Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Nice score; finding one with the caps still on the knobs. 

Gonna find a replacement NE2 indicator, or epoxy the original back together...? I've done both.

mnem
 

Say, did you just break time here? Or is this NOT a comment on the post AFTER yours?

No, I posted right after David... then he tried to fix a fuxxored post, and wound up re-posting after me. By the time I realized it, others had replied to my post and his; so I decided to err on the side of discretion, and just backed slowly away from the KB...

mnem
Tonight when I chase the dragon
The water will change to Cherry Wine;
and silver will turn to gold.
Time out of mind...

[Neomys Sapiens]

A little searching found a good used plastic film based replacement capacitor that fitted the hole spacing, the power lamp also got replaced with the only spare I have (the original had disintegrated), need to find some more just in case. And I re-terminated the mains lead as someone had soldered the wire ends.

I've seen exactly the same mechanical failure on two similar era HP supplies. I think this can be raised to the level of "stock fault" for that generation.

I have some incandescent indicator bi-pin lamps which look the same from the front. You could wire them into the secondary and even gain with regard to scope of indication. They have a metal body and a opaque cap of the same form and they are from the US, but I can't give you the type right now.

[EEVblog]

I think, I forward this request to a more approbiate place   

Dave is asking for some TEA support:

If anyone knows of any decent test gear that isn't being marketing or distributed well, let me know though. I do want to expand the product portfolio.

Especially if you are having some ideas about a decent LCR-meter.       

Edit:

I'd like one, but it's hard find something good without an already well established distribution chain and low prices.
Brymen works because they have pretty horrible marketing and distribution in a lot fo the world, and the margins are good, so they are winners for me.
If anyone knows of a suitable one on the market please let me know, I do want to expand my product portfolio.

[Taki]

I just learnt about this TEA group therapy thread via Dave's tweet and after browsing a bit, I lost any qualms I had with my plans to buy a 4 channel DSO I definitely do not need. 

[Cerebus]

Nice score; finding one with the caps still on the knobs. 

Gonna find a replacement NE2 indicator, or epoxy the original back together...? I've done both.

mnem
 

Say, did you just break time here? Or is this NOT a comment on the post AFTER yours?

I have had a suspicion that I've seen that happen a couple of times recently. I can't be certain or point to some specific examples.

Gnif said that he's had some problems with GlusterFS* and it's not beyond possibility that includes write order issues between replicas - it depends how SMF uses the underlying filesystem. Somehow I don't see SMF as the kind of software that someone's programmed reliable multiphase commit protocols into. 

* A distributed, replicating virtual filesystem.

[Cerebus]

"The test equipment dark web"? Na. A bit sinistral, a bit sinister? Perhaps, but not "dark". None of us are trendy enough to have a dark mode. Given the average age in here it's a little surprising that most of us aren't accessing the web using Lynx and an ASR33 or a DecWriter.

Sorry, got to go, my difference engine is overheating. Needs a bit more tallow on the bearings.

[Cerebus]

I just learnt about this TEA group therapy thread via Dave's tweet and after browsing a bit, I lost any qualms I had with my plans to buy a 4 channel DSO I definitely do not need. 

That's what we like to hear here. Qualms be damned!

[Kosmic]

I think, I forward this request to a more approbiate place   

Dave is asking for some TEA support:

If anyone knows of any decent test gear that isn't being marketing or distributed well, let me know though. I do want to expand the product portfolio.

Especially if you are having some ideas about a decent LCR-meter.       

Edit:

I'd like one, but it's hard find something good without an already well established distribution chain and low prices.
Brymen works because they have pretty horrible marketing and distribution in a lot fo the world, and the margins are good, so they are winners for me.
If anyone knows of a suitable one on the market please let me know, I do want to expand my product portfolio.

You should check out the Mastech MS8911 (Tweezer LCR meter). They are really cheap (48$), work great, and are really hard to find (distribution problem ?). Also, Mastech is known to do OEM, so you might be able to cut a deal with them.

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3149418/#msg3149418



Edit: If anybody is looking for one, let me know. I ordered 2 by accident so I have one extra.

[tautech]

Hang in there the twiterer in Chief is about out 

   

Priceless from the Bean !

[tautech]

You should check out the Mastech MS8911 (Tweezer LCR meter).

If Dave is to do a bulk buy and get us substantial savings why not get something really good:
https://www.lcrresearch.com/
https://www.smarttweezers.com/

[EEVblog]

You should check out the Mastech MS8911 (Tweezer LCR meter). They are really cheap (48$), work great, and are really hard to find (distribution problem ?). Also, Mastech is known to do OEM, so you might be able to cut a deal with them.

Looks like the Global Specialties LCR-58 one I got

[tautech]

Looks like the Global Specialties LCR-58 one I got

Totally different critter.

[Kosmic]

You should check out the Mastech MS8911 (Tweezer LCR meter). They are really cheap (48$), work great, and are really hard to find (distribution problem ?). Also, Mastech is known to do OEM, so you might be able to cut a deal with them.

Looks like the Global Specialties LCR-58 one I got

Yeah, it's probably why it's impossible to find the Mastech one over here. We can get the Global Specialties easily from digikey though.

[Kosmic]

Looks like the Global Specialties LCR-58 one I got

Totally different critter.

No, other than the diode mode on the LCR-58 they are identical. Also Global Specialties don't create anything, they only do business with OEMs so the product is coming from another company. Probably Mastech.

[BU508A]

Looks like the Global Specialties LCR-58 one I got

Totally different critter.

The LC-display is looking differently.

[beanflying]

You should check out the Mastech MS8911 (Tweezer LCR meter). They are really cheap (48$), work great, and are really hard to find (distribution problem ?). Also, Mastech is known to do OEM, so you might be able to cut a deal with them.

Looks like the Global Specialties LCR-58 one I got

Dave, if you are interested in loaning both a set of LCR Research and Smart Tweezers for a few weeks play drop me a PM or Email. I am short on time to use them at present so I can do without and can drop them in a Postpak. Use them for a comparison/review or look at them to add to your store.

[Neomys Sapiens]

But doesn't that apply to rising the voltage only? Lowering is accomplished by Q1/Q3, which can certainly pull more than a few milliamps. This seems to me to be the important direction: In case of a sudden short at the output, get those MOSFETs shut off quick!

Yup, it's rising slew rate only. It's not wrong, it just instinctively feels like "not a lot of gate drive current". As I said, as long as there's enough practical transconductance there (which I can't be bothered to work out all the necessary conditions for) you've got a decent slew rate on the output. Your falling slew rate is going to be determined entirely by your load characteristics, because even if you can turn off the current through your pass transistors instantly you've no active down-regulation.

Actually, the drivers do pull down the output, albeit through the zener and 1.2 k resistor. If the output gets shorted, I don't really care about regulating the voltage down - my major concern then is to protect the pass transistors.
And this can also be said about most other lab supplies.

BTW, another possible cause for my "mishaps" occurred to me: the dangers of open source. What if the H6N100 wasn't overpowered but the source resistor failed open due to overcurrent? V_GDR may be 1000 volts, but with R=∞ it might approach V_GS, a mere 20 volts. That would explain gate-drain breakdown and subsequent bursting of the gate resistor!

Searching for a specific post on this forum is not exactly fun.

It was HERE where we discussed the paralell connection of MosFETs in linear mode, and their selection for closely matching transconductance:
https://www.eevblog.com/forum/projects/0-70v-0-5a-lab-power-supply-design/msg3007276/#msg3007276

[Kosmic]

You should check out the Mastech MS8911 (Tweezer LCR meter).

If Dave is to do a bulk buy and get us substantial savings why not get something really good:
https://www.lcrresearch.com/
https://www.smarttweezers.com/

From my point of view those are just overpriced. The bang for the buck is hard to beat on the Mastech one.

[tautech]

You should check out the Mastech MS8911 (Tweezer LCR meter).

If Dave is to do a bulk buy and get us substantial savings why not get something really good:
https://www.lcrresearch.com/
https://www.smarttweezers.com/

From my point of view those are just overpriced. The bang for the buck is hard to beat on the Mastech one.

As an owner of ST3 for some 15 years I would buy again in a flash as with any good tool the pain of the initial cost is long forgotten after years of trouble free service. Some years ago curiosity had me also buy a Mastech....probably an earlier version to the one you linked and it was a POS compared to a decent tool and I promptly gave it away.
YMMV

[beanflying]

You should check out the Mastech MS8911 (Tweezer LCR meter).

If Dave is to do a bulk buy and get us substantial savings why not get something really good:
https://www.lcrresearch.com/
https://www.smarttweezers.com/

From my point of view those are just overpriced. The bang for the buck is hard to beat on the Mastech one.

This is like comparing Uni-T against a quality bench meter. Both might do some of the same things but they are nothing really alike. If you want to 'sell' quantity then cheap and cheerful and 'some' of the same functionality has a place but if you want to pitch to a higher price point obviously you will sell less.

[BU508A]

Searching for a specific post on this forum is not exactly fun.

If I'm searching something in the EEVBlog forum, I'm using google with this parameter at the end of the search string:

Code: [Select]

site:eevblog.com/forum/

Example:

Code: [Select]

parallel MOSFET "linear mode" site:eevblog.com/forum/


[Kosmic]

You should check out the Mastech MS8911 (Tweezer LCR meter).

If Dave is to do a bulk buy and get us substantial savings why not get something really good:
https://www.lcrresearch.com/
https://www.smarttweezers.com/

From my point of view those are just overpriced. The bang for the buck is hard to beat on the Mastech one.

As an owner of ST3 for some 15 years I would buy again in a flash as with any good tool the pain of the initial cost is long forgotten after years of trouble free service. Some years ago curiosity had me also buy a Mastech....probably an earlier version to the one you linked and it was a POS compared to a decent tool and I promptly gave it away.
YMMV

I'm talking specifically about the MS8911 here. I would guess that buying Mastech product is more miss than hit 

[beanflying]

Searching for a specific post on this forum is not exactly fun.

If I'm searching something in the EEVBlog forum, I'm using google with this parameter at the end of the search string:

Code: [Select]

site:eevblog.com/forum/

Example:

Code: [Select]

parallel MOSFET "linear mode" site:eevblog.com/forum/


It is actually built into the forum in the form of a Mod I suggested Dave add some time ago. Use the top right search box and pulldown and select Google 

That said sometimes Google does fail in particular searching the TEA thread and it's 3k pages 

[med6753]

I just learnt about this TEA group therapy thread via Dave's tweet and after browsing a bit, I lost any qualms I had with my plans to buy a 4 channel DSO I definitely do not need. 

That's what we like to hear here. Qualms be damned!

Hell, buy 2 of them. 

[Kosmic]

You should check out the Mastech MS8911 (Tweezer LCR meter).

If Dave is to do a bulk buy and get us substantial savings why not get something really good:
https://www.lcrresearch.com/
https://www.smarttweezers.com/

From my point of view those are just overpriced. The bang for the buck is hard to beat on the Mastech one.

This is like comparing Uni-T against a quality bench meter. Both might do some of the same things but they are nothing really alike. If you want to 'sell' quantity then cheap and cheerful and 'some' of the same functionality has a place but if you want to pitch to a higher price point obviously you will sell less.

I don't know, Lcr research and smart tweezers are definitely not Keysight. On the other hand, I never owned any of their products, so I can't comment on the quality side of things.

It's really hard to generalize like that. Even Uni-T have some good product (1 or 2 at least  ).