '70s.
Mine was no exception, and although the meter powered up straight away when I received it and seemed to give plausible results when
reading a few voltage references and precision resistors, it was obvious that the meter wasn't entirely happy. First task was to check the
infamous Philips blue electrolytics.
Sure enough, with one end freed from the PCB, they measured:
Des. Printed Actual ESR
Value Value
C45 47μF 34μF 8.1Ω (Furthest away in the photo)
C46 47μF 34μF 6.4Ω
C47 33μF 28μF 8.1Ω
C48 33μF 25μF 10.2Ω
C49 10μF 9.7μF 4.5Ω
C50 10μF 9.4μF 7.6Ω
The replacements from Kemet and Vishay were a bit of a squeeze, but had rather better parameters:
Des. New New
Value ESR
C45 50μF 0.22Ω
C46 49.7μF 0.22Ω
C47 32.2μF 1.38Ω
C48 31.5μF 1.44Ω
C49 11.7μF 0.55Ω
C50 11.7μF 0.55Ω
I then checked the various power rails and found out of tolerance voltages and excessive ripple,
so it was time to turn my attention to that area of the meter. This is where the fun starts!
The power supply is implemented on the board that runs across the rear of the meter. Between that and the
rear of the case, Datron also crammed in all of the boards that handle the optional outputs, the front/rear
relays and the two stacked toroid transformers. It's kind of packed in there as you can see from
the photo below.
The only way I could easily work on the power supply was to separate the rear of the case with all its
boards from the rear PCB and remove the analogue, digital and current boards so that I had clear access to the
solder side of the PSU. I wasn't keen on my chances of being able to put it all back together again without
extensive photo documentation of what plug went where - there are no identifying labels on any of the plugs
that connect everything together, so I took my time and took many photos along the way. Finally, the rear
of the case was free!
continues in next post (which will be after I've eaten some strawberries and cream )...
--- End quote ---
Philips CRAPacitors are also very common in Fluke equipment and are to be shot on sight without trial. >:D
Robert763:
--- Quote from: mnementh on July 17, 2022, 03:11:54 pm ---
--- Quote from: Robert763 on July 17, 2022, 02:22:20 pm ---
--- Quote from: mnementh on July 17, 2022, 02:03:45 pm ---
--- Quote from: Robert763 on July 17, 2022, 09:48:17 am ---
--- Quote from: Robert763 on July 16, 2022, 07:19:59 pm ---New TEA
What could it be?
--- End quote ---
It's a General Radio 2220 Bug Hound. Used for tracing shorts and opens in PCBs and wiring. also good for genearl circuit tracing.
Unlike similar tools like ToneOhm and the HPP current tracer probe it uses AC signals and a phase sensitive detector. I'm looking forward to using it in anger.
--- End quote ---
So non-contact, or just very tiny current so as not to blow up stuff like the ShortSqweek and Huntrons?
mnem
:popcorn:
--- End quote ---
Both.
Non-contact probe with LEDs to show current direction and contact with +- 50uV or 500uV
--- End quote ---
Ooooooh... does indeed sound like the PCB debugging Holy Grail. I can see why you're so pleased to find one. :-+
*adds another "must-have" to his watchlist... and slides it right up to the top*
mnem
Damn you Robert! Damn you to... New Jersey!!! :-DD
--- End quote ---
Already been to New Jersey, more than once. I lived and worked in (old) Jersey Channel Islands for a while.
Just to annoy you more I paid £21.37 including shipping for it ($25.35 US) >:D
mnementh:
My condolences and *shakes my fist* :rant: You lucky bastard! :-DD
mnem
:-/O
mnementh:
--- Quote from: Specmaster on July 17, 2022, 06:52:32 pm ---
--- Quote from: Cerebus on July 17, 2022, 05:32:26 pm ---
--- Quote from: Specmaster on July 17, 2022, 04:32:44 pm ---That's about it, it's like, at least in the UK, it is not illegal for someone to park their car on your driveway, but it is illegal for you to remove it or damage it in any way :wtf:
--- End quote ---
Wrong in almost every important respect. It is unlawful for someone to park on your driveway(tort), it is not unlawful to have said vehicle moved on private property, but becomes illegal the moment on is on public property unless one is properly licensed to do so or is a bailiff acting under court order, or anyone acting under the directions of a police constable or traffic warden (RTA), it is unlawful to damage it in so doing (tort), but recent precedent shows that it is not illegal to damage it in doing so (https://www.bbc.co.uk/news/uk-england-tees-60260155). It is illegal to clamp or otherwise immobilise a vehicle on private property except by closing a gate or barrier that was present but not closed when the vehicle was parked (Protection of Freedoms Act 2012 S.54).
--- End quote ---
Well, that is what I was told by a serving police officer, who was on duty at the time and was attending an incident when that actually happened to me a neighbour who was being a right entitled idiot because he had his family had 5 vehicles to park >:D
--- End quote ---
Part of me wants to say "Take it out of gear and release the parking brake, then let nature take its course..." but no doubt it would be A) seen by witlesses and 2) the driveway would either be too flat for the car to roll the way intended without being pushed the entire way or worse, would slope the wrong way and the car would crash into your house. :-\
(Yes, for the purpose of this self-indulgent fantasy I am ignoring the prevalence of gearshift and steering wheel interlocks.)
mnem
*toddles off to get some urethane*
Cerebus:
--- Quote from: Specmaster on July 17, 2022, 06:52:32 pm ---Well, that is what I was told by a serving police officer, who was on duty at the time and was attending an incident when that actually happened to me a neighbour who was being a right entitled idiot because he had his family had 5 vehicles to park >:D
--- End quote ---
Relying on a serving police officer as a reliable, accurate source of legal knowledge is perhaps not the best course of action, especially as what they tell you is usually dictated by "What should I say to get this plonk arrested/out of my hair as quickly as possible?".
The Police and Criminal Evidence Act 1984 actually requires a person who isn't "a constable" to have a better knowledge of what is and isn't a criminal offence and what kind it is than "a constable" to effect a lawful arrest (section 24 versus section 24A arrests). It's damning when the law formally expects a layman to be better legally educated than a policeman. :)
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