Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

@mnementh The closest one is the small knob TBH but as bd139 said it would need to be white as the closest colour to the original. It also turns out that the knob for the TDS220 (file bd139 found) is printable according to the 3dhubs.com and there is a print centre in Chelmsford and they can print it in white, @50 microns and have it ready in 2 days apparently for £4.25 a knob?

The materials I'd try are

• SLA photopolymer (white, shiny, hard with a little flex) http://dirtypcbs.com/store/print3d
  Thread 2mm pitch, 2" dsameter:
  
  
• nylon (white, matt, slightly flexible) https://www.shapeways.com/materials/versatile-plastic
  

The probe tip costs ~£1 in SLA and ~£4 in nylon. The large probe handle cost ~£12

They can only print in ABS (black only from 200 to 100 microns) or PLA (selection of colours 200 to 50 microns).

[Specmaster]

Yep what FTDI did was inexcusable. Screw 'em.

Well damn it. Did it again. Bought something I shouldn't have

Fluke 87V. New (seller says) or very lightly used (most likely) at most with full probe pack. Sticky thing still on the screen. Looks like 2017 manufacture based on the date code on the probe pack.

I don't even need it  ... pathological TEA.

Beware, you're on that slippery slope to the edge rabbit hole known as voltnuttery, nothing wrong with a Fluke 87V, but does it add anything to what you already have with the Keysight and Brymen other than a flash of yellow? Not that I should be saying anything with my collection of meters 

[tggzzz]

We got an Estes sidewinder and stuffed a C engine in it and launched it slightly too close to Stansted airport and got chased by airport police.

A work colleague was intercepted by military police, since someone driving past his car noticed him pointing a Blowpipe(?) shoulder-launched missile at passing aircraft.

It was actually a Blowpipe simulator, developed for the military so they let him off. I had a couple of goes (while indoor!) at knocking out cars on the neighbouring A45.

There was no excuse. I was 20 years old at the time and knew better 

Evidently not

[tggzzz]

Yep what FTDI did was inexcusable. Screw 'em.

Well damn it. Did it again. Bought something I shouldn't have

Fluke 87V. New (seller says) or very lightly used (most likely) at most with full probe pack. Sticky thing still on the screen. Looks like 2017 manufacture based on the date code on the probe pack.

I don't even need it  ... pathological TEA.

Beware, you're on that slippery slope to the edge rabbit hole known as voltnuttery, nothing wrong with a Fluke 87V, but does it add anything to what you already have with the Keysight and Brymen other than a flash of yellow? Not that I should be saying anything with my collection of meters 

Voltnuttery with a 3.75 digit handheld? Not even close. Hell, that's neither sufficient to use a saturated Weston standard cell as a thermometer, nor to have to worry about draughts!

Start with 7 digits, and work upwards.

[mnementh]

@mnementh The closest one is the small knob TBH but as bd139 said it would need to be white as the closest colour to the original. It also turns out that the knob for the TDS220 (file bd139 found) is printable according to the 3dhubs.com and there is a print centre in Chelmsford and they can print it in white, @50 microns and have it ready in 2 days apparently for £4.25 a knob?

50 microns is excellent. You should get better results than I did, especially if the GCode they generate from the STL and their printer has been tweaked by an experienced user, not a total noob like me. Good price too, as you're getting ~20-30 minutes of gcode & printer prep, and 30-50 minutes printer time.

Sorry, but what I have on hand is black, silver and purple. Like I said, it was more a matter of letting you see what could be done, and seeing if my fix for the platen moving works.    I'm sure it won't go to waste... and even if it does, it was like 10¢ worth of filament. 

You'll want to take a knob with you & match up the color in person; most every filament maker has the same shade of "Pure white" or "Titanium white"; however, the shades of off-white like you'll want vary greatly, and many are somewhat translucent.

Any variety of SLA will be much better finish, but will be somewhat  translucent. You can get that easily from Shapeways if you want to pay their prices.

The ones I printed to show you are VERY serviceable, and have a good feel under your hand. What you get from your 3DP center should be better. 

Cheers,

mnem
*Printer-friendly*

[Specmaster]

We got an Estes sidewinder and stuffed a C engine in it and launched it slightly too close to Stansted airport and got chased by airport police. There was no excuse. I was 20 years old at the time and knew better 

Was that in Belmer Road by any chance? If so then that would explain for the police crack down on spotters along the perimeter fence adjacent to the road there 
Mind you I doubt that they would remember that incident now, which was years ago now. But the police are very twitchy about people spotting along that particular stretch for some reason.

I had a good day at North Weald today, up close and personal with a Jet Provest, a couple of Knats, a Mustang and a Spitfire which I even got to help putting to bed in its hanger tonight 

[Specmaster]

Voltnuttery with a 3.75 digit handheld? Not even close. Hell, that's neither sufficient to use a saturated Weston standard cell as a thermometer, nor to have to worry about draughts!

Start with 7 digits, and work upwards.

Well I thought that the 87V was a 4.5 digit meter? while not quite a 7 digit granted but there are different grades of voltnuttery and if you have 7 digits or more that i'm  certainly jealous, not that as I've said before, I need that level of accuracy, just love loads of digits  I doubt that real voltnutters dived straight in at a minimum of 7 digits but gradually worked their way upwards as I'm doing, started with 3.5 and in the space of 18 months upto 5.5, who knows what I'll have another 18 months, a empty bank account I reckon

[Cerebus]

A work colleague was intercepted by military police, since someone driving past his car noticed him pointing a Blowpipe(?) shoulder-launched missile at passing aircraft.

It was actually a Blowpipe simulator, developed for the military so they let him off. I had a couple of goes (while indoor!) at knocking out cars on the neighbouring A45.

Reminds me of Peter^*. Prior to being at university with me, he was at a well known boy's public school. The kind that has a serious combined cadet force where they get play with the big boys (on the logic that those who don't go into banking or government end up in the military). After an exercise with the big boy's Army, Peter abstracted a spent LAW anti-tank missile firing tube. This ended up at university with him a few years later. We discovered that the firing mechanism had a .22 short blank that initiated the rocket. It was quite easy to re-arm this. Adding a closed end to the tube and filling it with shaving foam provided a weapon that could have a devastating effect on someone's dignity at up to 15-20 feet. The custard pie squad for that year's rag week was feared more than any other before or after it.

^*Name changed to protect the guilty

Ooo, found a picture:

[Specmaster]

@mnementh The closest one is the small knob TBH but as bd139 said it would need to be white as the closest colour to the original. It also turns out that the knob for the TDS220 (file bd139 found) is printable according to the 3dhubs.com and there is a print centre in Chelmsford and they can print it in white, @50 microns and have it ready in 2 days apparently for £4.25 a knob?

50 microns is excellent. You should get better results than I did, especially if the GCode they generate from the STL and their printer has been tweaked by an experienced user, not a total noob like me. Good price too, as you're getting ~20-30 minutes of gcode & printer prep, and 30-50 minutes printer time.

Sorry, but what I have on hand is black, silver and purple. Like I said, it was more a matter of letting you see what could be done, and seeing if my fix for the platen moving works.    I'm sure it won't go to waste... and even if it does, it was like 10¢ worth of filament. 

You'll want to take a knob with you & match up the color in person; most every filament maker has the same shade of "Pure white" or "Titanium white"; however, the shades of off-white like you'll want vary greatly, and many are somewhat translucent.

Any variety of SLA will be much better finish, but will be somewhat  translucent. You can get that easily from Shapeways if you want to pay their prices.

The ones I printed to show you are VERY serviceable, and have a good feel under your hand. What you get from your 3DP center should be better. 

Cheers,

mnem
*Printer-friendly*

I appreciate you doing that as well, in fact if it was for my own personal scope, I'd be happy with black knobs TBH but this is one that I'm going to be selling shortly. I'll take an original knob with me tomorrow to see if they have extra colours to their website says, never till I ask will I?

[mnementh]

Yeah, I thought of that... I was concerned that the exact setup with the same fixture inductance/capacitance would be hard to replicate on the other side of the pond. But if we both started with the same cheap breakout PCB, or if we designed something quick and did a run on OSH Park, you could count on being able to replicate those results yourself, and you could compare against your bench LCR meter.

My thought with the SOT23-6 PCB was to do a true 4-wire connection, possibly with the shield separating the pairs. Or would that just beg common-mode noise to fu** with our heads?

Alternately, we could design a simple 4-wire PCB that plugs straight into the slot on the DE-5000; FUCK the wires entirely!

I'm up for something you can just ram in the front of it. HP did it with their high end LCR meters. Less wires and less contacts means less problems.

[DISCLAIMER: DON'T DO THIS AT HOME KIDDOS!!! You will set fire to your mom's prize beegonias, blow up your bicycle and have to walk to school, and daddy will take your birthday away!!!]

As a kid, I liked to stuff A & B size model rocket motors inside plastic stuff I wanted to destroy. Once the main burn melts the back end of a cheap plastic truck or airplane into goo, the chute charge goes off and splatters it everywhere. 

[YOU HAVE BEEN WARNED!!!]

mnem
"A misspent youth is better by far than a wise and productive old age."

We got an Estes sidewinder and stuffed a C engine in it and launched it slightly too close to Stansted airport and got chased by airport police. There was no excuse. I was 20 years old at the time and knew better 

You think just the 4 wires, or shield as well on the back side?


That's a good motor for a shorty build; I liked the Sidewinder in a stretch build with 24mm motor holder for E-size. Needs about 50¢ or so in the nose to balance the big motor.

A work colleague was intercepted by military police, since someone driving past his car noticed him pointing a Blowpipe(?) shoulder-launched missile at passing aircraft.

It was actually a Blowpipe simulator, developed for the military so they let him off. I had a couple of goes (while indoor!) at knocking out cars on the neighbouring A45.

Reminds me of Peter^*. Prior to being at university with me, he was at a well known boy's public school. The kind that has a serious combined cadet force where they get play with the big boys (on the logic that those who don't go into banking or government end up in the military). After an exercise with the big boy's Army, Peter abstracted a spent LAW anti-tank missile firing tube. This ended up at university with him a few years later. We discovered that the firing mechanism had a .22 short blank that initiated the rocket. It was quite easy to re-arm this. Adding a closed end to the tube and filling it with shaving foam provided a weapon that could have a devastating effect on someone's dignity at up to 15-20 feet. The custard pie squad for that year's rag week was feared more than any other before or after it.

^*Name changed to protect the guilty

Spud cannons. Reddi-Whip. President masks at Junior Prom.

mnem
Nudge-nudge, Wink-wink, Say no more.   

[mnementh]

(SNIP)
The ones I printed to show you are VERY serviceable, and have a good feel under your hand. What you get from your 3DP center should be better. 

Cheers,

mnem
*Printer-friendly*

I appreciate you doing that as well, in fact if it was for my own personal scope, I'd be happy with black knobs TBH but this is one that I'm going to be selling shortly. I'll take an original knob with me tomorrow to see if they have extra colours to their website says, never till I ask will I?

Glad to be of help!

This IS a collective support group; we support each other in our collective madness! 

mnem
Oooh... wife brought home egg lolls...

[tggzzz]

I had a good day at North Weald today, up close and personal with a Jet Provest,

As close as this, from a road near Bristol Airport?
https://www.google.co.uk/maps/@51.3886076,-2.6970066,3a,17.7y,145.1h,91.77t/data=!3m6!1e1!3m4!1sd3plnMnipUrOsGxTMy_ehA!2e0!7i13312!8i6656

a couple of Knats, a Mustang and a Spitfire which I even got to help putting to bed in its hanger tonight 

Folland Gnats?

[tggzzz]

Voltnuttery with a 3.75 digit handheld? Not even close. Hell, that's neither sufficient to use a saturated Weston standard cell as a thermometer, nor to have to worry about draughts!

Start with 7 digits, and work upwards.

Well I thought that the 87V was a 4.5 digit meter? while not quite a 7 digit granted but there are different grades of voltnuttery and if you have 7 digits or more that i'm  certainly jealous, not that as I've said before, I need that level of accuracy, just love loads of digits  I doubt that real voltnutters dived straight in at a minimum of 7 digits but gradually worked their way upwards as I'm doing, started with 3.5 and in the space of 18 months upto 5.5, who knows what I'll have another 18 months, a empty bank account I reckon

<plantiff voice> I was only trying to help </plaintiff voice>
<sotto voce muttley voice> hee, hee, hee, hee, hee </sotto voce muttley voice>

All you have to do is wait, obsessively look at auctions, and be prepared to understand how to repair the damn things. Then they are <£100

[mnementh]

Ooooh myyyyyyy...

Just stumbled across this on fleaBay. Looking is still free. 

More resistance: https://www.ebay.com/itm/192457484893


mnem
Who's this Grant fellow?

[Specmaster]

I had a good day at North Weald today, up close and personal with a Jet Provest,

As close as this, from a road near Bristol Airport?
https://www.google.co.uk/maps/@51.3886076,-2.6970066,3a,17.7y,145.1h,91.77t/data=!3m6!1e1!3m4!1sd3plnMnipUrOsGxTMy_ehA!2e0!7i13312!8i6656

a couple of Knats, a Mustang and a Spitfire which I even got to help putting to bed in its hanger tonight 

Folland Gnats?

Yes on both counts, all the planes were living and breathing, air worthy and all flew today and I was actually able to walk around them and touch them and the Knats were infact Folland Gnats (can't spell either these days  ) and the Spitfire I actually pushed back in its hanger and had a cup of TEA with the owner and pilot Peter Teichman himself, who actually flew his final public display today at Duxford Battle of Britain airshow. Finally hanging up his public display wings after 20 years in the business, He will be flying for personal enjoyment from now but may display at the odd show if he wants to but currently has no plans to display again.

The Gnats display team on the other hand will be continuing and possibly growing in size soon.

Details of both the display companies I was with today can found here, the Spitfire for instance http://www.hangar11.co.uk/ and the Gnats here http://gnatdisplayteam.org/display-dates/

[mtdoc]

Just stumbled across this on fleaBay. Looking is still free. 

They're on sale. 5% off. A bargain. What are you waiting for?

the Knats were infact Folland Gnats (can't spell either these days  )

Brings back sad memories of losing in the final round of my 6th grade spelling bee on the word knaw gnaw.

[URI]

Voltnuttery with a 3.75 digit handheld? Not even close. Hell, that's neither sufficient to use a saturated Weston standard cell as a thermometer, nor to have to worry about draughts!

Start with 7 digits, and work upwards.

Well I thought that the 87V was a 4.5 digit meter? while not quite a 7 digit granted but there are different grades of voltnuttery and if you have 7 digits or more that i'm  certainly jealous, not that as I've said before, I need that level of accuracy, just love loads of digits  I doubt that real voltnutters dived straight in at a minimum of 7 digits but gradually worked their way upwards as I'm doing, started with 3.5 and in the space of 18 months upto 5.5, who knows what I'll have another 18 months, a empty bank account I reckon

Well, it might depend on why one is buying a 87V multimeter.   

It doesn't give you a high resolution because it has 3,5 digit in normal mode and 4,5 digits in high res mode.
What it does give you on that level is more accuracy than average handheld multimeters and therefore a higher level of confidence in what it displays.

If that is what one is buying it for, than it's likely that there's voltnuttery ahead..   

In my part -started right away with 6,5 digit benchtop multimeters made by Philips (PM2534/PM3535). Having realised that they had the resolution but not the accuracy I wanted I went further down that rabbit hole ending up with three HP 3456A. Bought a 87V as a side effect in that time..   

There are some LTZ1000 I bought over ebay from a guy in the USA that are still waiting to be checked and verified. And -if checked ok might pimp one of my 3456A.

Bid for a Prema 8017 7,5 digit bench multimeter yesterday but was outbid saved from going further down that rabbit hole.   

[bitseeker]

Alternately, we could design a simple 4-wire PCB that plugs straight into the slot on the DE-5000; FUCK the wires entirely!

I'm up for something you can just ram in the front of it. HP did it with their high end LCR meters. Less wires and less contacts means less problems.

You think just the 4 wires, or shield as well on the back side?

I like that PCB fixture that plugs directly into the DE-5000 slots. I'm not sure if you need the shield. Any reason not to have it?

Ooooh myyyyyyy...

Just stumbled across this on fleaBay. Looking is still free. 

Free for a limited time...

[tggzzz]

Ooooh myyyyyyy...

Just stumbled across this on fleaBay. Looking is still free. 

More resistance: https://www.ebay.com/itm/192457484893

Since I'm in the mood to annoy people, this lot cost ~£70



Curiously the 100ohms doesn't seem to be 100 ohms
The Dekastat is 0-121.1 ohms (+20mohm), and you will notice the dials go all the way up to X and 11

All good things come to those that wait, and go to obscure hamfests and auctions The latter are really good for voltnuts 7 & 8 digit DVMs for £70, plus repair time

[bd139]

Alternately, we could design a simple 4-wire PCB that plugs straight into the slot on the DE-5000; FUCK the wires entirely!

I'm up for something you can just ram in the front of it. HP did it with their high end LCR meters. Less wires and less contacts means less problems.

You think just the 4 wires, or shield as well on the back side?

I like that PCB fixture that plugs directly into the DE-5000 slots. I'm not sure if you need the shield. Any reason not to have it?

If you're measuring sub-20pF or sub-20uH or so values then stray inductance and capacitance is a major issue so you would need it then for sure. I'm not too sure about the implementation of the DE-5000 though; it purports to be a 4-wire measurement tool but the lead head is only 3 wire. There are two functions of 4-wire measurements here: elimination of common mode noise and acting as a guard against stray capacitance. Not sure how you can do both of those with 3 wire termination. I haven't looked deeply into it yet and not sure I can afford a proper 4-wire E4980A

[Cerebus]

Brings back sad memories of losing in the final round of my 6th grade spelling bee on the word knaw gnaw.

Ah yes, the spelling bee, a peculiarly American way of torturing schoolkids. The British school equivalent is assuming that cross country running is a winter activity.

[bd139]

I loved cross country running in the winter! The enforced shower afterwards though; fuck that.

[tggzzz]

I loved cross country running in the winter! The enforced shower afterwards though; fuck that.

Running only occurred when there was an ankle deep puddle formed from melting slush. (Or where teachers might be lurking)

[Mr. Scram]

What do you guys reckon you can expect when people use the word "mint" to describe the condition of a device? What does it denote in your book?

[bd139]

For me, the appearance of being unused. Doesn't matter if it is used but there must be no evidence of it being used.