Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

https://www.asciipr0n.com/pr0n/pinups/pinup00.txt (nsfw) 

I still have some paper version of those, buried somewhere.

The best was a nightview of the iconic GPO (now BT) Tower in central London. To get adequate darkness there was several layers of overprinting. I'm mildly surprised the paper survived intact.

[tggzzz]

Just a heads up for those in the UK that have GAS and like geek porn.

There's a voltnut meetup in Cardiff on Sunday, as per https://www.eevblog.com/forum/metrology/voltnut-meetup-in-cardiff-wales-this-sunday-(june-9)/

[bd139]

I've still got a bag somewhere. Like hell they were BC108s 

UMUT = UnMarked UnTested = shit!

Edit: had a bag. Just realised I chucked the damn things in a bin.

Yeah, but they were affordable back then. Besides if they had an h_FE>10 they would have worked in most of my circuits!

I threw away some of those 'orrible enormous mustard capacitors, before I used fleabay and saw the prices audiofools were paying for them

They were pretty expensive I found. Basically because I hauled my butt all the way from Stortford to Ware on a bus to go there and found that the result was a wasted day and a bag of disappointment. I shopped at cirkit after that even though the bus journey was just as horrible. My grandfather lived in Ware so this was an attempt at getting a free lunch which turned out to be horrid because he was old and confused and got the dog sausage mixed up with the other sausage and fortunately did a last minute swap back to human grade food. Uck.

[tautech]

OT
Something for Bean and mnem that we discussed a good while back.
Finally finished the dry run protection on that new pump installed back in Feb. 
$12 flow sense switch plus a $1 timer chopped/hacked/cleverly installed  into the 12V pump control circuitry so that the pump will only run for 2s without sensing water flow.
Bonus visual feedback in that the ON light atop the pump shed power pole indicates the NO flow by going OUT/OFF when the NO flow sense triggers.
That's put that chapter to bed until the next stuff up happens. 

[VK5RC]

@tautech - like the hack 

As if I don't have enough HH DMMs, a Brymen 869s jumped into my 'basket' after reading some of joesmith's HV pulse testing - not that I need HV pulse resistance mind you, but my ability to stuff up is legendary! 

Also have bought another rack 1.8m H x 1.5m W x 0.5m D  to put behind my desk unit to beef up the current shelving 

[tautech]

@tautech - like the hack 

I did too when I finally got my foggy brain around the logic of it all. 
Had to have a break and clear the brain before I could get it to work as I wanted. 
I had 2 lots of NO/NC contacts to work with, 1 set in each of the flow switch and the timer that when powered switched its relay after the set time.

Did my head in for a while but twas shit easy looking back at it now. 

[beanflying]

@tautech - like the hack 

I did too when I finally got my foggy brain around the logic of it all. 
Had to have a break and clear the brain before I could get it to work as I wanted. 
I had 2 lots of NO/NC contacts to work with, 1 set in each of the flow switch and the timer that when powered switched its relay after the set time.

Did my head in for a while but twas shit easy looking back at it now. 

Make a different cover for the Valve to parcel the two together and sell them back to the farmers of NZ Basic branded flow switches without a timer will run to nearly $100 each.

[VK5RC]

+1  re beanflying, plenty of semi / rural properties would be happy to buy a good product like that.

Some of that 'simple logic' can do your head in     

[tautech]

@tautech - like the hack 

I did too when I finally got my foggy brain around the logic of it all. 
Had to have a break and clear the brain before I could get it to work as I wanted. 
I had 2 lots of NO/NC contacts to work with, 1 set in each of the flow switch and the timer that when powered switched its relay after the set time.

Did my head in for a while but twas shit easy looking back at it now. 

Make a different cover for the Valve to parcel the two together and sell them back to the farmers of NZ Basic branded flow switches without a timer will run to nearly $100 each.

I'd thought of that however shoe horning this into my abomination of control circuitry was easy as it's all DIN rail 12V relays cascading to 230VAC and finally to a 415VAC 3ph contactor.
The timer bit of it would need its own 12V supply however that could be done with a walwart as it only drew ~50mA max.
You'd have to interface it into 230VAC to control the coil of mains contactors. Yes you could put together a control package but then to do the job properly and legally have it then certified as safe for sale. 

I looked at producing the bigger picture some years back with 6V PV panel powered remote tank level sense and RF control of the pump.....the pump house bit is all sorted now so I should get back onto the automated tank level sense however some little redesign is required now I'm venturing into Lipo batteries.

I was a few years too late as these guys released some cool products while I was working on mine:
https://www.smartwatertech.co.nz/product

Selling TE now seems simpler. 

Edit to add
This thread has a bit about what I'm doing:
https://www.eevblog.com/forum/rf-microwave/antenna-project-log/

[beanflying]

The ME Mack ones at around $300 AUD run everything under the hood but compared to the cheapy Chinese one are built like a tank and much larger in the body. Worth the $ if it just had to work or else.

One of the locals here has been building and selling 4G based Tank fill and monitoring systems but I think Lora based might be worth a go too but I have to many other things to play with ahead of it

[med6753]

@tautech - like the hack 

I did too when I finally got my foggy brain around the logic of it all. 
Had to have a break and clear the brain before I could get it to work as I wanted. 
I had 2 lots of NO/NC contacts to work with, 1 set in each of the flow switch and the timer that when powered switched its relay after the set time.

Did my head in for a while but twas shit easy looking back at it now. 

Make a different cover for the Valve to parcel the two together and sell them back to the farmers of NZ Basic branded flow switches without a timer will run to nearly $100 each.

I'd thought of that however shoe horning this into my abomination of control circuitry was easy as it's all DIN rail 12V relays cascading to 230VAC and finally to a 415VAC 3ph contactor.
The timer bit of it would need its own 12V supply however that could be done with a walwart as it only drew ~50mA max.
You'd have to interface it into 230VAC to control the coil of mains contactors. Yes you could put together a control package but then to do the job properly and legally have it then certified as safe for sale. 

I looked at producing the bigger picture some years back with 6V PV panel powered remote tank level sense and RF control of the pump.....the pump house bit is all sorted now so I should get back onto the automated tank level sense however some little redesign is required now I'm venturing into Lipo batteries.

I was a few years too late as these guys released some cool products while I was working on mine:
https://www.smartwatertech.co.nz/product

Selling TE now seems simpler. 

Edit to add
This thread has a bit about what I'm doing:
https://www.eevblog.com/forum/rf-microwave/antenna-project-log/

Glad you got this all sorted.  My day has gone to shit. Took my '04 Honda Civic in for annual inspection. Turns out the tires are dry rotted and cracked. Won't pass. I only drive that car a few thousand miles per year and the thread isn't even half worn. But they have a date code of 2013 and the rubber is drying out. Gonna take about $500 USD went all is said and done to bail it out of jail. 

Oh well. 

[bd139]

That's what happened to mine recently. Rear ones were cracked. I sympathise.

Edit: date code was 2014 on mine.

[Mr. Scram]

The solution is to do more burnouts.

[Specmaster]

@tautech - like the hack 

As if I don't have enough HH DMMs, a Brymen 869s jumped into my 'basket' after reading some of joesmith's HV pulse testing - not that I need HV pulse resistance mind you, but my ability to stuff up is legendary! 

Also have bought another rack 1.8m H x 1.5m W x 0.5m D  to put behind my desk unit to beef up the current shelving 

Good buy on that 869, I got the 867, which is basically the same meter. It should be one of your better buys I reckon, let me know your opinion once you get it have used it a few times.

[Kosmic]

Cheap HP 34401a on ebay (US)

https://www.ebay.com/itm/HP-34401A-6-Digit-Digital-Multimeter/303176372805?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

[med6753]

The RCA WO-505A cooked for several hours yesterday and noticed something that may need attention. The trace is not as bright as I feel it should be. And as you vary the intensity control both the horizontal and vertical gain vary with the control. Shouldn't do that. These symptoms usually point to one of two things: Low HV or a very tired CRT. Obviously could be both too. And outside chance it's a design issue but I'll give RCA benefit of the doubt.

So got out the HV probe. Per the manual the HV should be -1.3KV. I'm measuring -1152V which is within the +/- 20% usually spec'ed but I think it's too low. This is the HV circuit. A bunch of epoxy caps and 4 HV rectifiers. Those caps rarely go bad but I suspect one of more may be going leaky. So I have to decide if I'm going to completely rebuild that circuit, including new rectifiers, or just leave it.

[bd139]

Those caps will be leaky. Not only that they'll eventually bugger up the transformer if you don't replace them. Can recomment HVstuff.com's blue disc ceramics. Dirt cheap, do the job nicely!

The solution is to do more burnouts.

1.0L front wheel drive. Hmm 

[Specmaster]

Cheap HP 34401a on ebay

https://www.ebay.com/itm/HP-34401A-6-Digit-Digital-Multimeter/303176372805?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

I got all excited there for a minute, it might be cheap for you but sadly not so for us Brits, after paying the shipping cost which is almost double the asking price it comes £404.81 and then that doesn't cover any import duty that customs deem applicable  Looks like my Solartons were a real bargain after all then 

[med6753]

That's my concern too and the transformer will be unobtanium. Gonna price out and order the parts.

[Kosmic]

Cheap HP 34401a on ebay

https://www.ebay.com/itm/HP-34401A-6-Digit-Digital-Multimeter/303176372805?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

I got all excited there for a minute, it might be cheap for you but sadly not so for us Brits, after paying the shipping cost which is almost double the asking price it comes £404.81 and then that doesn't cover any import duty that customs deem applicable  Looks like my Solartons were a real bargain after all then 

Sorry I should have precise. This is mostly for North America.

[med6753]

That's my concern too and the transformer will be unobtanium. Gonna price out and order the parts.

It's a no brainer. Just priced out all the parts from Mouser and it's cheap. The only concern I had was the 1N3563 HV diodes. Finally found a spec sheet and they are 1KV, 750mA. 1N4007 will be a perfect sub as they are 1KV, 1A. 

[bd139]

Good news 

My kind of HT circuit actually. One that doesn’t require black magic

[mnementh]

https://www.asciipr0n.com/pr0n/pinups/pinup00.txt (nsfw) 

I still have some paper version of those, buried somewhere.

The best was a nightview of the iconic GPO (now BT) Tower in central London. To get adequate darkness there was several layers of overprinting. I'm mildly surprised the paper survived intact.

I chose Meriday because she is arguably the first "internet meme" to ever go "viral"; my first exposure to such filth  was a usenet portal on a dialup connection to Gorgar's Castle out of Rochester, NY. As you might imagine, that BBS served primarily D&D nerds playing long-distance campaigns. WoW can suck it, man. 

I was rocking near state-of-the-art with a 1MB 1024KB 286-XT, 15 inch (!!!) Trinitron-based 1024x768 EEGA (32-color row/column mapped display vs 12" 640x480 8-bit bitmap VGA which was just then becoming the standard) bare-chassis display bought out of the back of the Computer Shopper (I made an aluminum sheet cabinet for it in the high-school metal shop) with yup... an ST-225 (maybe I'd upgraded to an ST-238 by then) hard drive w/DOS 3.3 and later Win3.1 . 

OT
Something for Bean and mnem that we discussed a good while back.
Finally finished the dry run protection on that new pump installed back in Feb. 
$12 flow sense switch plus a $1 timer chopped/hacked/cleverly installed  into the 12V pump control circuitry so that the pump will only run for 2s without sensing water flow.
Bonus visual feedback in that the ON light atop the pump shed power pole indicates the NO flow by going OUT/OFF when the NO flow sense triggers.
That's put that chapter to bed until the next stuff up happens. 

I recall bean warning to make the cross-section of the vane on that switch small enough not to give too much leverage so the switch didn't get broken; how did you resolve that?

Myself, I'd print a box to go over that board. If dirt and rust can get in there where it's mounted (as seen in the photo), bugs and moisture can too.

mnem
"You are in a maze of twisty little passages, all alike..."

[Specmaster]

@Kosmic I'm not sure that it really is a cheap 34401A even for lucky fellows in North America time you've paid your shipping, given the state of it and the scant info by way of decent photos, it could still pose a significant risk of needing quite a bit of remedial work needing to done. When I think I only paid £133 for 2 x Solartron 7150 Plus meters, OK, they need the mains filter replacing which did add about £80 to the cost but even so they cost a lot less, but that said, I know I'm a cheapskate 

[Kosmic]

@Kosmic I'm not sure that it really is a cheap 34401A even for lucky fellows in North America time you've paid your shipping, given the state of it and the scant info by way of decent photos, it could still pose a significant risk of needing quite a bit of remedial work needing to done. When I think I only paid £133 for 2 x Solartron 7150 Plus meters, OK, they need the mains filter replacing which did add about £80 to the cost but even so they cost a lot less, but that said, I know I'm a cheapskate 

They sell at around 400 - 500$ here. So below 300$ is the lowest I seen for a while. Also the 34401a is a hell of a meter. Really like mine.