Test Equipment Anonymous (TEA) group therapy thread

[bitseeker]

Yes, save it from the skip and then post it in the Buy/Sell forum. If nothing else, it could be useful to someone in the region who is repairing/restoring one.

[bitseeker]

I'll make sure to start a thread when it arrives and take lots of photos of the tear down!

Very cool! Always a treat to see such rare bits of kit.

[WastelandTek]

seriously, unless this whole thing goes mad max, in which case who cares, at some point the knobs and panel and frame  will be the most valuable part, as the kids will have recreated all the internals with improvements...pretty interested just how they are going to do the tunnels without new fab...but who knows?  maybe they will do that.

just saying...these have value

[bd139]

I reckon you could do a respectable, if not better, mock tunnel diode with some of the ridiculously high GBW opamps and some magic around them. I've built a couple of negative impedance converters in recent years and plenty of bog standard amplifiers. A carefully chosen and controlled mixture may work although off the top of my head I can't think of how to do it. I get the feeling it isn't that difficult to push past that.

[orin]

Re tunnel diodes:

Tucker still claim to have 2x152-0402-00, 5x152-0182-00 and 9x152-0081-00

http://www.etestparts.com/Search.aspx?Search=152-0182
http://www.etestparts.com/Search.aspx?Search=152-0081
http://www.etestparts.com/Search.aspx?Search=152-0402 ($25!)

Good luck finding a 152-0181-00 (1N3713) though.  (Well New Jersey Semiconductor claim to have some, but the description is wrong.  However, the linked datasheet is good.  Who know's what they have.  No doubt a ridiculous price and minimum quantity.)

You can probably get a hefty discount from Tucker for what they have if you ask - they are selling off their stock.

Edit: I have a couple each of the 0081 and 0182s should anyone need them.

[med6753]

Purchased one of these to do a sanity check on the reference I built years ago and just recently modified it to make it more accurate. I'm very pleased and surprised with the initial comparisons. I was damn close, within a few mv. The 3.5 digit DMM's were spot on. Of my three 4.5 digit DMM's (Tek 2465 scope DMM, Fluke 8050A, Mastech MS8040) the Tek was just about spot on the other two a few mv high. To some it would be "good enough" but me being an anal TEA addict I'm gonna have to go back and recalibrate until they all agree. I might never be back because it could prove to be "Mission Impossible".       

[Fungus]

Purchased one of these to do a sanity check on the reference I built years ago and just recently modified it to make it more accurate. I'm very pleased and surprised with the initial comparisons.

Do those come with a cal. certificate? Maybe it's just me but the only one I could find on eBay with a calibration certificate was this one:

http://www.ebay.com/itm/261972330425

Edit: It looks like the AD584 on these boards comes "already burned in" http://www.ebay.com/itm/311500253890   

[bd139]

I'm now down to one oscilloscope in the house and I'm feeling sad.

I've been driving classic cars (Tek/Philips analogues) for the last 25 years and all I have now is a SAIC Roewe 350 (Rigol). It does more MPG and is quite frankly a fucking amazing piece of kit and nice to drive but it has the soul of Mr Clippy and the feel of a VTech Alphabet Apple.

I want a hungry V8 roadster back even if it does bugger my wallet once a month. But it will have switches that go with a thunk! rather than a squish, a handle I can actually hook all my test leads on and no warranty void sticker.

[bitseeker]

Get the one Hydron said is going to the skip!

[bd139]

Plan!

Hydron: if you want rid of that 465, let me know 

[med6753]

Purchased one of these to do a sanity check on the reference I built years ago and just recently modified it to make it more accurate. I'm very pleased and surprised with the initial comparisons.

Do those come with a cal. certificate? Maybe it's just me but the only one I could find on eBay with a calibration certificate was this one:

http://www.ebay.com/itm/261972330425

Edit: It looks like the AD584 on these boards comes "already burned in" http://www.ebay.com/itm/311500253890   

I purchased it from Amazon and yes...it does have a calibration certificate.

https://www.amazon.com/Precision-Voltage-Reference-AD584kH-4-Channel/dp/B00Z033Y6Y/ref=sr_1_1?ie=UTF8&qid=1502845033&sr=8-1&keywords=voltage+reference

I probably paid more than I should have but I have Amazon Prime so it's free 2 day shipping. I ordered it Saturday and by Monday it was in my mailbox.

[Fungus]

I purchased it from Amazon and yes...it does have a calibration certificate.

https://www.amazon.com/Precision-Voltage-Reference-AD584kH-4-Channel/dp/B00Z033Y6Y/ref=sr_1_1?ie=UTF8&qid=1502845033&sr=8-1&keywords=voltage+reference

I probably paid more than I should have but I have Amazon Prime so it's free 2 day shipping. I ordered it Saturday and by Monday it was in my mailbox.

Ah, I see. It's written underneath. It's not shown in any photograph on eBay.

Looks like they hired the same doctor to write the label

[cdev]

Give it to the retiring tech, if he wants it. (unless he already has something he likes better, thats likely.)


Quote from: Hydron on 2017-08-13, 15:43:52

On the topics of accumulating test gear and old Tek kit, I have a bit of an problem:

- The lab tech at work has retired and left behind his Tektronix 465 scope (which he rescued from a skip (dumpster) years ago and got going)
- The company isn't likely to want to keep it, so it's probably destined for the skip again unless I or someone else rescues it a second time
- While I'd love to keep it myself, I already have 3 DSOs and no room for a big analogue beast (especially as I keep buying more kit, latest being an old tek current probe setup)

Any suggestions on what to do with it? I don't really know a lot about old Tek gear - is a 465 (in not amazing cosmetic condition) something worth trying to save? I believe it works (but needs some adjustment), and I hate to see stuff unnecessarily thrown away.

[Hydron]

Plan!

Hydron: if you want rid of that 465, let me know 

OK, will make sure it doesn't get chucked!
There may be another employee who wants it for his own use, in which case that would take priority, but otherwise I should be free to pass it onto someone who would appreciate it. Might be a few weeks with all the August madness before I can confirm which of the above is the case though.

[cellularmitosis]

Purchased one of these to do a sanity check on the reference I built years ago and just recently modified it to make it more accurate. I'm very pleased and surprised with the initial comparisons.

Do those come with a cal. certificate? Maybe it's just me but the only one I could find on eBay with a calibration certificate was this one:

http://www.ebay.com/itm/261972330425

Edit: It looks like the AD584 on these boards comes "already burned in" http://www.ebay.com/itm/311500253890   

Hi Fungus,

I ordered 6 from that seller and they all had the hand-written cal certificate.  These appear to come from the "Miller Electronics" seller on taobao: https://world.taobao.com/item/520786269812.htm

Here's my post about them: https://www.eevblog.com/forum/metrology/cheap-ebay-ad584-voltage-references-my-experiences/msg1274943/#msg1274943

[bd139]

I'm now down to one oscilloscope in the house and I'm feeling sad.

I've been driving classic cars (Tek/Philips analogues) for the last 25 years and all I have now is a SAIC Roewe 350 (Rigol). It does more MPG and is quite frankly a fucking amazing piece of kit and nice to drive but it has the soul of Mr Clippy and the feel of a VTech Alphabet Apple.

I want a hungry V8 roadster back even if it does bugger my wallet once a month. But it will have switches that go with a thunk! rather than a squish, a handle I can actually hook all my test leads on and no warranty void sticker.

Aaaand I am again satisfied.  New (old) baby pictured below:



Surprisingly working, with zero damaged or defective controls and quite happily munching up 20MHz of AWG goodness all for the princely sum of £45. And ooh ooh ooh it has 50 ohm built in termination that hasn't been blown up by the previous owner.

Embarrassingly quiet compared to my DS1054Z.

Appears to have had Ferranti as a previous owner.

Edit: will do a cal and teardown thread when I get some time.

[WastelandTek]

^^^  nice   

[bitseeker]

Very nice, indeed.

[tggzzz]

...quite happily munching up 20MHz of AWG goodness

A more revealing test  a rising/falling edge with a transition time of <1ns

... all for the princely sum of £45. And ooh ooh ooh it has 50 ohm built in termination that hasn't been blown up by the previous owner.

Embarrassingly quiet compared to my DS1054Z.

I like my 1740 too, especially the nice crisp big screen.

But I don't like the timebase board, where rotating the timebase knob causes the switch to rub against the PCB track -- and significantly abrade it. (Solution: solder a wire across the break, being careful the solder doesn't spread to the switch contacts.

The 485's (and later) Tek scopes protect the 50 ohms with a relay that pops out when overloaded.

[bd139]

I would indeed test that but I am stuck with a ~10nS rise time output here. I suppose it's a good excuse to build a Jim Williams pulse generator...

I must admit when I cracked it open, the timebase did leave me a bit "whaaat?" in this case because the board wobbles when you turn the knob. I will probably leave it be for now and just buy another 1740A to keep in the cupboard just in case

However looking at this, it's museum grade inside.  The cal seals were still present from '84. The only thing showing any wear or damage is the feet and I don't think I've ever seen scope feet that aren't knackered. It'll get some makeshift ones from whatever I can find on RS.

Alas no 485 has ever come my way for a price I'd pay or I'd snap it up instantly ... still slightly regretting selling my 475 which was in mint condition a couple of years ago. That was second best to the 485.

[Cubdriver]

The first rule of TEA - never sell!  Selling eventually leads to regret.

-Pat

[neo]

The first rule of TEA - never sell!  Selling eventually leads to regret.

-Pat

I know, i sold something a year ago so i could go to hamfest and have regretted it ever since.  I still have nightmares about what could of happened to it.
Who cares that i didn't need an AM broadcast transmitter... 

[bitseeker]

The first rule of TEA - never sell!  Selling eventually leads to regret.

Yep, done it many times. Alas, space is limited. Gotta make room for new(ly acquired) things.

First-world problems.

[Berni]

Well it is easier to sell modern cheap Chinese test gear that didn't really perform up to your expectations anyway, so you are happy to never see it again.

Its probably the hardest for the old name brand equipment. Especially when its in particularly good cosmetic condition and fully working, but at the same time you just bought a new piece of equipment that does the same job with better performance at 1/4 the size and weight.... but the old boatanchor has that lovely shiny chrome HP badge on it.

[bitseeker]

Especially when it still has its original badge on it!