Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 14554481 times)

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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37275 on: August 22, 2019, 01:36:03 pm »
It's confirmed.... my hate list has earned new intensity.

Been looking at the ADSM301 and started thinking about a particular application where a larger focus range would be advantageous ... and because someone just happened to mention the ADSM302 - I found it is a better fit.

I just can't thank you all enough   ::)  ... but my bank account is cringing.

Ummm... you're welcome...?  :o

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It is too fukkin' early in the morning for dis shit...  :-DD
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Offline Brumby

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37276 on: August 22, 2019, 01:48:45 pm »
Let's just say that the best reason for me splurging on such a purchase is because I don't have one.  Any other arguments I can come up with will be excuses.
 
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Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37277 on: August 22, 2019, 01:53:08 pm »
Until you realize you need depth and therefore binoculars instead of a monocular oscilloscope.  ;D
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37278 on: August 22, 2019, 02:14:48 pm »
Until you realize you need depth and therefore binoculars instead of a monocular oscilloscope.  ;D

You get depth by moving the focal plane up and down :)

When that isn't good enough, you buy a cheap binocular microscope and find out all the ways they aren't as good as you hoped :(

I've been taking stereo photos since 1984 and have normal stereo vision (unlike 10-15 of the population), but I hate most binocular microscopes - they just don't work for me.

Having said that, I do have two which do work very well, which I got from a school closing down sale. There are no markings from which I can work out the magnification, but my estimate is one is 12* and the other 24*. On the rare occasions when a visor isn't sufficient, the 12* usually is. I very rarely need the 24*.

To my surprise, it is just about possible to use my digital camera with the microscopes.
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37279 on: August 22, 2019, 02:29:29 pm »
My TEA time is at a low ebb due to life getting in the way. Squeezed in a little CAD and 3DP to make a TEA adapter. The rear filters on this little commercial roaster are OTT on price so time to look at designing and making replacement inners to sell and maybe make a $. Airflow restriction needs to be similar to the real deal as it clogs with detritus over 30-50 roasts.

Easy transition to design when you know how and have the initial adapter on file. Another non bodge  ;)

Welcome home, bean.  ;) Kept a seat by the taco warmer for ya.  :-DD

What's this about "needing a certain amount of restriction"? Sounds like hooey to me; seems to me there's plenty of restriction in that pattern of slotted holes in the bulkhead to create a specific amount of airflow; I'm certain that is their express purpose. If not, you could print up an adjustable gate to go over the slots. No reason in the world you can't then make an airbox to fit a $6 CA9054 air filter for an F-150 in there. IIRC, those are approx 8" x 10" x 1" pleats. Oh, excuse me... approx 205mm x 255mm x 25mm pleats.  >:D
...
mnem
Fuck... I still need to pack up my Tevo Tornado... |O

5mm thick filter to play with. To much restriction and you get smokey beans as the air doesn't flow from the drum as designed :P to little and you suck the heat from the drum so you will never get them roasted in a 'normal' time.

One of the stock layers is an activated charcoal not that it matters that much as you really can't roast inside. I do roast in the shack but with the door open next to it.

Air shutter then. Make an adjustable one right in the airbox. The point is to get into a cartridge air filter that is A) Inexpensive and 2) readily available anywhere and will remain so for decades and C) larger, with deeper pleats so it takes longer to clog up. I've made dozens of custom project airboxes around those Ford & Chevy* air filters for just those reasons.  :-+                             *Why Chevy? Because the client didn't like FoMoCo and wanted it to use a Chevy air filter. :palm:

mnem
PS - I STILL think those slots are deliberately sized to do airflow metering already and you're just being anal about it.  :-DD
« Last Edit: August 22, 2019, 02:33:31 pm by mnementh »
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Offline PA0PBZ

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37280 on: August 22, 2019, 02:56:01 pm »
I activated the english subtitles and watched it  with my loudspeakers muted.

I now know why  :scared:
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Offline beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37281 on: August 22, 2019, 04:33:18 pm »
My TEA time is at a low ebb due to life getting in the way. Squeezed in a little CAD and 3DP to make a TEA adapter. The rear filters on this little commercial roaster are OTT on price so time to look at designing and making replacement inners to sell and maybe make a $. Airflow restriction needs to be similar to the real deal as it clogs with detritus over 30-50 roasts.

Easy transition to design when you know how and have the initial adapter on file. Another non bodge  ;)

Welcome home, bean.  ;) Kept a seat by the taco warmer for ya.  :-DD

What's this about "needing a certain amount of restriction"? Sounds like hooey to me; seems to me there's plenty of restriction in that pattern of slotted holes in the bulkhead to create a specific amount of airflow; I'm certain that is their express purpose. If not, you could print up an adjustable gate to go over the slots. No reason in the world you can't then make an airbox to fit a $6 CA9054 air filter for an F-150 in there. IIRC, those are approx 8" x 10" x 1" pleats. Oh, excuse me... approx 205mm x 255mm x 25mm pleats.  >:D
...
mnem
Fuck... I still need to pack up my Tevo Tornado... |O

5mm thick filter to play with. To much restriction and you get smokey beans as the air doesn't flow from the drum as designed :P to little and you suck the heat from the drum so you will never get them roasted in a 'normal' time.

One of the stock layers is an activated charcoal not that it matters that much as you really can't roast inside. I do roast in the shack but with the door open next to it.

Air shutter then. Make an adjustable one right in the airbox. The point is to get into a cartridge air filter that is A) Inexpensive and 2) readily available anywhere and will remain so for decades and C) larger, with deeper pleats so it takes longer to clog up. I've made dozens of custom project airboxes around those Ford & Chevy* air filters for just those reasons.  :-+                             *Why Chevy? Because the client didn't like FoMoCo and wanted it to use a Chevy air filter. :palm:

mnem
PS - I STILL think those slots are deliberately sized to do airflow metering already and you're just being anal about it.  :-DD

You need to RTFM and know what makes the beasty tick electronically. Unless you give it a brain transplant which for most isn't going to happen you are locked into a variable speed 12V fan and filter with resistance. These are only semi manual and if you get to far away from what it should sense internally the electronics throws a hissy fit  ;) There is an aftermarket Arduino based board for them but only for the nerds not the masses.

My bigger roaster runs a mechanical gate and fixed 240V fan and exhausts all the fumes and smoke past a cyclone to the outside. This is fairly normal with the bigger ones. Smoke and smell are part of the game.
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37282 on: August 22, 2019, 05:32:37 pm »
You mean this stupid thing has a B/MAP sensor in the outlet to tell it when the filter is clogged? Then your job is easier, not harder. Make the air damper, then run it wide open. Close the damper bit-by-bit until the software is happy. Put a screw in the damper & forget it. :D I promise you... if an idiot like me can put TPI on a '60s B-Body Chrysler, you can outwit that too-smart-for-its-own-good coffee-bean tormenter. :-DD   

Then you get the joy of cheap air filters for a lifetime... plus the smug satisfaction of out-smarting those assholes who tried to lock you into their "product supply chain" like fucking Epson and their inkjet cartridges that cost 10x as much as gold for the net product. ::)

The only thing it'll cost you is some filament... seems like a no-brainer to me...  :-//

mnem
You can do them. >:D
« Last Edit: August 22, 2019, 05:36:33 pm by mnementh »
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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37283 on: August 22, 2019, 08:58:17 pm »
Tggzzz, per your recommendations I concentrated on the discrepancies noted on U780 pins 1 and 3.

I pulled and tested R791,792, 793, 773, and 781. All good. Pulled and tested CR781 on the Fluke 87 diode test and it shows .25V rather than normal .5V. I looked it up and it's a “Tek special” diode with no cross reference so I'm assuming it's OK. I also pulled and tested on my little component tester Q794 and Q792 and it at least shows them to be NPN so I'm assuming right now they are OK.

Here's the pulse at both tunnel diodes CR772 and CR762. 0.2mV/1ms.



Started looking at U740 and I think I found some issue. This is pulse at TP5 as well as at CR751. 5MV/2ms and 5MV/1ms. That doesn't look right at all. Mostly ripple noise. Quick check of other pins of both U740 and U738 are showing same crap. I'm going to pick up in this area in the AM. It definitely looks fubar. Do you agree?  :-//





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Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37284 on: August 22, 2019, 09:08:01 pm »
Doesn't look too good. LMK if you need tunnel diodes. I have some matched pairs here I'm saving for a rainy day.
 

Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37285 on: August 22, 2019, 09:25:06 pm »
Doesn't look too good. LMK if you need tunnel diodes. I have some matched pairs here I'm saving for a rainy day.

This 485 has 3 tunnel diodes. I haven't checked to see if they are the same P/N as my 465 parts mules. But I don't think they're bad. Something is not right around U740 and U738 IC's. I suspect I'm missing a voltage.
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Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37286 on: August 22, 2019, 09:56:28 pm »
The test gear drought has ended. Just bought another scope  :-DD

So the HP collection grows. I own an HP 1740A. Powers up untested. No trace. All knobs intact. Looks like it might just be rammed in XY mode. Fingers crossed  :scared:

Needs new feet and worst case it's strip and sell parts off.

Edit: just realised I'm turning into HP fanboy. That's err 3x power supplies, 1x function generator, 1x scope, 1x meter, 1x calculator now  :-DD (I won't mention the printer or the shonky Elitebook though).

Edit 2: had one of these before for ref. Picture of the last one I restored:

« Last Edit: August 22, 2019, 10:17:18 pm by bd139 »
 

Online tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37287 on: August 22, 2019, 10:47:27 pm »
Pulled and tested CR781 on the Fluke 87 diode test and it shows .25V rather than normal .5V. I looked it up and it's a “Tek special” diode with no cross reference so I'm assuming it's OK.

Yes, it is a G866 germanium diode, and that value is plausible. See the  tektronix_Xref_sm.pdf file on tekwiki.

I'll look at the other things tomorrow, with luck.
« Last Edit: August 22, 2019, 10:49:11 pm by tggzzz »
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37288 on: August 22, 2019, 10:59:39 pm »
The test gear drought has ended. Just bought another scope  :-DD So the HP collection grows. I own an HP 1740A. Powers up untested. No trace. All knobs intact. Looks like it might just be rammed in XY mode. Fingers crossed  :scared: Needs new feet and worst case it's strip and sell parts off.
Edit: just realised I'm turning into HP fanboy. That's err 3x power supplies, 1x function generator, 1x scope, 1x meter, 1x calculator now  :-DD (I won't mention the printer or the shonky Elitebook though).
Edit 2: had one of these before for ref. Picture of the last one I restored:

Ooooh... lookit all the pretty colors!!!  :-DD

mnem
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« Last Edit: August 22, 2019, 11:01:18 pm by mnementh »
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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37289 on: August 22, 2019, 11:31:23 pm »
Pulled and tested CR781 on the Fluke 87 diode test and it shows .25V rather than normal .5V. I looked it up and it's a “Tek special” diode with no cross reference so I'm assuming it's OK.

Yes, it is a G866 germanium diode, and that value is plausible. See the  tektronix_Xref_sm.pdf file on tekwiki.

I'll look at the other things tomorrow, with luck.

I measured the DC voltages at U740 expecting something to be missing but apparently not. This is what I got:

Pin 1 +6.321V
Pin 2  +7.036V
Pin 3  +6.712V
Pin 4  +4.933V
Pin 5  +9.917V
Pin 6  +9.917V
Pin 7  +8.697V
Pin 8  +11.186V
Pin 9  +11.186V
Pin 10 +4.933V
Pin 11 +9.230V
Pin 12 +9.044V
Pin 13 +7.828V
Pin 14 +6.326V
Pin 15  0
Pin 16 +7.828V

Edit...I thinking that tunnel diode CR751 is in fact duff but I'll wait and see what you get in the AM.
« Last Edit: August 22, 2019, 11:41:00 pm by med6753 »
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Offline 0culus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37290 on: August 22, 2019, 11:37:36 pm »
The test gear drought has ended. Just bought another scope  :-DD

So the HP collection grows. I own an HP 1740A. Powers up untested. No trace. All knobs intact. Looks like it might just be rammed in XY mode. Fingers crossed  :scared:

Needs new feet and worst case it's strip and sell parts off.

Edit: just realised I'm turning into HP fanboy. That's err 3x power supplies, 1x function generator, 1x scope, 1x meter, 1x calculator now  :-DD (I won't mention the printer or the shonky Elitebook though).

Edit 2: had one of these before for ref. Picture of the last one I restored:



Now you need a 1727A. Unfortunately they are not common at all. I was lucky to acquire one in such good shape.
 

Offline beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37291 on: August 23, 2019, 01:55:14 am »
You mean this stupid thing has a B/MAP sensor in the outlet to tell it when the filter is clogged? Then your job is easier, not harder. Make the air damper, then run it wide open. Close the damper bit-by-bit until the software is happy. Put a screw in the damper & forget it. :D I promise you... if an idiot like me can put TPI on a '60s B-Body Chrysler, you can outwit that too-smart-for-its-own-good coffee-bean tormenter. :-DD   

Then you get the joy of cheap air filters for a lifetime... plus the smug satisfaction of out-smarting those assholes who tried to lock you into their "product supply chain" like fucking Epson and their inkjet cartridges that cost 10x as much as gold for the net product. ::)

The only thing it'll cost you is some filament... seems like a no-brainer to me...  :-//

mnem
You can do them. >:D

It runs an internal temperature sensor that drives the brain which within the set parameters you can vary airflow and power if it detects temperature ramps outside what it has stored it alarms (manual cancel) or if it is to far outside 'normal' it dumps the roast with no warning. Basically running it with a gate and not following along with the fan speed changes would screw with it's brain. Filter material in bulk is cheap and pre filtering with some of the s/steel mesh I got for the job can be cleaned in coffee machine cleaner and re used forever.

The filter needs to stay to keep it portable without external ducting. Even on 250g of beans the smoke level is a lot.
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37292 on: August 23, 2019, 02:09:15 am »
But won't that also f*** with the airflow? And non-pleated filter elements clog exponentially faster. The way you were talking before, it sounded like you felt the charcoal was unnecessary. Or is the plan to make a pre-filter element that's easy to clean before every roast, thereby extending the life of their "special" filter? Sortof like the SS coffee filter used for modern drip coffeemakers...?

It seems to me that no matter how it "senses" the airflow of the tiny filter they used, you should be able to simulate it using a larger filter with an air shutter to modulate flow. That original filter in new condition will flow a fixed volume that does not change appreciably from beginning to end of the cycle. There should be no reason you can't approximate that with something more cost-effective than their little cartridges; I've done exactly that on dozens of different kinds of airflow-intensive machinery in manufacturing & food-processing applications.

mnem
 :-//

« Last Edit: August 23, 2019, 05:36:16 am by mnementh »
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Offline beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37293 on: August 23, 2019, 02:20:34 am »
It doesn't detect airflow it detects temperature rate of rise inside the drum with looking at a sensor. To high a rate and something is wrong so alarm or dump the load.

Making baffles and external filters is not KISS and as such is not suitable to make and potentially sell. If you look at the likely cost of the mods you would be into it to the tune of multiple years of roasting to even get close to 'saving' a $.
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Offline bitseekerTopic starter

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37294 on: August 23, 2019, 03:29:42 am »
The test gear drought has ended. Just bought another scope  :-DD

So the HP collection grows. I own an HP 1740A. Powers up untested. No trace. All knobs intact. Looks like it might just be rammed in XY mode. Fingers crossed  :scared:

Congrats!

Quote
Edit: just realised I'm turning into HP fanboy. That's err 3x power supplies, 1x function generator, 1x scope, 1x meter, 1x calculator now  :-DD (I won't mention the printer or the shonky Elitebook though).

Welcome to the club. There are worse things you could turn into. ;D

I just added an HP 8560E with tracking generator to my HP stable. :-+
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37295 on: August 23, 2019, 05:41:52 am »
It doesn't detect airflow it detects temperature rate of rise inside the drum with looking at a sensor. To high a rate and something is wrong so alarm or dump the load.

Making baffles and external filters is not KISS and as such is not suitable to make and potentially sell. If you look at the likely cost of the mods you would be into it to the tune of multiple years of roasting to even get close to 'saving' a $.

Okies... The closest I've ever come to what you're doing is chain-fed air-bakery; it certainly isn't as hostile an environment as what you're doing. I'll defer to your greater experience in heat-treated bitter herb. ;)

Hope you get what you're looking for!  :-+

mnem
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37296 on: August 23, 2019, 05:52:51 am »
I just pulled together my Taxes for last year. I spent almost $200 just on probes/test leads and stuff to make test leads/patch cables. Another $300 on meters. And $900 on wrenches and power tools. 

mnem
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Online tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37297 on: August 23, 2019, 07:58:59 am »
Started looking at U740 and I think I found some issue. This is pulse at TP5 as well as at CR751. 5MV/2ms and 5MV/1ms. That doesn't look right at all. Mostly ripple noise. Quick check of other pins of both U740 and U738 are showing same crap. I'm going to pick up in this area in the AM. It definitely looks fubar. Do you agree?  :-//

All stuff around that area, i.e. before c761/r761 does not depend on whether or not it is triggered; u780 is irrelevant.

u740 etc are classic long-tail pair differential amplifiers. The inputs are differential voltage inputs, the outputs are differential current outputs. If the input voltages are equal, the output currents should be equal. The output currents are converted into input voltages for the next IC by resistors, i.e. r731, r736, then r745, r746, r749 , then r751, r752 plus others around cr751. Using a single-ended scope probe can only measure the differential output current indirectly! The differential input voltage should be <100mV for linear operation; if it is more than 200mV the outputs will be fully saturated/off.

A good way to test that is to use the 1kHz cal out driving the external trig input (as per fig 6 top left). You should see a square wave on u740.5 and u740.9.  At those two points I see unequal 200mV-800mV square waves, and the relative amplitude depends on the position of the trigger level control.

If you don't see those square waves, then start at u730.14, u730.16 (inputs) then u730.5, u730.9 (outputs), then u738, then u740.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline Zucca

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37298 on: August 23, 2019, 08:04:51 am »
For European TEA, if you need a cheap (<400€) 66309D please join me here
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Offline BU508A

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #37299 on: August 23, 2019, 08:40:57 am »
The test gear drought has ended. Just bought another scope  :-DD

So the HP collection grows. I own an HP 1740A. Powers up untested. No trace. All knobs intact. Looks like it might just be rammed in XY mode. Fingers crossed  :scared:

Congrats!

Quote
Edit: just realised I'm turning into HP fanboy. That's err 3x power supplies, 1x function generator, 1x scope, 1x meter, 1x calculator now  :-DD (I won't mention the printer or the shonky Elitebook though).

Welcome to the club. There are worse things you could turn into. ;D


Yes. For example, one could turn into a R&S fanboy ...  :scared:    :palm:
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 


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