Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Good spot. I was looking at his 83732A and it looked hooky.

Hooky as fuck, look at the long list of other items, hundreds of things and weird prices. Quick sale only before people realise their accounts are hacked does seem likely.

From mobile device so predictive text might have struck again [emoji83]

[Specmaster]

Good luck 

I’m doing a kids party today for 5 year olds so no TEA for me 

I think that loaded on the lorry for delivery means, delivery on Monday as parcelforce charge extra for Saturday deliveries so I'm afraid it also means now, no TEA for me either.

From mobile device so predictive text might have struck again [emoji83]

[Cerebus]

Quick sale only before people realise their accounts are hacked does seem likely.

Yup, that's exactly what it looked like to me. I've told ebay and messaged the seller - whether the actual account owner will get to see it is questionable, but at least I tried.

If I thought that there was any chance of getting the City Police's e-fraud boys to wake up and do something I'd tell them too. However, they seem incapable of responding to the e-equivalent of "suspects on premises" in a robust fashion the way the response boys do. Last time I reported one of the latter I got the fun of watching five coppers and a police dog chase a suspect across Stockley Park.

[bd139]

I think that loaded on the lorry for delivery means, delivery on Monday as parcelforce charge extra for Saturday deliveries so I'm afraid it also means now, no TEA for me either.

You might be lucky. I occasionally get a ParceForce delivery land on a Saturday. Usually only their subcontracted drivers though.

If I thought that there was any chance of getting the City Police's e-fraud boys to wake up and do something I'd tell them too. However, they seem incapable of responding to the e-equivalent of "suspects on premises" in a robust fashion the way the response boys do. Last time I reported one of the latter I got the fun of watching five coppers and a police dog chase a suspect across Stockley Park.

CoL e-fraud police are fucking shit. They're in a feedback loop that allows financial crime to take place intentionally by hiring minimally capable idiots to handle investigations. Witnessed it with my own eyes.

Our local police are also shit. Sometimes this goes in your favour like they don't come out when the guy who burgled your shed the second time, because they didn't do it the first time, stands on the plank with lots of nails sharpened with an angle grinder hammered through it or rips off half his clothes on the carpet tack strips on the back fence.

Anyway I survived the two hours of little shits going mental and destroying everything in sight. Most of them are animals! Now to go and fire up the soldering iron and relax.

[tggzzz]

So I powered it up. I do this now with a variac and monitoring the current while.

Ob reminder: don't do that with equipment that has a switched-mode power supply. The constant power output plus low input voltage implies a high input current.

[Neomys Sapiens]

Here we go again ...

After acquiring that boat anchor I resolved to fight GAS and ignore fleabay. This worked amazingly well for two months. It wasn't too hard, even. As a result, I spent my time and money to my other hobbies.      Since my rooms are full enough, I thought it would be easy to stick to it.

Then, last week, I sat in front of my computer, drinking my coffee and idly browsed the web. Nobody knows how I landed at the bay, but suddenly I was there! And then I saw it: a beautiful Philps PM2421 DMM. Reasonable price. How in all the world could I have resisted this? I'm just a weak human, after all! This DMM could not be allowed to go anywhere but my place. Isn't it understandable that I relapsed? I won the auction late Friday night at a still reasonable bid. Although I wire transferred the money within 5 minutes, that thing wasn't sent until Thursday and still hasn't arrived. 

I found a good scan of the manual, and looking at the schematics, it suddenly occurred to me why I might have that sweet spot for Philips.

Our first radio was a Philips Philetta, bought a year before I was born. I remember looking through the perforated cardboard back panel as a kid and being mesmerized by the magical glow of the valves and the mysteries of its operation.
Our first record player was a Philips.
Our first TV was a Philips b&w set. We were the last in the street to own one.
With the first money that I earned myself (a holiday job), I bought a Philips EE2000 "electronics lab".
Now, looking at the schematics all this came back to me. Philips' schematics are my reference. They are just beautiful. Highly skilled draftspersons created pieces of art that really help understanding the function.
Philips may not be revered as HP, Fluke or Tektronix are. But, IMHO, they were not that far behind.

A few minutes ago I saw the DHL van in the street next to mine. Where has it gone? It ought to be in front of my house by now! 

Do you know the two-volume 'Philips Lehrbriefe'? I used them in 2 cases to explain electronics to people that won't get nit otherwise. Especially their transistor explanation was ingenious.
Did you read my post about the PM3088 looking for a caretaker?
Where I am at odds with them are their desk multimeters. Both the PM2519 and the PM2521 have interesting features. But they could not think of combining them. THAT would have neen a nice instrument.

[med6753]

While I'm waiting for the parts to arrive for the Tek 465 I figured I'd revisit the Fluke 8000A DMM drift issue and power supply modifications. In my previous posts on the same subject I was able to show that I reduced overall warm up drift from approx 40mv to approx 20mv on the 20V DC range by installing 7815/7915 linear regulators on the +/- 15V supplies. Through discussions here it was recommended that additional drift reduction might be possible by regulating the currently unregulated +5V supply. So today a modeled a modification and I have the results.

To simulate a “real world” mod I decided to use an actual 7805 regulator. I disabled the unregulated Fluke supply and tacked in the 7805. The 7805 is fed by an external supply of +9V. The output of the 7805 is a steady +5.037V. The results are in the pictures. Pix 1 is right at power on. A steady +10.00V with only an occasional blip to +9.99V. Pix 2 is 1.5 hours later. Again, steady +10.00V with only an occasional blip to +10.01V. Conclusion: Any appreciable drift has been almost completely eliminated and this mod is worth it.    I don't have a suitably sized transformer to fit into the case so I'll have to order one. Once I do that I'll post pictures and a schematic of the modification.       

[Specmaster]

Well done, I wonder why they didn't think about regulating the supply when they designed it then, as you have ably demonstrated it makes a massive difference the accuracy and reliability of the meter?   

[med6753]

Well done, I wonder why they didn't think about regulating the supply when they designed it then, as you have ably demonstrated it makes a massive difference the accuracy and reliability of the meter?   

Perhaps when the DMM was new 40 years ago it was adequate. Now that components have aged perhaps they need a little help. I know 40 years on I certainly do. 

[Specmaster]

Well done, I wonder why they didn't think about regulating the supply when they designed it then, as you have ably demonstrated it makes a massive difference the accuracy and reliability of the meter?   

Perhaps when the DMM was new 40 years ago it was adequate. Now that components have aged perhaps they need a little help. I know 40 years on I certainly do. 

Perhaps, if your 40 and need help, imagine me then I'm 70 and most certainly need help 

[med6753]

Well done, I wonder why they didn't think about regulating the supply when they designed it then, as you have ably demonstrated it makes a massive difference the accuracy and reliability of the meter?   

Perhaps when the DMM was new 40 years ago it was adequate. Now that components have aged perhaps they need a little help. I know 40 years on I certainly do. 

Perhaps, if your 40 and need help, imagine me then I'm 70 and most certainly need help 

I wish I were still 40. Will be 65 this June. Where did the time go? 

[Specmaster]

Well done, I wonder why they didn't think about regulating the supply when they designed it then, as you have ably demonstrated it makes a massive difference the accuracy and reliability of the meter?   

Perhaps when the DMM was new 40 years ago it was adequate. Now that components have aged perhaps they need a little help. I know 40 years on I certainly do. 

Perhaps, if your 40 and need help, imagine me then I'm 70 and most certainly need help 

I wish I were still 40. Will be 65 this June. Where did the time go? 

I don't know but I sure as hell keep looking for that brake to slow time up but still not found it yet. 

[med6753]

My solution for lack of LCD backlight. USB LED goose neck lamp meant for laptop. Can be placed where needed. I have it plugged into a charger supply.

[Mr. Scram]

Good luck 

I’m doing a kids party today for 5 year olds so no TEA for me 

Not sure whether you have very young friends, or have a second career as a clown.

[Specmaster]

That's not a bad idea.

[Specmaster]

Good luck 

I’m doing a kids party today for 5 year olds so no TEA for me 

Not sure whether you have very young friends, or have a second career as a clown.

Called Sideshow bd139?? 

[bd139]

My feet are big enough 

[Specmaster]

My feet are big enough 

Ok, which of us has the biggest feet, mine are sized 14.

[mnementh]

These are “warm white” ones from here: https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=172_367&products_id=3360

Agree entirely about the colour temperature. There too much blue in the non warm ones. Does your eyes in.

Slightly worried about the noise off the cheap switcher. Will fire up my radio and have a listen later.

Exactly, the RGB ones might be an idea as you select a colour or mix your own using the remote control. My LEDS are proper under cabinet fittings my done got his work for me which I think are warm white but not sure as the packaging did not specify.

From mobile device so predictive text might have struck again [emoji83]

You want "Warm white" LEDs advertised in the 4500-5500 range to get something between old blue-fluorescent and incandescent lighting. LED lighting is evil on a test bench, especially RGB as it's all controlled by poorly-approximated PWM from the cheapest COB processor they can manage. Be prepared; it generates HUGE amounts of common-mode noise that will drive you batshit crazy while you work.

Even plain white LEDs powered from a cheap SMPS make a lot of noise as the light strip is a huge antenna; the best, most tolerable setup I've gotten so far is to power them from an old linear wall wart with a couple 4700uf caps across the output and 1uF ceramic across the rectifiers.

You have been warned,


mnem
*Lit*

[bd139]

Actually I fired it up and it's silent on 20/40m at least (7/14MHz). Was quite surprised.

My feet are big enough 

Ok, which of us has the biggest feet, mine are sized 14.

Ok you win, only just

[Specmaster]

These are “warm white” ones from here: https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=172_367&products_id=3360

Agree entirely about the colour temperature. There too much blue in the non warm ones. Does your eyes in.

Slightly worried about the noise off the cheap switcher. Will fire up my radio and have a listen later.

Exactly, the RGB ones might be an idea as you select a colour or mix your own using the remote control. My LEDS are proper under cabinet fittings my done got his work for me which I think are warm white but not sure as the packaging did not specify.

From mobile device so predictive text might have struck again [emoji83]

You want "Warm white" LEDs advertised in the 4500-5500 range to get something between old blue-fluorescent and incandescent lighting. LED lighting is evil on a test bench, especially RGB as it's all controlled by poorly-approximated PWM from the cheapest COB processor they can manage. Be prepared; it generates HUGE amounts of common-mode noise that will drive you batshit crazy while you work.

Even plain white LEDs powered from a cheap SMPS make a lot of noise as the light strip is a huge antenna; the best, most tolerable setup I've gotten so far is to power them from an old linear wall wart with a couple 4700uf caps across the output and 1uF ceramic across the rectifiers.

You have been warned,


mnem
*Lit*

Problem is that over here in the UK we are being driven into using LEDs for all our lighting or florescent as it now illegal for shops to sell incandescent light bulbs anymore. Its all part of the UK governments commitment to the Paris Agreement that your President Chump threw out. So we have horrendous amounts of radio interference these days, AM radio is almost useless unless out in the middle of field somewhere.

[Specmaster]

Actually I fired it up and it's silent on 20/40m at least (7/14MHz). Was quite surprised.

My feet are big enough 

Ok, which of us has the biggest feet, mine are sized 14.

Ok you win, only just

Ok, I won something yippee, let me tell you though that the old wives tale relating the size of mans feet is utter bollocks, sadly

[Specmaster]

These are “warm white” ones from here: https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=172_367&products_id=3360

Agree entirely about the colour temperature. There too much blue in the non warm ones. Does your eyes in.

Slightly worried about the noise off the cheap switcher. Will fire up my radio and have a listen later.

Exactly, the RGB ones might be an idea as you select a colour or mix your own using the remote control. My LEDS are proper under cabinet fittings my done got his work for me which I think are warm white but not sure as the packaging did not specify.

From mobile device so predictive text might have struck again [emoji83]

You want "Warm white" LEDs advertised in the 4500-5500 range to get something between old blue-fluorescent and incandescent lighting. LED lighting is evil on a test bench, especially RGB as it's all controlled by poorly-approximated PWM from the cheapest COB processor they can manage. Be prepared; it generates HUGE amounts of common-mode noise that will drive you batshit crazy while you work.

Even plain white LEDs powered from a cheap SMPS make a lot of noise as the light strip is a huge antenna; the best, most tolerable setup I've gotten so far is to power them from an old linear wall wart with a couple 4700uf caps across the output and 1uF ceramic across the rectifiers.

You have been warned,


mnem
*Lit*

By the way, I PM'd you did you get it?

[nixiefreqq]

fat lot o' good being a member of this group did me!

swore an oath never to buy another nixie counter.

but decided to attend the fest over in york this morning and spotted this 5221a.

never would have touched it (honest!).....but had never seen one in a carry case before. (already have 2 each working 5221b's)

was about to put it back in its proper place when the guy snuck up behind me and whispered "5 bucks".   

damit!  i am only human after all.

had to wiggle the boards to get it counting.  but now it won't stop.

only 5 digits and 1Mhz.   

what is it goood for?  aaaabsolutely nothin'!

but it sure is cute.


ps  asta and i may both be sleeping in the garage if swmbo spots it. 

[GerryBags]

ps  asta and i may both be sleeping in the garage if swmbo spots it.

Asta's pretty cute too. You'd swear those eyes were saying: "You know you're in trouble, don't you?"