Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

"And so it begins"   http://www.urbandictionary.com/define.php?term=%20And%20so%20it%20begins

Let us know your address before you are committed to the lunatic asylum.

Jackson, et al stole that quote from Babylon5 a decade earlier; he's a shameless Bab5 fanboi, and Tolkein never actually wrote those words. UD is hardly a valid reference; more like Wikipedia for the "Jackass" crowd.

Oh..... swear words.

The really annoying thing is that my first thought was that JMS wrote it. Then I googled for it, found that reference, didn't remember it from LoTR mumble decades ago, and didn't read the quote properly.

No, I haven't seen those abominable films. The less said about Bakshi's LoTR the better. I went to see Jackon's first episode[1] in the cinema, but fell asleep during the interminable boring slugfests - and haven't bothered to see any of the (five?) others.

OTOH, a couple of days ago I was wondering whether I wanted to watch Babylon5 again.

[1] as in psychiatric

[Specmaster]

Not wanting to put a damper on things, but as far as the conversation between bd139 and myself went, we were talking about desoldering stations rather soldering stations. it was about removing a multipole latching push switch from my HP 3466A which failed today. bd139 said he tried to desolder one before with a manual pump and it didn't work out, but I said I have a powered pump like the one Dave did a blog on and bd139 was going to Ebay to look?

Mind you having said all of that, as always there are some pretty things arise from the conversations in this group 

[bd139]

ebay did bad things to me 

[Specmaster]

what did you buy this time then 

[bitseeker]

I just redid the worktop of my main bench; a jobsite I was on down here they were tearing out a cashwrap with cultured marble top and I got a nice piece 92" x 29" to make the whole bench (two drafting tables side x side) into one contiguous surface.

A solid marble benchtop! Me likey (at least until the pores start to fill with "stuff" -- gotta seal that top).

You do NOT want to see what's BEHIND me... 

That depends if it's test equipment.

[bd139]

what did you buy this time then 

Wasn't me this time. SWMBO just won some garden furniture which means I've not got to do two flipping round trips from London to Swindon just to get the stuff because she won't drive on the motorway

At least it buys me some compensation credit!

[xrunner]

You do NOT want to see what's BEHIND me... 

Like Hell I don't. 

[mnementh]

Not wanting to put a damper on things, but as far as the conversation between bd139 and myself went, we were talking about desoldering stations rather soldering stations. it was about removing a multipole latching push switch from my HP 3466A which failed today. bd139 said he tried to desolder one before with a manual pump and it didn't work out, but I said I have a powered pump like the one Dave did a blog on and bd139 was going to Ebay to look?

Mind you having said all of that, as always there are some pretty things arise from the conversations in this group 

Well, on the subject of desoldering setups, MetCal is also at the top of the list. The MX-DS1 uses a venturi to generate the vacuum; which actuates in milliseconds as opposed to others which draw a vacuum with a pump. This makes it one of the best functioning desoldering heads available. Also, since it runs from air, you can remote locate your compressor and never hear the pump running. In combination with a MX-500 power unit like mine, you'll be hard-pressed to find a better setup, plus you get the best soldering station as a happy coincidence. Main downside is you need an air compressor to run it; I know that just breaks your heart.

PM user macboy and see what he's got; I know he had a full setup for sale at an awesome price not long ago that I couldn't afford due to Hurricane Harvey-related aftermath and having to pay taxes. Tell him I sent you; I'd rather see it sold than see him wait on me any longer.

ebay did bad things to me 

I just redid the worktop of my main bench; a jobsite I was on down here they were tearing out a cashwrap with cultured marble top and I got a nice piece 92" x 29" to make the whole bench (two drafting tables side x side) into one contiguous surface.

A solid marble benchtop! Me likey (at least until the pores start to fill with "stuff" -- gotta seal that top).

You do NOT want to see what's BEHIND me... 

That depends if it's test equipment.

I was hoping to not have to seal it soon... hence the shiny new cutting mat. I know... wishful thinking. 

It's WORSE than test equipment. I am a... Model Aviator. *Cue sound of frightened horses whinnying in the background*



Cheers,


mnem
With six you get egg roll.

[Specmaster]

Well, on the subject of desoldering setups, MetCal is also at the top of the list. The MX-DS1 uses a venturi to generate the vacuum; which actuates in milliseconds as opposed to others which draw a vacuum with a pump. This makes it one of the best functioning desoldering heads available. Also, since it runs from air, you can remote locate your compressor and never hear the pump running. In combination with a MX-500 power unit like mine, you'll be hard-pressed to find a better setup, plus you get the best soldering station as a happy coincidence. Main downside is you need an air compressor to run it; I know that just breaks your heart.

Hmm I've been told before how good MetCal are but they are also very expensive, perfect if you're awash with money or use it professionally but I don't think that fits many TEA people otherwise we wouldnt be looking at repairing 30 year old equipment to add to our collections. However, don't misconstrue me, I for one would love to get my hands on the newer more expensive, up market gear but unless I win the lottery, that is not going to happen 

[Cerebus]

Hmm I've been told before how good MetCal are but they are also very expensive, perfect if you're awash with money or use it professionally but I don't think that fits many TEA people otherwise we wouldnt be looking at repairing 30 year old equipment to add to our collections. However, don't misconstrue me, I for one would love to get my hands on the newer more expensive, up market gear but unless I win the lottery, that is not going to happen 

I picked up a Metcal SP-200 setup off fleabay for £60+postage a few weeks back. It's just like buying secondhand testgear except that buying a new tip is a pretty instant way to return it to good as new condition, and if you use one of the (100% compatible) Thermatronics tips it'll only set you back about £12. It is worth it for the shear pleasure of seeing any joint flow 10 seconds after you've turned the power on from cold and knowing that no matter how long you hold the iron there a joint isn't going to overheat.

[MarkL]

If you look inside the scope calibrators they’re not particularly clever little boxes. Not sure why they fetch such a high price.  You can calibrate a scope to a reasonable degree with a 10Mhz crystal oscillator and some divider ICs. Vertical cal can be done with a battery, pot and DMM. Rise time of a 100MHz scope is in the order of 3.5ns so you don’t need a crazy fast edge. I reckon you could build something superior for $5 of stuff from Tayda.

Exactly; saved me the trouble of writing that. With skill, thought and imagination, it is possible to do much more with much less.

Specialised test equipment and instructions (especially scope calibration instructions) often call for specialised test gear for two reasons:

• technicians can follow a do-what-I'm-told process to get a result that conforms to a defined corporate process
• it makes writing such step-by-step instructions much easier

Note that isn't the whole story, but it is certainly a 90% story sufficient to get a scope working again.

OTOH engineers that understand the details of what they are trying to achieve can often find other way of skinning a cat. You've mentioned a couple of techniques, but obviously there are others.

Any crystal controlled oscillator (e.g. a cheap DDS unit) is more than sufficiently accurate for calibrating a timebase.
Calibrating voltage and linearity is made easier with any form of step-based attenuator. Understanding the front-end's construction and operation means that each gain stage (actually attenuation!) means you don't need high voltages.
Probably the trickiest is tweaking to get good transient behaviour. That requires any modern logic gate plus VHF/UHF construction techniques.

Gee, I thought this thread was all about the gratuitous accumulation of test gear.  Why build something when you can have another gadget sitting in the rack.

[bd139]

I use my test gear to design and build inferior replacements! 

[bitseeker]

I was hoping to not have to seal it soon... hence the shiny new cutting mat. I know... wishful thinking. 

Yeah, definitely seal it while it's still pristine. It's still good that you have the cutting mat. Don't want to scar the stone.

It's WORSE than test equipment. I am a... Model Aviator. *Cue sound of frightened horses whinnying in the background*

Aha! Well, I've got a plane in a box waiting for me to assemble it. You know, I really need to retire so I can get more important things done.

[neo]

http://preview.tinyurl.com/tektronix7704A

I have no clue why but i am obsessed with oscilloscopes now, i know its a pipe dream to hope it goes for around a 100 but if it does is it a good bet of it working without a headache?

[tggzzz]

Aha! Well, I've got a plane in a box waiting for me to assemble it. You know, I really need to retire so I can get more important things done.

I know many people that have planes in a box. Whenever the weather looks good they take it out of the box, reassemble it, climb in and fly off for as long/far as they can.

Round here most clubs have a fixed-price-to-solo scheme costing ~£1000; and the hire cost is about £25 flying hour (including instruction if necessary). And it is bloody good fun eyeballing sheep as they whizz past at 70mph, and deliberately entering spins at 1000ft AGL

[glarsson]

I use my test gear to design and build inferior replacements! 

... or just to test and calibrate some other previously acquired test gear.

[mnementh]

I was hoping to not have to seal it soon... hence the shiny new cutting mat. I know... wishful thinking. 

Yeah, definitely seal it while it's still pristine. It's still good that you have the cutting mat. Don't want to scar the stone.

It's WORSE than test equipment. I am a... Model Aviator. *Cue sound of frightened horses whinnying in the background*

Aha! Well, I've got a plane in a box waiting for me to assemble it. You know, I really need to retire so I can get more important things done.

*Makes mental note to search for clear epoxy paint next Wednesday morning, provided I don't get a Work Order in the meantime*

A model plane... If only it were a single model ANYTHING. If it's smaller than a stove and whirrs while floating in the air exactly like a brick doesn't, I probably have it. Plus a few dozen planks as well.

Well, on the subject of desoldering setups, MetCal is also at the top of the list. The MX-DS1 uses a venturi to generate the vacuum; which actuates in milliseconds as opposed to others which draw a vacuum with a pump. This makes it one of the best functioning desoldering heads available. Also, since it runs from air, you can remote locate your compressor and never hear the pump running. In combination with a MX-500 power unit like mine, you'll be hard-pressed to find a better setup, plus you get the best soldering station as a happy coincidence. Main downside is you need an air compressor to run it; I know that just breaks your heart.

Hmm I've been told before how good MetCal are but they are also very expensive, perfect if you're awash with money or use it professionally but I don't think that fits many TEA people otherwise we wouldnt be looking at repairing 30 year old equipment to add to our collections. However, don't misconstrue me, I for one would love to get my hands on the newer more expensive, up market gear but unless I win the lottery, that is not going to happen 

I built my MX-500 for ~US$125. Bought the MX-500 power unit for $70 guaranteed working and the handle/cord/first tip for ~$US55 on fleaBay. The handle is the thing hardest to come by used in decent shape; but a new one can be bought for around $US80, then the tip for ~$US10-35 depending on your luck, new/used and the tip model. Like I suggested earlier; look up user macboy here on eevblog. He'll hook you up for a fair price.

Otherwise, build the T12 OLED controller like I outlined above. Feel free to PM me; I've done it and have learned the pitfalls.

http://preview.tinyurl.com/tektronix7704A

I have no clue why but i am obsessed with oscilloscopes now, i know its a pipe dream to hope it goes for around a 100 but if it does is it a good bet of it working without a headache?

With actual cost shipping on the auction and a little luck it might. History lists a populated 7704 showing trace went for US$102 plus $US65 shipping end of August.

Just a heads-up; if you're going to post an eBay listing, it's a LOT easier to get a short URL just by reducing it to the item number. All you need to do is cut out everything between "http://www.ebay.com/itm/" and the item number, then copy that header and the item number like so: http://www.ebay.com/itm/263255307890


Good luck (and good bidding),


mnem
Yes, you may click it.

[bitseeker]

http://preview.tinyurl.com/tektronix7704A

I have no clue why but i am obsessed with oscilloscopes now, i know its a pipe dream to hope it goes for around a 100 but if it does is it a good bet of it working without a headache?

I won't bid against you.

It looks like it's working, though the vertical was set too low for the input signal and the horizontal position was way off. Hopefully, that's all it is. However, it's also possible that the controls can't bring the signal onto the screen properly. The good news is that at least you have a visible trace that scans across most of the screen and a full complement of plugins.

Taking another look at it, it appears that the seller has one of the vertical plugins (7A26) swapped with one of the timebases (7B53A). They're in the wrong slots. That might be the only thing wrong with it, apart from the broken knob(s) on the 7A26.

[neo]

EDIT: As far as the 7704 my wallet may or may not let me go for it. I'll let you know what i intend as we approach the final hours.

[bitseeker]

You shouldn't bid until the last 2 - 10 seconds, depending on your Internet connection and/or itchy trigger finger.

[neo]

I figured it would give you a guys a shot at it if the wallet doesn't agree, but now that i think of it i could put notification here at the final hour and do that if i intend to bid. Edited original comment.

[Ero-Shan]

Lest I forget it ... Thanks very much to all of you for the warm welcome and the tips!

Please do not expect regular updates, as I have several other hobbies and activity in each of them comes in bursts.
I'd like to take some nice pictures and show them to you, but my el cheapo camera (Agfa) has a weird defect: it does not run on batteries any more. When I switch it on, it works for about 2 seconds, showing full battery status, then powers off itself and display: 'Change batteries'.  It works when I power it with a power supply @3 Volts, but the clips don't hold well at the contacts, and the cables are an extreme nuisance. That's why there were just 2 lousy pics.

Currently looking for one at the bay; might have gotten one yesterday, but as I'm not a frequent evilbay buyer (only 3 or 4 purchases so far), I simply forgot to hit the 'Confirm' button in time.  I don't need anything fancy, but it should allow decent close ups.

[Specmaster]

Ero-Shan, you're very welcome and thank you for your nice comments as well. Regard to your camera, are you certain that the batteries are good quality ones, fully charged and within their shelf life?. Unless your 3v power supply has some serious oomph behind (no current limiting etc.) then if the batteries are OK, you have some serious heavy loadings happening inside, or what's more likely is that the contacts at the other end to the ones you connect your clips to, have serious corrosion going on giving you a high resistance to current flow in the battery mode so the camera believes that they flat?

[Ero-Shan]

Ero-Shan, you're very welcome and thank you for your nice comments as well. Regard to your camera, are you certain that the batteries are good quality ones, fully charged and within their shelf life?. Unless your 3v power supply has some serious oomph behind (no current limiting etc.) then if the batteries are OK, you have some serious heavy loadings happening inside, or what's more likely is that the contacts at the other end to the ones you connect your clips to, have serious corrosion going on giving you a high resistance to current flow in the battery mode so the camera believes that they flat?

I use my lab supply, it has enough oomph. About 0.42 A when idle, maybe a 1 Amp peak when taking a picture.
The contacts (like the rest of the camera) look very new. It always ran on NiMH batteries, is configured to use them and never had any problems. (Tried with all I could muster, and alkalines, too. No avail.) As I wrote, the camera even showed them as 'full' for about 2 seconds. My guess would be very short surges in the many-Amp range which the slow meter of the PSU doesn't show. But I'm not inclined to waste more time or energy on that dud. A Panasonic Lumix DMC-FS30 should be on its way anytime now. This time I did hit the 'Confirm' button. 

[mnementh]

Odds are a fault in the charge-pump for the flash; a leaky accumulator cap (the big electrolytic in the 300-600V range) will often cause the circuit to draw excessive current, then the camera shuts down due to voltage drop. A quick test is to unsolder this cap and see if the camera powers up normally; it will sometimes display an error message related to the flash.

Alternately, it could be high IR on your NiMHs. As they age, their IR increases and they just can't deliver adequate current capacity; this can be exacerbated by a camera that needs more current due to a weak/leaky flash accumulator as above.


Try a new set of name brand NiMHs with a full charge; you'll find a use for 'em even if it doesn't cure your camera. I have a 10 year old Sony DSC-H2 that takes amazing quality macro closeups, and its 6MP resolution is PERFECT for web posting. I keep it alive with a fresh 4-pack of NiMHs every spring and then pass the old ones down to my son's game controllers, etc.

You shouldn't bid until the last 2 - 10 seconds, depending on your Internet connection and/or itchy trigger finger.

gixen.com is your friend.


http://www.ebay.com/itm/263255307890

http://www.ebay.com/itm/162712723250

http://www.ebay.com/itm/263258334708



Good hunting,


mnem
*Poit*