Test Equipment Anonymous (TEA) group therapy thread

[Mr. Scram]

I'm not taking sides in that discussion at all but let me just say that your annoyance should have been taken to PM's rather than out in the open.

It's a forum matter, not a personal matter.

[med6753]

Actually I did consider the Siglent. But there's no stock in the USA with a 1 to 3 month order lead time. 

I can check on this if you like, that sort of lead time seems stupid for a popular model.

I would appreciate that.   Amazon says it's a 1 to 3 month order time. If there's an alternate and reliable source I would certainly consider it.

Going on their website Saelig certainly indicates 4-6 weeks delay however there's no similar indication in the USA shop:
https://store.siglentamerica.com/product/sdm3055/

Anyways, email sent to US GM to find the current state of affairs. 
Might get an answer before the end of your Friday whereas it's already Sat here.

Great! Thanks. 

[mnementh]

I don't mind that tautech brought up the Siglent because had it been available I would have ordered it. I think it has a much better display than the Rigol....which it turns out don't work anyway.

To everybody ...

I like cats but them are some ugly ass kittens. They are the new "designer" series with the pug noses and cropped ears. Some people think it's cute. It's not.   

LIES!!! This is how those cats are made... those kittens have been 'shopped I tells ya!   

Perhaps I inflamed it with the fugly kitties    Incidentally if I had to pick between the rigol or the siglent I’d choose an HP 

All I can say here is... FLUKE YOU!!! 

mnem


Just because I can.

[mnementh]

It may be obvious but the SnR in this thread is pretty low anyway. The point is that adding more noise to get rid of noise isn’t going to work. Have a word on the side or report it to mods if you have a problem.

Incidentally I don’t have a problem with it. My view on Siglent is pretty clear however.

The added noise is temporary, the improvement hopefully permanent. I feel discussing issues as adults is preferred over calling the forum police. That's more of a last resort measure and they're busy fending off the spammers anyway.

I'm not taking sides in that discussion at all but let me just say that your annoyance should have been taken to PM's rather than out in the open.

Speaking as an experienced moderator of several decades, my professional opinion is that it is NOT unreasonable to post such a complaint in thread... ONCE. A single polite rebuttal is also not unreasonable. But the back & forth thereafter should definitely have been taken to PM or if unresolved, referred to a mod.

My personal opinion here is that for the general balance of posts... Tautech is actually "present" a lot more, and generally contributes more frequently to the discussion than Mr Scram... and that this particular case was really overreacting on Mr Scram's part. Tautech's original post wasn't really unreasonable; it was clearly deliberately low-key, and I see it more as a "Come on man... I'm RIGHT HERE. You couldn't at least ask me what I have to offer before you make a new purchase like that, which is my bread & butter?"

I get annoyed when a member's primary contribution to a discussion is complaint about someone who actually bothers to be there regularly; Mr Scram definitively does contribute more than that, but honestly... not a LOT more than that. I understand that IRL often has more to do with that than intent. But the other side of that sword is the incontrovertible fact that discussions and decisions are made by those who show up and engage, not those who lurk.

This is my opinion, which I'm posting here publicly. Please respond in PM if you feel a need to express your righteous indignation. I promise I will be civil. 

mnem
"Ask your doctor if medical advice from a television commercial is right for you."

[Mr. Scram]

Speaking as an experienced moderator of several decades, my professional opinion is that it is NOT unreasonable to post such a complaint in thread... ONCE. A single polite rebuttal is also not unreasonable. But the back & forth thereafter should definitely have been taken to PM or if unresolved, referred to a mod.

My personal opinion here is that for the general balance of posts... Tautech is actually "present" a lot more, and generally contributes more frequently to the discussion than Mr Scram... and that this particular case was really overreacting on Mr Scram's part. Tautech's original post wasn't really unreasonable; it was clearly deliberately low-key, and I see it more as a "Come on man... I'm RIGHT HERE. You couldn't at least ask me what I have to offer before you make a new purchase like that, which is my bread & butter?"

I get annoyed when a member's primary contribution to a discussion is complaint about someone who actually bothers to be there regularly; Mr Scram definitively does contribute more than that, but honestly... not a LOT more than that. I understand that IRL often has more to do with that than intent. But the other side of that sword is the incontrovertible fact that discussions are had and decisions are made by those who show up and engage, not those who lurk.

This is my opinion, which I'm posting here publicly. Please respond in PM if you feel a need to express your righteous indignation. I promise I will be civil. 

mnem
"Ask your doctor if medical advice from a television commercial is right for you."

I'll just note that the thing was intended to be a remark and perhaps a polite rebuttal. Indignant denial led to what it became. I think I already pointed out it being much more than a single post to which I replied. It's a pattern and repeated behaviour in various threads across the forum which were addressed, not a single post. People who haven't been following other parts of the forums as intensely are forgiven for thinking it may have been an overreaction, but the response has in all reality been long overdue and quite conservative at that. It's tiring to see valuable information in threads consistently being drowned out by noise. That background is also the difference between lashing out in the moment and calmly expressing why it may be time to dial things back a bit, and also why a flat out denial wasn't cutting it.

I concede that people who don't have the whole picture may find the remark bothersome, or an overreaction. You know what they say about opinions.

[bd139]

Boat anchor warning

So i have got around to fixing my HP 8566B Spectrum analyzer (100Hz to 22GHz). I have been putting it off because this is a real heavyweight category boat anchor at 50kg.

The symptoms ware that upon applying power the fans spin up regardless of the power switch position and nothing lights up on the front panel. After some investigation i found that the bottom RF section does this even when nothing else is plugged into it.

...

Well after a consultation with the service manual i found a blown fuse for the 22V standby supply. Turns out this supply is responsible for switching some relays according to the front panel power switch. Yes that's right, a spectrum analyzer from 1980 has a soft power switch.

...

I couldn't find a 1A replacement fuse in the right size so i stuck in a 2A one and the symptoms disappeared and i had a LED lit on the 22V rail. Woho! So because i didn't want to leave the wrong fuse in i simply soldered the caps of the large glass fuse to a smaller 1A fuse so that it would fit inside. This is only 24V DC at low current so the large glass fuse really is not nececery.

...

Alright get the behemoth back into its rack and hook it up. Powers on just fine now. Winner winner chicken di...wait.. REF UNLOCK. You bastard.. yep waveform is definitely dancing around on the screen. At this point i was genuinely worried as the clock synthesis circuitry is a huge complicated mess spread over like 4 or 5 cards in the card cage.

...

Oh phew... turns out the problem was that the BNC jumper cable in the back that loops back the internal 10MHz OCXO reference back in has gotten a bad connection. No error messages anymore and waveform is stable. Now we do have chicken dinner 

...

Nice one on the repair and the photos 

I really really really want one of those SA's. I will need a bigger house though  first

@mnementh: that designer cat image actually made me choke on my coffee from sniggering 

[med6753]

I don't mind that tautech brought up the Siglent because had it been available I would have ordered it. I think it has a much better display than the Rigol....which it turns out don't work anyway.

To everybody ...

I like cats but them are some ugly ass kittens. They are the new "designer" series with the pug noses and cropped ears. Some people think it's cute. It's not.   

LIES!!! This is how those cats are made... those kittens have been 'shopped I tells ya!   

Perhaps I inflamed it with the fugly kitties    Incidentally if I had to pick between the rigol or the siglent I’d choose an HP 

All I can say here is... FLUKE YOU!!! 

mnem


Just because I can.

Couldn't resist.  All in good fun. 

[tautech]

Actually I did consider the Siglent. But there's no stock in the USA with a 1 to 3 month order lead time. 

I can check on this if you like, that sort of lead time seems stupid for a popular model.

I would appreciate that.   Amazon says it's a 1 to 3 month order time. If there's an alternate and reliable source I would certainly consider it.

Going on their website Saelig certainly indicates 4-6 weeks delay however there's no similar indication in the USA shop:
https://store.siglentamerica.com/product/sdm3055/

Anyways, email sent to US GM to find the current state of affairs. 
Might get an answer before the end of your Friday whereas it's already Sat here.

Great! Thanks. 

US shop has stock.
Check with an email about the real stock situation with Saelig. Maybe they just haven't updated their listing. 
If Saelig do indeed have stock, don't forget the 6% EEVblog members discount they offer. 

[med6753]

Actually I did consider the Siglent. But there's no stock in the USA with a 1 to 3 month order lead time. 

I can check on this if you like, that sort of lead time seems stupid for a popular model.

I would appreciate that.   Amazon says it's a 1 to 3 month order time. If there's an alternate and reliable source I would certainly consider it.

Going on their website Saelig certainly indicates 4-6 weeks delay however there's no similar indication in the USA shop:
https://store.siglentamerica.com/product/sdm3055/

Anyways, email sent to US GM to find the current state of affairs. 
Might get an answer before the end of your Friday whereas it's already Sat here.

Great! Thanks. 

US shop has stock.
Check with an email about the real stock situation with Saelig. Maybe they just haven't updated their listing. 
If Saelig do indeed have stock, don't forget the 6% EEVblog members discount they offer. 

Great......I will inquire directly to Saelig and see what they have to say. Thanks for your help.   

[tautech]

Random and definitely TEA related post.

Slightly depressed looking at my recent list of failures so LTspice time. LTspice playing always makes me happy.

So for the scope collectors, it's a little boring when the scope isn't doing anything and we can't all afford one signal generator per scope.

Ergo scope bouncy ball thing:

About this now I have a mo.

Have you checked out GK's pong game project ?
https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/

Wouldn't be hard to drop the paddle control so it just bounces around the CRT.

[Berni]

Nice one on the repair and the photos 

I really really really want one of those SA's. I will need a bigger house though  first

@mnementh: that designer cat image actually made me choke on my coffee from sniggering 

They are nice as long as you don't have to move them too often. And mine still has the original capacitors in it so im guessing i will have to fix it again sometime.

Oh and they make good room heaters in the winter.

[mnementh]

I'll just note that the thing was intended to be a remark and perhaps a polite rebuttal. Indignant denial led to what it became. I think I already pointed out it being much more than a single post to which I replied. It's a pattern and repeated behaviour in various threads across the forum which were addressed, not a single post. People who haven't been following other parts of the forums as intensely are forgiven for thinking it may have been an overreaction, but the response has in all reality been long overdue and quite conservative at that. It's tiring to see valuable information in threads consistently being drowned out by noise. That background is also the difference between lashing out in the moment and calmly expressing why it may be time to dial things back a bit, and also why a flat out denial wasn't cutting it.

I concede that people who don't have the whole picture may find the remark bothersome, or an overreaction. You know what they say about opinions.

Then it was still a matter of judgement; you picked exactly the wrong place and the wrong post upon which to unleash all that pent-up frustration.

Just as you've seen me apologize for going thermal on political issues, I feel your post was very much over the top in this case and the rest of the thread deserves an honest admission of and apology for that.



mnem
The rest of my opinion I will take to PM.

[xrunner]

Is the coast clear?   

I wasn't satisfied with the button response of my Agilent 54622D so I removed the front panel to clean the contacts. I really like this scope so I want it to work as good as it can.

[tautech]

Is the coast clear?   

I wasn't satisfied with the button response of my Agilent 54622D so I removed the front panel to clean the contacts. I really like this scope so I want it to work as good as it can.

Once membrane buttons go feral they can be a right PITA. Good luck on this.

What's the general consensus on cleaning fingers and the conductive rubber ?
I found you don't want to get IPA near the membrane pads.

[bd139]

About this now I have a mo.

Have you checked out GK's pong game project ?
https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/

Wouldn't be hard to drop the paddle control so it just bounces around the CRT.

I hadn't seen that actually  ... damn that's hardcore! I purposely avoided any references or googling for this one to exercise the brain. I read something about 30 years ago about how some of the earlier analogue type games worked and have been meaning to do something for years.

Good news here on that front though. I got it working. The original quadrature oscillator I found in an old opamp book was a piece of shit and kept stalling so I binned it and stuck my head in TAOE for a bit. Turned out there's a very very nice quadrature oscillator in there all along. Neat little pair of phase shifters and then an inverting amp bringing 360 degrees phase. Some value tweaking and Berkhausen was satisfied!

The whole thing is a neat little con.

The X axis is the integral of a square wave summed to a low portion of a sine wave with a phase of zero degrees. Basically a sine wibble on top of a triangle wave.

The Y axis is the integral of a slightly slower square wave summed to a low portion of a sine wave with a phase of 90 degrees. Basically a cosine wibble on top of a triangle wave.

The integrated square waves produce the horizontal and vertical movements. The sine and cosine functions result in a circle via the X-Y modulation.

The TDS210 does a fair representation of it as well believe it or not. I was quite impressed with the X-Y mode.

Anyway enough crap, quick video:



And the final breadboard (done on a solderless board just to annoy tggzzz  ).



Opamp count: 2 square wave generators + 2 integrators + 2 summing amps + 3 phase shifters = 9 opamps. All cheap ass LM358. Can probably be made single rail with LMC6482 or something and use the left over opamp as a rail splitter. Whole thing uses less than 8mA with the LM358

I'll draw up the schematic tomorrow if anyone else wants to build one.

I might add a feeper so it goes "feep" every time it hits an edge as well. Can do that easily enough by getting the edges to ring a gyrator/capacitor network in parallel (similar to an LC circuit) and amplifying it.

And on that note I'm going to bloody bed as my brain is fried   

[tautech]

Nice bd, just gotta sort that right margin !

Sleep well.

[Specmaster]

About this now I have a mo.

Have you checked out GK's pong game project ?
https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/

Wouldn't be hard to drop the paddle control so it just bounces around the CRT.

I hadn't seen that actually  ... damn that's hardcore! I purposely avoided any references or googling for this one to exercise the brain. I read something about 30 years ago about how some of the earlier analogue type games worked and have been meaning to do something for years.

Good news here on that front though. I got it working. The original quadrature oscillator I found in an old opamp book was a piece of shit and kept stalling so I binned it and stuck my head in TAOE for a bit. Turned out there's a very very nice quadrature oscillator in there all along. Neat little pair of phase shifters and then an inverting amp bringing 360 degrees phase. Some value tweaking and Berkhausen was satisfied!

The whole thing is a neat little con.

The X axis is the integral of a square wave summed to a low portion of a sine wave with a phase of zero degrees. Basically a sine wibble on top of a triangle wave.

The Y axis is the integral of a slightly slower square wave summed to a low portion of a sine wave with a phase of 90 degrees. Basically a cosine wibble on top of a triangle wave.

The integrated square waves produce the horizontal and vertical movements. The sine and cosine functions result in a circle via the X-Y modulation.

The TDS210 does a fair representation of it as well believe it or not. I was quite impressed with the X-Y mode.

Anyway enough crap, quick video:



And the final breadboard (done on a solderless board just to annoy tggzzz  ).



Opamp count: 2 square wave generators + 2 integrators + 2 summing amps + 3 phase shifters = 9 opamps. All cheap ass LM358. Can probably be made single rail with LMC6482 or something and use the left over opamp as a rail splitter. Whole thing uses less than 8mA with the LM358

I'll draw up the schematic tomorrow if anyone else wants to build one.

I might add a feeper so it goes "feep" every time it hits an edge as well. Can do that easily enough by getting the edges to ring a gyrator/capacitor network in parallel (similar to an LC circuit) and amplifying it.

And on that note I'm going to bloody bed as my brain is fried   

I might have a go and stick it on the CombiScope [emoji106]

[Cerebus]

I concede that people who don't have the whole picture may find the remark bothersome, or an overreaction. You know what they say about opinions.

The problem here is that you have previous form for this. I've seen you kick off a bit of faux moderatrixing in several threads before, with similar results and I've seen you trot out the "whole picture" line before too. I would count it an inestimable favour if you'd knock it on the head and next time you want to take issue with someone's postings in a similar vein either PM them or punt it to the moderators. I can certainly attest that Simon will take note of a "perhaps X is posting Y too often" suggestion and deal with it both effectively and quietly.

For what it's worth I personally find your attempts to impress your idea of what is and what is not acceptable a bigger generator of a worsened SNR than any of the posters I've seen it directed at. Witness this time around, that has generated upwards of 20 off-topic messages and would have generated none if you'd hit the actual moderators instead.

[mnementh]

    @mnementh: that designer cat image actually made me choke on my coffee from sniggering 

I've had it for years in my catchall bucket; it STILL makes me snigger when I scroll past it looking for something else. 

mnem
I wasn't satisfied with the throttle response I got from my Jaguar, so I made a better garrote.

[Cerebus]

Once membrane buttons go feral they can be a right PITA. Good luck on this.

What's the general consensus on cleaning fingers and the conductive rubber ?
I found you don't want to get IPA near the membrane pads.

I've found that there seem to be exactly two types of membrane buttons: ones that work forever with no maintenance and ones that have to be dismantled and cleaned regularly. Case in point, I've a Humax set top box and an LG TV. The Humax remote is 3-4 years older than the TV one and just keeps working, the LG remote has needed dismantling and cleaning every year since it was about 2 years old.

I've had the best results in cleaning the rubber parts by simple washing in the kitchen sink with water and ordinary dish detergent. Final rinse in deionised water for good measure and then drying with a clean linen cotton union glass-cloth. The board I just clean off with a 70% isopropanol/deionised water mixture.

[Mr. Scram]

The problem here is that you have previous form for this. I've seen you kick off a bit of faux moderatrixing in several threads before, with similar results and I've seen you trot out the "whole picture" line before too. I would count it an inestimable favour if you'd knock it on the head and next time you want to take issue with someone's postings in a similar vein either PM them or punt it to the moderators. I can certainly attest that Simon will take note of a "perhaps X is posting Y too often" suggestion and deal with it both effectively and quietly.

For what it's worth I personally find your attempts to impress your idea of what is and what is not acceptable a bigger generator of a worsened SNR than any of the posters I've seen it directed at. Witness this time around, that has generated upwards of 20 off-topic messages and would have generated none if you'd hit the actual moderators instead.

I guess everyone's now berating everyone else for having an opinion, with those of course being opinions themselves. If anything, the worsened SNR is caused by people tumbling over each other to add their opinion to the pile.

Nonetheless, what you call "faux moderating" is what I'd call community sense. Calling in the moderation team is like calling the police. It's a last resort and they have better things to do. Rather than calling the cops on them, I'd rather have a chat with the people who litter the community park instead. If we can't work things out, we'll go from there.

I regret the hubbub my remark has caused, as the former seems to have been entirely unnecessary.

[Specmaster]

Is the coast clear?   

I wasn't satisfied with the button response of my Agilent 54622D so I removed the front panel to clean the contacts. I really like this scope so I want it to work as good as it can.

Once membrane buttons go feral they can be a right PITA. Good luck on this.

What's the general consensus on cleaning fingers and the conductive rubber ?
I found you don't want to get IPA near the membrane pads.

If the coating on the membrane contact is wearing away, you can always use silver paint, I've seen and heard of that being done before to good effect.

[tautech]

Once membrane buttons go feral they can be a right PITA. Good luck on this.

What's the general consensus on cleaning fingers and the conductive rubber ?
I found you don't want to get IPA near the membrane pads.

I've found that there seem to be exactly two types of membrane buttons: ones that work forever with no maintenance and ones that have to be dismantled and cleaned regularly. Case in point, I've a Humax set top box and an LG TV. The Humax remote is 3-4 years older than the TV one and just keeps working, the LG remote has needed dismantling and cleaning every year since it was about 2 years old.

I've had the best results in cleaning the rubber parts by simple washing in the kitchen sink with water and ordinary dish detergent. Final rinse in deionised water for good measure and then drying with a clean linen cotton union glass-cloth. The board I just clean off with a 70% isopropanol/deionised water mixture.

Yeah that roughly mirrors my experience.
But, when the pads are stuffed, they're stuffed and as a temp fix I've even resorted to sticking bits of tinfoil on them. 

Apparently there are replacement conductive rubber pads available. SeanB pointed me to some years ago, IIRC on eBay.

[tggzzz]

Unfortunately you can "s/cat/dog/" and it is just as true.

It it piteous to see the poor things struggling to breath, or worse, struggling to keep cool on a hot day by panting.

[Cerebus]

In other news:

As I've already mentioned, I started a new (software) contract last month and, the end of October having passed, I got to cut an invoice. Now, given that I've been semi-retired for a while, and me and SWMBO have got into a routine and a place that we can live comfortably on what we already have coming in, the proceeds of my labours are largely bunce^*. Thus that invoice looks ridiculously big compared to what I actually have to spend it on. So, once I get into sufficient of a routine (and used to getting early up in the mornings) that I have some free time again I can feel some serious TEA brewing going on. That said, I haven't seen anything really tempting out there for weeks.

And on that note, taking regard of how stupidly early I've been getting up this week, I'm toddling off to bed.

^*I'm not sure if that flies east of Cornwall, so - Bunce: folding beer vouchers that are extra to one's actual requirements for them.