Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

Anybody in need of some Tesla MAA723 = µA723?

2x 50 pieces of them are available here (NAWTS):

https://www.ebay.com/itm/133871141980

https://www.ebay.com/itm/133871142254

Ooof, proper bargain in prospect there. I'd have one of the lots myself if it doesn't go past €20+ shipping...

I'm pretty sure, they will exceed the 20 EUR mark significantly.

On the topic of vintage IC's and their clones, I'm currently looking for MN3007 bucket brigade delay lines, as I'm pondering a quality time  project with middle boy, The Chorus Pedal. (a chorus is, just to recapitulate, a guitar stomp box in which an analog delay line has its time LFO modulated creating a fatter sound)

So far, I've concluded that Philips invented the thing (back when Philips actually did things), Panasonic licensed them, and made the MN30xx series of delay lines.

Then, Roland bought the ICs, and made the chorus circuit in the Jazz Chorus amplifier, Dimension D chorus, CE-2 and Dimension C stomp boxes, et al.

Around 1999 Panasonic stopped making the MN30xx. Now, the clones attack. So far, I've found several brands,  Behringer with their IC brand Coolaudio, Visual Sound and Shangai Beilling Co LTD. Of course, since this is a sought-after chip, the market is full of "NOS" Panasonic-looking clones. From China. Yeah, right. That'll be authentic.

Anyway, if one accepts that it's going to be a clone build, it seems that one could get a quite nice couple evenings out of it, also doing things like drilling round holes at the right spot in Hammond boxes, et c.  BOM is en route to be a shopping list, and I'm looking at my component stash for what I've got already.

[bd139]

Ok crap arrived from Amazon. Automatic centre punch arrived broken so that's going back. Cheap Katsu work holder was a winner at £13. Wrapped some card around the Hammond box I was working on and lumped through it with the drill in a couple of seconds. Good tools FTW. The step cutter is wonderful as well. 30 min job took about 2 minutes with this thing. Holes are pretty good.

While I was waiting for those bits to turn up I fixed the NanoVNA resistors from the earlier RS delivery of stuff and recalibrated it and all good. I'm surprised it survived that!

So the Hammond box got a simple 6dB hybrid / return loss bridge chucked inside it so I have something somewhat easier to repair than the NanoVNA when working on active circuits. I didn't take any photos as it's three resistors and a toroid. Nothing special.

I decided to test it with the NanoVNA and got a surprisingly good directivity up to nearly 200MHz of better than 39dB. Was expecting it to die around 80MHz TBH.

So quick test against an input matching network on an amplifier I have lying around giving a fairly flat 27dB return loss which is better than 1.10 VSWR. Winner.



(and yes I know the NanoVNA does the above measurement on CH0 - I'm comparing the bridge to the NanoVNA here )

[mansaxel]

Just found this curious little thing here :

https://www.leboncoin.fr/equipements_industriels/2008120762.htm

An old HP little gizmo, unusual to me, in like new condition for a reasonable sum (50 Euros)... in case the HP nuts on here might be interested I can help...



An HP 403A , an " AC Transistor Voltmeter ".

I have no idea in concrete terms how you would use this thing and why you would want to use it... maybe you can teach me...

Only problem is the left side of the case has been mutilated in order to fit half a dozen connectors, but if the item is rare (?), might still be worth it as it should be easy enough to repair. I mean I assume the enclosure is made of metal so should be easy to plug the hole and respray the thing, no ?

Anyway, it caught my attention, a pristine old HP thingy for only 50 Euros over here is unheard of ! 

It's a transistor successor to instruments like the 400H. I have the predecessor, so am not interested. They pretty soon were surpassed by DMM's which of course can do all the things a full VTVM will do plus current, albeit with limited frequency response. For the thing they excel at, level matching in telecom and pro audio up to a MHz or so, there soon came specialised gear from several vendors, like Wandel & Goltermann, Siemens and I believe -hp- built something too, in Scotland, at that.

[Neper]

Just found this curious little thing here :

https://www.leboncoin.fr/equipements_industriels/2008120762.htm

An old HP little gizmo, unusual to me, in like new condition for a reasonable sum (50 Euros)... in case the HP nuts on here might be interested I can help...



An HP 403A , an " AC Transistor Voltmeter ".

I have no idea in concrete terms how you would use this thing and why you would want to use it... maybe you can teach me...

Well, it's a AC voltmeter with ranges from 1 mV to 300 V and calibrated in volts and dBm (0 dBm = 1 mW into 600 ohms = 0,775 Vrms). It has a switchable highpass filter and that about sums it up. Usage: well, quite obviously measing AC voltages at frequencies from  1 Hz to 1 MHz, e.g. while setting up a tape recorder or other audio equipment.

Here's some more info about it:

https://www.hpmemoryproject.org/wb_pages/wall_b_page_14a.htm

Ralf

[Cerebus]

So, have we finally broken the forum (it's moving like the whole server has been filled with treacle), or did everybody just coincidentally decide to take the evening off?

[Vince]

OK I think I understand now !

I was intrigued because it said : TRANSISTOR voltmeter... so well I assumed it was some piece of test equipment dedicted to carrying god knows what particular test on TRANSISTORS !

But... given how much you insist on how it's just a bloody voltmeter, general purpose... I now realize all they meant by "TRANSISTOR" ... is simply that it made USE of transistors in it ! Probably to differentiate it from its TUBE based counterpart....

Sorry, I just was not used to major TE brands bragging on the front panel about the fact their gear used transistors... I am used to that on consumer electronics where they feel the need to write all sorts of technical sounding jargon to impress the customers but... on a professional piece of TE no, think it's the first I see that ! 

It's like Tektronix was calling say their old 547 scope : " 50% TRANSISTOR 547 ", as the full name for it, instead of just "Type 547 ".....

OK so this piece of HP TE is nothing special then....

[Vince]

So, have we finally broken the forum (it's moving like the whole server has been filled with treacle), or did everybody just coincidentally decide to take the evening off?

Think we broke it... because it's super slow right now (again...), what a pain...
That, plus as Med experienced on his side of the world... I too have not received any e-mail notification from this forum today ! So it's definitely broken...

[tautech]

So, have we finally broken the forum (it's moving like the whole server has been filled with treacle), or did everybody just coincidentally decide to take the evening off?

Think we broke it... because it's super slow right now (again...), what a pain...
That, plus as Med experienced on his side of the world... I too have not received any e-mail notification from this forum today ! So it's definitely broken...

First thing I disabled as get quite enough rubbish in my inbox without any more. 
Forum working fine in NZ despite another plague of DOS attacks here. 

Edit
Posting threw a SMF dummy but recovered with a refresh.

[xrunner]

Think we broke it... because it's super slow right now (again...), what a pain...
That, plus as Med experienced on his side of the world... I too have not received any e-mail notification from this forum today ! So it's definitely broken...

It's teetering under the load, hardly able to keep up now. Checking if I have Discord ready to go on the laptop ... check. Plenty of beer for two days of forum outage - check.

Standing by for total FAIL. 

[tautech]

In other news.......we got nominated !   
https://www.apac-insider.com/awards/business-awards/

Not sure if to accept. 

[Cerebus]

In other news.......we got nominated !   
https://www.apac-insider.com/awards/business-awards/

Not sure if to accept. 

Hmm, looks like one of those types of awards. "... there are no compulsory costs in accepting a nomination or winning an award with APAC Insider. We do offer a variety of paid additional benefits for our winners,..."

Also: "Awards Coordinator - Katherine graduated from the University of Wolverhampton* with a degree in English Literature and Creative & Professional Writing." Which means at some point you'd have to listen to someone with a Wolverhampton accent, and that's a cruel thing to do to a person. it's not that people from Wolverhampton are like whining, self-pitying wretches, they just sound like it. At least they don't come from the nearby and similarly spoken Coventry, the town that gives 'accent' a bad name.

*Formerly Wolverhampton Polytechnic, formerly the Wolverhampton Tradesmen's and Mechanics' Institute. I'm not saying that the University toilets definately contain degree certificate dispensers on the walls of the cubicles, but I bet some student has annotated them to that end.

[tautech]

In other news.......we got nominated !   
https://www.apac-insider.com/awards/business-awards/

Not sure if to accept. 

Hmm, looks like one of those types of awards. "... there are no compulsory costs in accepting a nomination or winning an award with APAC Insider. We do offer a variety of paid additional benefits for our winners,..."

Also: "Awards Coordinator - Katherine graduated from the University of Wolverhampton* with a degree in English Literature and Creative & Professional Writing." Which means at some point you'd have to listen to someone with a Wolverhampton accent, and that's a cruel thing to do to a person. it's not that people from Wolverhampton are like whining, self-pitying wretches, they just sound like it. At least they don't come from the nearby and similarly spoken Coventry, the town that gives 'accent' a bad name.

*Formerly Wolverhampton Polytechnic, formerly the Wolverhampton Tradesmen's and Mechanics' Institute. I'm not saying that the University toilets definately contain degree certificate dispensers on the walls of the cubicles, but I bet some student has annotated them to that end.

Yeah for sure you don't get something for nothing and to get your name in the spotlight is where the $ additional benefits come calling for your hard earned dosh.
Compare the flashy booklet winners list to the winners listing:
https://www.apac-insider.com/issues/business-awards-2020/
https://www.apac-insider.com/winners-list/?award=16535-2020
 

Still, it's nice that someone thought well enough of us to forward a nomination but probably will keep our head down on this one....tall poppy's and all that.

[mnementh]

So, have we finally broken the forum (it's moving like the whole server has been filled with treacle), or did everybody just coincidentally decide to take the evening off?

I missed the whole thing; succumbed to exhaustion from battling a raging migraine all day. I crawled off to die as soon as the wife got home; just now having my dinner at 21:00.

mnem
"Honey, where are my paaants...?"

[mnementh]

In other news.......we got nominated !   
https://www.apac-insider.com/awards/business-awards/

Not sure if to accept. 

Hmm, looks like one of those types of awards. "... there are no compulsory costs in accepting a nomination or winning an award with APAC Insider. We do offer a variety of paid additional benefits for our winners,..."

Also: "Awards Coordinator - Katherine graduated from the University of Wolverhampton* with a degree in English Literature and Creative & Professional Writing." Which means at some point you'd have to listen to someone with a Wolverhampton accent, and that's a cruel thing to do to a person. it's not that people from Wolverhampton are like whining, self-pitying wretches, they just sound like it. At least they don't come from the nearby and similarly spoken Coventry, the town that gives 'accent' a bad name.

*Formerly Wolverhampton Polytechnic, formerly the Wolverhampton Tradesmen's and Mechanics' Institute. I'm not saying that the University toilets definately contain degree certificate dispensers on the walls of the cubicles, but I bet some student has annotated them to that end.

Hey, at least it isn't New Jersey.

mnem

[mnementh]

OK I think I understand now !

I was intrigued because it said : TRANSISTOR voltmeter... so well I assumed it was some piece of test equipment dedicted to carrying god knows what particular test on TRANSISTORS !

But... given how much you insist on how it's just a bloody voltmeter, general purpose... I now realize all they meant by "TRANSISTOR" ... is simply that it made USE of transistors in it ! Probably to differentiate it from its TUBE based counterpart....

Sorry, I just was not used to major TE brands bragging on the front panel about the fact their gear used transistors... I am used to that on consumer electronics where they feel the need to write all sorts of technical sounding jargon to impress the customers but... on a professional piece of TE no, think it's the first I see that ! 

It's like Tektronix was calling say their old 547 scope : " 50% TRANSISTOR 547 ", as the full name for it, instead of just "Type 547 ".....

OK so this piece of HP TE is nothing special then...

   

It is a wee bit more complicated than that, but yes. Just as other manufacturers have used the term "Dual FET" to identify a meter whose design uses a MOSFET differential amplifier circuit which functions similarly to that of a VTVM with its high sensitivity and high input impedance. In this case it serves also to warn the user about different usage considerations, like it being portable and highly sensitive, but due to having a transistor amplifier inside, it will be sensitive to ESD or other HV sources which a passive multimeter or VTVM would normally survive.

mnem
 

[mnementh]

...Still, it's nice that someone thought well enough of us to forward a nomination but probably will keep our head down on this one....tall poppy's and all that.

Congrats on getting noticed; we all do appreciate the proactive attitude you personally have taken with regards to acting as intermediary between your customers and would-be customers and your manufacturing partners.

That said... you've been noticed. That means you are on somebody's RADAR...

Good luck!

mnem
...and now they are going to be coming out of the woodwork...

[Vince]

OK I think I understand now !

I was intrigued because it said : TRANSISTOR voltmeter... so well I assumed it was some piece of test equipment dedicted to carrying god knows what particular test on TRANSISTORS !

But... given how much you insist on how it's just a bloody voltmeter, general purpose... I now realize all they meant by "TRANSISTOR" ... is simply that it made USE of transistors in it ! Probably to differentiate it from its TUBE based counterpart....

Sorry, I just was not used to major TE brands bragging on the front panel about the fact their gear used transistors... I am used to that on consumer electronics where they feel the need to write all sorts of technical sounding jargon to impress the customers but... on a professional piece of TE no, think it's the first I see that ! 

It's like Tektronix was calling say their old 547 scope : " 50% TRANSISTOR 547 ", as the full name for it, instead of just "Type 547 ".....

OK so this piece of HP TE is nothing special then...

   

It is a wee bit more complicated than that, but yes. Just as other manufacturers have used the term "Dual FET" to identify a meter whose design uses a MOSFET differential amplifier circuit which functions similarly to that of a VTVM with its high sensitivity and high input impedance. In this case it serves also to warn the user about different usage considerations, like it being portable and highly sensitive, but due to having a transistor amplifier inside, it will be sensitive to ESD or other HV sources which a passive multimeter or VTVM would normally survive.

mnem
 

Dwagon I think you are way too kind... it's just bragging / marketing !! 

Let's see what others might have to say about this...

[Neomys Sapiens]

OK I think I understand now !

I was intrigued because it said : TRANSISTOR voltmeter... so well I assumed it was some piece of test equipment dedicted to carrying god knows what particular test on TRANSISTORS !

But... given how much you insist on how it's just a bloody voltmeter, general purpose... I now realize all they meant by "TRANSISTOR" ... is simply that it made USE of transistors in it ! Probably to differentiate it from its TUBE based counterpart....

Sorry, I just was not used to major TE brands bragging on the front panel about the fact their gear used transistors... I am used to that on consumer electronics where they feel the need to write all sorts of technical sounding jargon to impress the customers but... on a professional piece of TE no, think it's the first I see that ! 

It's like Tektronix was calling say their old 547 scope : " 50% TRANSISTOR 547 ", as the full name for it, instead of just "Type 547 ".....

OK so this piece of HP TE is nothing special then...

   

It is a wee bit more complicated than that, but yes. Just as other manufacturers have used the term "Dual FET" to identify a meter whose design uses a MOSFET differential amplifier circuit which functions similarly to that of a VTVM with its high sensitivity and high input impedance. In this case it serves also to warn the user about different usage considerations, like it being portable and highly sensitive, but due to having a transistor amplifier inside, it will be sensitive to ESD or other HV sources which a passive multimeter or VTVM would normally survive.

mnem
 

Dwagon I think you are way too kind... it's just bragging / marketing !! 

Let's see what others might have to say about this...

Well, before you denigrate it further, you can try to achieve the same performance without the mentioned transistors. You do not seem to take any offence at the term VTVM and it is simply descriptive in the same way. What this little meter did was something that you could not buy at every corner, and having mastered solid-state technology to a degree where a company with good reputation did dare to place a product based on it into a very discerning market was not to be taken for granted. Many others did stick with thermionics a good while longer.

[beanflying]

In other news.......we got nominated !   
https://www.apac-insider.com/awards/business-awards/

Not sure if to accept. 

Hmm, looks like one of those types of awards. "... there are no compulsory costs in accepting a nomination or winning an award with APAC Insider. We do offer a variety of paid additional benefits for our winners,..."

Also: "Awards Coordinator - Katherine graduated from the University of Wolverhampton* with a degree in English Literature and Creative & Professional Writing." Which means at some point you'd have to listen to someone with a Wolverhampton accent, and that's a cruel thing to do to a person. it's not that people from Wolverhampton are like whining, self-pitying wretches, they just sound like it. At least they don't come from the nearby and similarly spoken Coventry, the town that gives 'accent' a bad name.

*Formerly Wolverhampton Polytechnic, formerly the Wolverhampton Tradesmen's and Mechanics' Institute. I'm not saying that the University toilets definately contain degree certificate dispensers on the walls of the cubicles, but I bet some student has annotated them to that end.

Yeah for sure you don't get something for nothing and to get your name in the spotlight is where the $ additional benefits come calling for your hard earned dosh.
Compare the flashy booklet winners list to the winners listing:
https://www.apac-insider.com/issues/business-awards-2020/
https://www.apac-insider.com/winners-list/?award=16535-2020
 

Still, it's nice that someone thought well enough of us to forward a nomination but probably will keep our head down on this one....tall poppy's and all that.

We have CANSTAR blue over here offering benefits for award payments  So the model is widespread. Providing you can make use of the 'nominated for' if there is local awareness of the award brand but dont pay them a penny IMO.

They call them 'Award Licenses'  https://www.canstar.com.au/how-we-get-paid/

[cyclin_al]

In other news.......we got nominated !   
https://www.apac-insider.com/awards/business-awards/

Not sure if to accept. 

Hmm, looks like one of those types of awards. "... there are no compulsory costs in accepting a nomination or winning an award with APAC Insider. We do offer a variety of paid additional benefits for our winners,..."

Also: "Awards Coordinator - Katherine graduated from the University of Wolverhampton* with a degree in English Literature and Creative & Professional Writing." Which means at some point you'd have to listen to someone with a Wolverhampton accent, and that's a cruel thing to do to a person. it's not that people from Wolverhampton are like whining, self-pitying wretches, they just sound like it. At least they don't come from the nearby and similarly spoken Coventry, the town that gives 'accent' a bad name.

*Formerly Wolverhampton Polytechnic, formerly the Wolverhampton Tradesmen's and Mechanics' Institute. I'm not saying that the University toilets definately contain degree certificate dispensers on the walls of the cubicles, but I bet some student has annotated them to that end.

continue reading ... it seems that the Awards Coordinator "oozes" .... 

[AaronLee]

Just found this curious little thing here :

https://www.leboncoin.fr/equipements_industriels/2008120762.htm

An old HP little gizmo, unusual to me, in like new condition for a reasonable sum (50 Euros)... in case the HP nuts on here might be interested I can help...



An HP 403A , an " AC Transistor Voltmeter ".

I have no idea in concrete terms how you would use this thing and why you would want to use it... maybe you can teach me...

Only problem is the left side of the case has been mutilated in order to fit half a dozen connectors, but if the item is rare (?), might still be worth it as it should be easy enough to repair. I mean I assume the enclosure is made of metal so should be easy to plug the hole and respray the thing, no ?

Anyway, it caught my attention, a pristine old HP thingy for only 50 Euros over here is unheard of ! 

It's a transistor successor to instruments like the 400H. I have the predecessor, so am not interested. They pretty soon were surpassed by DMM's which of course can do all the things a full VTVM will do plus current, albeit with limited frequency response. For the thing they excel at, level matching in telecom and pro audio up to a MHz or so, there soon came specialised gear from several vendors, like Wandel & Goltermann, Siemens and I believe -hp- built something too, in Scotland, at that.

I have the HP 403B, and by that time they dropped using the word "transistor" on the front. It's a good meter for my purposes. Without an option for it to be AC powered, I would probably never use the HP 403A if I had one. The HP 400H looks interesting to have, mostly for display purposes, though it would probably do just as well as my 403B for what I use it for.

[Vince]

OK I think I understand now !

I was intrigued because it said : TRANSISTOR voltmeter... so well I assumed it was some piece of test equipment dedicted to carrying god knows what particular test on TRANSISTORS !

But... given how much you insist on how it's just a bloody voltmeter, general purpose... I now realize all they meant by "TRANSISTOR" ... is simply that it made USE of transistors in it ! Probably to differentiate it from its TUBE based counterpart....

Sorry, I just was not used to major TE brands bragging on the front panel about the fact their gear used transistors... I am used to that on consumer electronics where they feel the need to write all sorts of technical sounding jargon to impress the customers but... on a professional piece of TE no, think it's the first I see that ! 

It's like Tektronix was calling say their old 547 scope : " 50% TRANSISTOR 547 ", as the full name for it, instead of just "Type 547 ".....

OK so this piece of HP TE is nothing special then...

   

It is a wee bit more complicated than that, but yes. Just as other manufacturers have used the term "Dual FET" to identify a meter whose design uses a MOSFET differential amplifier circuit which functions similarly to that of a VTVM with its high sensitivity and high input impedance. In this case it serves also to warn the user about different usage considerations, like it being portable and highly sensitive, but due to having a transistor amplifier inside, it will be sensitive to ESD or other HV sources which a passive multimeter or VTVM would normally survive.

mnem
 

Dwagon I think you are way too kind... it's just bragging / marketing !! 

Let's see what others might have to say about this...

Well, before you denigrate it further, you can try to achieve the same performance without the mentioned transistors. You do not seem to take any offence at the term VTVM and it is simply descriptive in the same way. What this little meter did was something that you could not buy at every corner, and having mastered solid-state technology to a degree where a company with good reputation did dare to place a product based on it into a very discerning market was not to be taken for granted. Many others did stick with thermionics a good while longer.

?? Denigrate ?! Where did I denigrate this thing ? I only said it was marketing ! And you just agreed with that basically ! 
Marketing that was well grounded / deserved at the time, I agree with you, but still marketing. Marketing it not always evil and BS, sometimes it just reflect useful facts ! 

See Dwagon ? Marketing, not "I am fragile transistor please baby me " warning ! 

I have the HP 403B, and by that time they dropped using the word "transistor" on the front.

There you go ! 

[mnementh]

You can have both; it is in fact pretty much the way of the world.

Just as now we take things like VSR for granted on a hand drill, it was not always so and it was worth letting a customer know about because it was in fact a better tool with more capability. Now the hot terms in such hardware are "lithium powered" and "brushless"; these things again usually mean a better tool that can do more because it is powerful and portable.

The tradeoff with "lithium power" is... expensive batteries that ensure a tool has a useful life of aboot a decade. This is clearly not advertising, but it is definitely a consideration vs AC line-powered tools which barring release of magic smoke (something which older drills that were just a switch and a motor and a gearbox never had to worry aboot) can easily last for 2 or 3 decades without further expense.

The tradeoff with "brushless" is more powerful, smaller, and more efficient, but wholly dependent upon electronics full of magic smoke and almost always a proprietary design which makes effectively a "BIC lighter" tool that is not designed to be serviced. Unlike a brushed motor design, you most likely will not even be able to hack/mod the thing to do something useful once the magic smoke escapes; it is eWaste waiting to happen the day it is made.

Whether you like them bragging aboot it or not, these are all important terms which the discerning buyer knows to look for when choosing a tool to buy, or even when choosing from multiple similar tools in his toolchest.

The point being that it still is more than just marketing wank.

mnem

[Vince]

Dwagon not sure what subject you are replying to ... BD's handdrill or the transistor meter ?! 

If the latter, then you basically agree 100% with me which I am NOT used to ! I am kinda shocked, need to go outside get some fresh air to recover from such an unexpected and improbable event ! 

Looks like moving to Brampton transformed you into a lovely  Dwagon, I think I will get used to it quickly, keep at it !! 

[Vince]

Dwagon looks like you made substantial changes to your message WHILE I was replying to the original version, you are making my life difficult you know !