Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Why am I actually looking at a 2215A on CL for $120...? Am I outta my scaly widdle mind...? 

mnem
"There's enuf misery to go around without grabbing for more." ~mum

[AVGresponding]

[Kosmic]

Apparently they had to raise the price to make back for their losses on the $82 ones.

Same link but different seller. This one is from "Electro-Meters Co. Ltd.." and I bought from "Spreetail".

The product description is great.  Only good for 50mhz, oh well at the probes have three times the bandwidth. 

Brand:Riorand; the ds1054z series is the new economical digital oscilloscope to meet the customer's application demands with its innovative technology, industry leading specifications, powerful trigger functions and broad analysis capabilities. 50 mhz bandwidth with a 7-inch display and ultravision technology as well as a host of options. Add the optional analysis, decoding, deep memory, and integrated 2 channel waveform generator for a powerful 4 channel scope at an exceptional price. Standard probes: rp2200 150mhz bw passive probe:4 sets.

David

the 100MHz bandwidth is optional. So they ship all the hardware for 100MHz (including the probes) and try to encourage you later to unlock the feature.

Just unlocked mine. Work fine at 100MHz now. The 24M Memory was already unlocked. It's a nice little scope for 65$  Think I'm going to sell the 200MHz Owon I have here.

[YurkshireLad]

Damn, I should have bought one. Thought it was too good to be true.

[mnementh]

Apparently they had to raise the price to make back for their losses on the $82 ones.

Same link but different seller. This one is from "Electro-Meters Co. Ltd.." and I bought from "Spreetail".

The product description is great.  Only good for 50mhz, oh well at the probes have three times the bandwidth. 

Brand:Riorand; the ds1054z series is the new economical digital oscilloscope to meet the customer's application demands with its innovative technology, industry leading specifications, powerful trigger functions and broad analysis capabilities. 50 mhz bandwidth with a 7-inch display and ultravision technology as well as a host of options. Add the optional analysis, decoding, deep memory, and integrated 2 channel waveform generator for a powerful 4 channel scope at an exceptional price. Standard probes: rp2200 150mhz bw passive probe:4 sets.

David

the 100MHz bandwidth is optional. So they ship all the hardware for 100MHz (including the probes) and try to encourage you later to unlock the feature.

Just unlocked mine. Work fine at 100MHz now. The 24M Memory was already unlocked. It's a nice little scope for 65$  Think I'm going to sell the 200MHz Owon I have here.

Oh, that's right... just stomp on the dwagon's tail after you trip over and break it... 

mnem
*toddles off to move more stuph*

[Vince]

VOLTAGE REGULATORS

Sorry for the delay ! Been busy in the house doing other things.

Didn't you find any TO-3 ones with a "K" suffix? The LM323K is 5V 3A, for instance. The LM7812K is rated for 1.5A.

Oh not I am confused again... the datasheet I have for the "vanilla" L79XX , no suffix then, says it can do 1.5A.   So I though the standard/default current output for a 78/79 was 1.5A, then suffixes would make that vary up or down.

The LM7812K is rated for 1.5A.

LM7812K I just downloaded the, well, 'a' datasheet (attached below) and it says 1.0A not 1.5 ?! 
Confused even more now !
Oh dear... it's really a shit show these regulators... I think what I will do is simply consider they are all 1.0A so as to be on the safe side ! 

So you have neither LMx09 nor LMx40 regulators? And neither LMx17, x37, x50 nor LMx38?

Oh yes I have some of those ! 

- I have one LM340 5V TO220.

- LMx09 I have 3 big ass TO3 LM309K  5Volts ... but only 1.0A the datasheet says   
You realize how old these dinosaurs are when you see the datasheet on the first page says they are "compatible with DTL logic " !! 
Also have a couple ancient SFC2309, TO3 1Amp 5Volts.

- LMx40 I have a TO3 LM340K, but still limited to 1.0A    Looks like most of these TO3 variant didn't give you more current, only more power dissipation which back in the day was welcome because often they didn't care and just put 25 or  :palm:30Volts in to get 5V out !

- LMx38 I have one TO3 338K.  Looks like a beefy LM317... adjustable positive, 1.2V to 30+ volts..... 5A !!!    That's lab power supply in itself !   Just need to add a transformer, bridge rectifier, filter caps, and a pot and that's it 

- LM317/337 : only 1.5 this one, prefer the 338K !   .... but 317 is available in T0220 so more practical if you don't need the 5amps...
I have x3 317. One TO3 and two TO220.  But I have no 337/ negative adjustable.... plenty of fixed negative thought, so I could always "hack" those to get whatever voltage I need, I guess....

- x50 ? That does not ring a bell... what would be valid / full part number for example ? Fixed voltage ? Adjustable ?  Low current ? High current ?

And an LT1070 should also be at hand when needed! Vince, you really need to round out your collection!
Tsktsktsk

Doesn't sound familiar either... maybe these were not wide spread 30 year ago when I was a kid and garnered the rudiments of electronics I am now trying to grow...
Let me see what that is.... OK... a switching regulator, that's a whole different topic ! 
3V to 60V  at the input, boost converter... internal switching transistor can do 5Amps... doesn't need a lot of external components.... hmm yes sounds like a very flexible / versatile little device, might be good to have a few in stock indeed !
I don't have any or almost no switch mode regulators. Found half a dozen in my salvaged pile, but 5 of them were too "TV" specialized to be reused, realistically. so I kept only one that looked general purpose enough, a KA1H0165R.

I bought some old TL494 or something 5 years ago because I needed them to fix the SMPS that blew iun my Tek 2232 scope, ahem....
So yeah, I would say I have zero modern switching regulators.
Might find a few in the pile of scrap boards that I have yet to process. Many from modern(is consumer appliances, flat TV or what not. Maybe these have general purpose switching regulators I could reuse. We shall see....

OH !!! Just remembered something, I have more regulators hiding somewhere ! 30 years back the old man bought me some parts so I could build my own power supply... a nice extruded aluminium case, a couple 4 digit reflective LCD display and the ICL chips to drive them, pots, a nice big ass toroidal transformer... I kept all these parts together, inside the case, to make sure I don't lose them.  So I just dug out that box and sure enough all the parts are still in there 30 years later !   So let's see what I have got exactly there.... hmmmm..... FOUR TO3 LM317K !!!     ... and a TO3 LM323K that AVG mentioned, so I DO have one then in fact, yeah  !  OK let's add these to my inventory / spreadsheet...

Thanks for reminding me about the S series. There's at least one still missing from the list however - the L200!

Oh yeah that one does ring a bell ! 30years ago my dad invited me at his workplace so I could do some experiments with this regulator. He would make me do experiments with BJT's too, to learn the basics, before my class mates saw it at school. I was always ahead of them
Yes, the L200...
I think it didn't get used a much as the LM317 because its minimum output voltage quite high, 2.85V versus only 1.25V for the LM317...

At least, I've sent him two Tesla MAA723H. 

Tesla what ?!  I thought they made cars ?! 

No that wasn't me ! You sent me a bunch of 709 op-amps....

(running to the bench to check them)... OH !!!!!

The two cans that have a yellow dot instead of the red dot all the others have.... they are NOT 709  they are these Tesla 723 !!! 

Oh my bad ! You sent me even more stuff than I had realized !!: 

Google found me the datasheet for them but it's written in some funky language I just can't understand. Eastern European country maybe.... I don't know
I guess it's  a 723 voltage regulator then... with special specs ?
I think I might have some 723 in DIP package in the old stock the old man gave me. It was popular back then, it's the kind of IC he would probably have had in his stock... I don't know for sure though, as I have yet to sort all my IC's ! I have done the passive components, now discrete semiconductors almost done (still have to sort lots of beefy diodes). Then I will soon move on to sorting all the IC's...

[Kosmic]

Apparently they had to raise the price to make back for their losses on the $82 ones.

Same link but different seller. This one is from "Electro-Meters Co. Ltd.." and I bought from "Spreetail".

The product description is great.  Only good for 50mhz, oh well at the probes have three times the bandwidth. 

Brand:Riorand; the ds1054z series is the new economical digital oscilloscope to meet the customer's application demands with its innovative technology, industry leading specifications, powerful trigger functions and broad analysis capabilities. 50 mhz bandwidth with a 7-inch display and ultravision technology as well as a host of options. Add the optional analysis, decoding, deep memory, and integrated 2 channel waveform generator for a powerful 4 channel scope at an exceptional price. Standard probes: rp2200 150mhz bw passive probe:4 sets.

David

the 100MHz bandwidth is optional. So they ship all the hardware for 100MHz (including the probes) and try to encourage you later to unlock the feature.

Just unlocked mine. Work fine at 100MHz now. The 24M Memory was already unlocked. It's a nice little scope for 65$  Think I'm going to sell the 200MHz Owon I have here.

Oh, that's right... just stomp on the dwagon's tail after you trip over and break it... 

mnem
*toddles off to move more stuph*

I can sell you the Owon you missed 2 years ago 

[Kosmic]

Glad you managed to get it working... that now reminds me I have a 453 of my own taking up space under the bench.... bought 9 months ago... started work on it. Never saw a trace on the thing, no HV. As I was working on it I saw the magic smoke escape from the HV transformer.... which is not good a tall, me thought back then ! 
You all gave me good advice and info so maybe I will find the courage to unwind the transformer and see if I can fix the wire that blew. Hopefully I don't have to unwind the transformer 100% to find the scene of the accident... 

Came across this the other day actually which might be helpful





Thanks, BD - I think that will be VERY helpful and inspirational once I get the 547 back up on the bench, though that'll probably not happen until cooler weather returns - summer is more a play-with-solid-state-stuff time, especially with the current cost of angry pixies - cant see using them to run an air conditioner while six feet away simultaneously using still more of them to generate heat in old Tek iron - strikes me as rather counter productive.

-Pat

I also got a high voltage transfo to rewire and was planning to do that by hands 

Funny that nobody made a cheap CNC winding machine. I might look into that.

[bd139]

I also got a high voltage transfo to rewire and was planning to do that by hands 

Funny that nobody made a cheap CNC winding machine. I might look into that.

There are a number of 3d printed ones out there. Usual threaded rods, steppers, extrusion + 3d printed parts.

[AVGresponding]

-snip-

Main reason for using L200 is independent adjustable V/I regulation.

As for confusion re S, K, M, L I'd say test tha fucka... there may be some leeway with modern copy/fake parts, but you should be able to establish legit SOAR with legit parts.

[Cubdriver]

I also got a high voltage transfo to rewire and was planning to do that by hands 

Funny that nobody made a cheap CNC winding machine. I might look into that.

There are a number of 3d printed ones out there. Usual threaded rods, steppers, extrusion + 3d printed parts.

This one looks very interesting, but as of the last time I checked a while back he hadn't really posted any further details.


-Pat

[bd139]

I have checked the following list and he is not present so it might be worth asking him

https://en.wikipedia.org/wiki/List_of_inventors_killed_by_their_own_invention

[Vince]

-snip-

Main reason for musing L200 is independent adjustable V/I regulation.

As for confusion re S, K, M, L I'd say test tha fucka... there may be some leeway with modern copy/fake parts, but you should be able to establish legit SOAR with legit parts.

Oh yes stupid me ! Should have not skimmed the datashhet so fast, should have guessed those 2 extra pins were there for something ! 

Wow built-in current limiting is super cool, wanna buy one now ! 

[xrunner]

the 100MHz bandwidth is optional. So they ship all the hardware for 100MHz (including the probes) and try to encourage you later to unlock the feature.

Just unlocked mine. Work fine at 100MHz now. The 24M Memory was already unlocked. It's a nice little scope for 65$  Think I'm going to sell the 200MHz Owon I have here.

Last time I measured it like 3 - 4 years ago the unlocked "100 MHz" BW was actually ~ 130 MHz. Be interesting if you would check it too. 

[Kosmic]

the 100MHz bandwidth is optional. So they ship all the hardware for 100MHz (including the probes) and try to encourage you later to unlock the feature.

Just unlocked mine. Work fine at 100MHz now. The 24M Memory was already unlocked. It's a nice little scope for 65$  Think I'm going to sell the 200MHz Owon I have here.

Last time I measured it like 3 - 4 years ago the unlocked "100 MHz" BW was actually ~ 130 MHz. Be interesting if you would check it too. 

With a fast pulse I got 243MHz / 1.44ns rise time (to be taken with a grain of salt).
With a signal generator I get to the -3db point at 177MHz.

[xrunner]

the 100MHz bandwidth is optional. So they ship all the hardware for 100MHz (including the probes) and try to encourage you later to unlock the feature.

Just unlocked mine. Work fine at 100MHz now. The 24M Memory was already unlocked. It's a nice little scope for 65$  Think I'm going to sell the 200MHz Owon I have here.

Last time I measured it like 3 - 4 years ago the unlocked "100 MHz" BW was actually ~ 130 MHz. Be interesting if you would check it too. 

With a fast pulse I got 243MHz / 1.44ns rise time (to be taken with a grain of salt).
With a signal generator I get to the -3db point at 177MHz.

That deal is looking better and better! 

[Kosmic]

I also got a high voltage transfo to rewire and was planning to do that by hands 

Funny that nobody made a cheap CNC winding machine. I might look into that.

There are a number of 3d printed ones out there. Usual threaded rods, steppers, extrusion + 3d printed parts.

This one looks very interesting, but as of the last time I checked a while back he hadn't really posted any further details.


-Pat

I was thinking of something like that.

[Neomys Sapiens]

VOLTAGE REGULATORS

I don't have any low current ones, which I guess makes sense since I have only beefy TO220 and TO3 packages. Since these can put out 1 or 1.5Amp, why would any manufacturer artificially limit them to 500mA ?! So I guess the only 'L' 500mA ones are those supplied in small packages like TO92 or SOT23 surface mount something or other. I don't have these.

OK Murphy !

I have just finished sorting and organizing them all... just need to update my spreadsheet and print labels.... tomorrow. 2AM here I am going to bed.

So out of nearly 100 regulators.... guess what, yes I found ONE that proves me wrong... ONE TO220 package that's low current ! 

But it's not an 'L' , it's an 'M' !

A 78M12 ...so I pulled the datasheet and yeah, it's a 500mA version ! Why... why do these things even exist !   
Makes for a smaller pass transistor inside, makes the regulator half a cent cheaper maybe ? I guess for high volume commercial electronics it can count ?! 

So the 500mA version is an 'M'... so what is an 'L' ? I pulled the datasheet for that one as well. It's also a low current version indeed, but not 500mA, no.... the 'L' is only 100mA ! THESE are indeed the ones that come in the tiny packages, TO92 and surface mount.
Datasheet says these are intended mostly as an improved " Zener + resistor " replacement. I guess why not, makes sense...

Well thanks everyone for your participation, that was quite a refresher on these regulators. Think I now have my basics right...

 

Didn't you find any TO-3 ones with a "K" suffix? The LM323K is 5V 3A, for instance. The LM7812K is rated for 1.5A.

And 78Sxx in TO220 are rated 2A. So you have neither LMx09 nor LMx40 regulators? And neither LMx17, x37, x50 nor LMx38? And an LT1070 should also be at hand when needed! Vince, you really need to round out your collection!
Tsktsktsk

Thanks for reminding me about the S series. There's at least one still missing from the list however - the L200!

I was limiting the list intentionally at 3-terminal ones. Otherwise I would have not only included the L200, but also the LM104, LM106, LM2991, LR8K4, SG1501, SG1532, ....
LM150/250/350 is a 3A adjustable between the 117 and the 138.

[TERRA Operative]

This should be fun for a small diversion from the Tek Scopes...

[tautech]

the 100MHz bandwidth is optional. So they ship all the hardware for 100MHz (including the probes) and try to encourage you later to unlock the feature.

Just unlocked mine. Work fine at 100MHz now. The 24M Memory was already unlocked. It's a nice little scope for 65$  Think I'm going to sell the 200MHz Owon I have here.

Last time I measured it like 3 - 4 years ago the unlocked "100 MHz" BW was actually ~ 130 MHz. Be interesting if you would check it too. 

With a fast pulse I got 243MHz / 1.44ns rise time (to be taken with a grain of salt).
With a signal generator I get to the -3db point at 177MHz.

Hardly likely, recheck your work.....if it's for the 100 MHz Rigol.

[Brumby]

Congratulations!

But you have to wonder .... how come the price?

Best never to ask questions like that 

Kosmic doesn't have to ... he's come out a winner.


Me...?  Just curious.  Could be anything from "fallen off the back of a truck" to a surprise inclusion in a bulk acquisition ... or maybe a part of a "Storage Wars" episode?

I had another thought last night...
Fulfillment by Amazon with the seller making a typo in the price.   ???

[vk6zgo]

Today, I decided to do some "ham Technicianing"!

I scratched my bum, donned my bib & braces overalls, picked a few fleas out of my beard, & headed off to the "shack".
Once there, I let off a stentorian fart, (my dog sniffed the air, & quickly vacated the scene), settled down on the long suffering "operator's chair", moaned loudly, & set to work.

The"patient" is an elderly Yaesu FT707 transceiver.

This rather nice looking device has a strange fault, with both the "carrier" control which adjusts output power in the CW (morse) mode, & a similar one in the SSB mode associated with the "mic gain" control.
In both cases, the control seems to go from "zero" to "flat out", if the control is moved, which makes the controls, & hence, the radio useless.

My main fear was that both pots were faulty, & initial tests, looking back at them, seemed to bear this out, with the resistance between the moving contact & the chassis, measured with my Fluke 77, jumping around as the pots were turned.
This was worrying, because they are pretty much "unobtainium".

After digging deeper into the manual I downloaded, I found several pages with better representation of the circuitry involved, so I resolved to try again, today.
This more thorough check still showed the resistance reading "varying all over the place", but, knowing that the "77" was a bit ancient (& digital) , I decided to call upon an even older device-------my HP 410C!

On Ohms, the 410C showed the resistance varying smoothly on both pots, ----What the hell?
Trying the Fluke again, showed the previous situation.

Slowly, my ancient solder smoke addled brain found the answer ---"Dawk!" the Fluke was auto ranging, hence the weird readings!!
Pushing the range hold button changes the readings whilst turning the pots  to something similar to that of the 410C!

Definitely, a "Trap for Old Players"!

[capt bullshot]

VOLTAGE REGULATORS

...

Some thoughts:
with modern components, you won't find any numbering system worth remembering.

At a certain age of the components, just like the stuff you're dealing with right now, one could find quite an amount of generic numbers like 7805 and everyone knew it's a 1.5A 5V regulatur in TO220 case, as long as it itsn't. One often could easily identify manufacturers and their product lines by the prefix letters, while the postfix (or middle) letters or the first digit of the number identified special characteristics of a device.
A certain number of these jelly bean devices still exist, are produced and used today.

Most young engineers don't even know about the above, they tend to find a special purpose IC for every purpose, often recommended by the manufacturer or their representatives. Their main focus is to sell the newer parts, since they all are more expensive than ye olde jelly beans. Except you buy a gazillion of them, like automotive manufacturers.

So, today there simply exist way to many different devices to have any kind of intuitive numbering system.

For the same reason - you don't have any switching regulator - I can't recommend getting a switching regulator that would be a good choice to keep some in stock. The old ones are poor in todays metrics, or quite complicated to use or both - while the modern ones have way to many variants, each of them designed for a small scope of applications.
In contrary, keeping some generic 78xx and 79xx stock is useful, because they can easily used in lab prototypes or bodged repairs.

[BU508A]

I was limiting the list intentionally at 3-terminal ones. Otherwise I would have not only included the L200, but also the LM104, LM106, LM2991, LR8K4, SG1501, SG1532, ....
LM150/250/350 is a 3A adjustable between the 117 and the 138.

That's an interesting one!
I've attached the datasheet of it. Is there a similar one of the SG1501A from Linear Technology?

And for entertainment purposes, I've added an issue of Electronic Design from 1973. Please see page 46 for the SG1501A.
Spoiler: it contains also a lot of Tektronix stuff fun. 

Well, I tried but I then saw it has a size of more than 56MByte and the forum is limited to 5MByte only.
So, here is the link: http://bitsavers.trailing-edge.com/magazines/Electronic_Design/Electronic_Design_V21_N14_19730705.pdf

[BU508A]

This ad just went online (nawts):
R&S RTM1054 / 500MHz / 3x 500MHz probes from R&S
https://www.ebay-kleinanzeigen.de/s-anzeige/rohde-schwarz-rtm-1054-oszilloskop-oscilloscope-4ch-500mhz-5gsa/2124048985-168-2639