Test Equipment Anonymous (TEA) group therapy thread

[bd139]

That's the main reason to go to hamfests! 

[med6753]

That's the main reason to go to hamfests! 

What the hell, you can't take it with you anyway. 

[med6753]

Well, well.....Circuit Specialists responded. And I'm not surprised at their answer. No, they don't have service manuals. They suggested I contact Mastech in China directly. Oh boi!  So I did, just fired off an e-mail. Got an acknowledgement (I think) in Chinese. This should be interesting.

[mnementh]

Yeah it has been working fine for about three months now.

Edit: still considering the "fuck it" option and buying this K2 kit. This is what you get for your money:

Is it an actual "kit" that you assemble or are you just using your generic British "kit" term?

It's an actual kit of parts you have to assemble and align yourself:   

Now that's what I'm talking about; a jigsaw puzzle that DOES SOMETHING when you finish putting the pieces together! 

mnem
Heathkit can SUCK IT!

[bd139]

Well, well.....Circuit Specialists responded. And I'm not surprised at their answer. No, they don't have service manuals. They suggested I contact Mastech in China directly. Oh boi!  So I did, just fired off an e-mail. Got an acknowledgement (I think) in Chinese. This should be interesting.

Good luck getting a Mastech service manual. I have repaired a ton of their power supplies over the years and mostly have to wing it. Fortunately the power supplies are roughly the same design.

Now that's what I'm talking about; a jigsaw puzzle that DOES SOMETHING when you finish putting the pieces together! 

mnem
Heathkit can SUCK IT!

Yep exactly that. It's the ultimate Heathkit to be honest and the performance when it is built is way up there with the $3k+ bits of equipment. The price isn't that friendly but the regret of NOT buying and building a Heathkit before they disappeared off the face of the planet is much much larger. Back then my parents were poor as fuck and I burned my only income at the time (from a deceased relative's estate on a computer) so I had no chance. When I did have income it was as a student and blowing your entire student grant and loan on Heathkit on the first semester was a stupid idea. A friend of mine at the time blew his on whores so it could have been a worse investment ... plus Heathkit died before I had a job which broke even.

[tggzzz]

That was a good deal. Was that the SK stand with the HP pulse generator on it?

I enquired about the large box of "solid state devices" and was told that was already spoken for. Grr 

Not sure; I only had a chance two whizz round looking for obvious goodies. The stand was in the middle of the main hall.

There was a short queue outside at 9, and a long one at 10. Early birds and all that!

[bd139]

Yes I landed on the end of the queue at 10AM on the mark.

This I entirely blame on Nightwish's cover of High Hopes which I was getting rather into and missed the exit on the A404 leading to a 20 minute delay and being wedged behind a tractor for nearly 5 miles. By then the third car park was getting full so it was a bit of a walk 

[med6753]

Well, well.....Circuit Specialists responded. And I'm not surprised at their answer. No, they don't have service manuals. They suggested I contact Mastech in China directly. Oh boi!  So I did, just fired off an e-mail. Got an acknowledgement (I think) in Chinese. This should be interesting.

Good luck getting a Mastech service manual. I have repaired a ton of their power supplies over the years and mostly have to wing it. Fortunately the power supplies are roughly the same design.

I asked for either just the calibration procedure or the entire service manual. So if I just wind up with a copy of the cal procedure I'll be happy.

[Specmaster]

Lets hope you get something, I tried to get some parts for an Aiwa stereo from Aiwa direct and all they would do is refer me to an authorised repairers for an estimate to repair but advised that the model number had been obsolete for a number of years and so was not really worth repairing and that I ought to buying a new system 

[Specmaster]

How much would you have paid for it, bearing in mind it didn't come with the rather strange mains plug?

When I got home I realised that the Tek 191 I liberated an hour or so later does have a mains lead (But I refuse to look and see if all the pins are safely shrouded; evolution in action and all that!).

I probably would have spent £30 on it TBH untested. If it was working possibly £60. The oven was likely a risk and a headache

The 191 is rather nice too. Don't look at the mains leads on old Tek and HP kit - just pretend you didn't see them (and check the earth pin still makes contact!)

Edit: in retrospect that was the most excitement I've had all week 

Well, all bits are working, but not on all switch settings.

I offered £10 before realising it was a silent key sale, and they happily accepted.  Ditto the 191.

Sorry about that (not)!

That was a good buy, have you got the manuals and calibration data for that? If not they can be downloaded from here http://w140.com/tekwiki/wiki/191

[Inverted18650]

I have been at it again and picked up a couple more calibration unit, both substantially nicer than anything I have owned before (play theme song from the Jeffersons TV show here), and I am excited to receive them soon. Now I will be able to calibrate everything 6.5 digits and below for AC/DC Volts and Current/ Resistance/ Freq and Capacitance...pretty stoked (for the first time in several days.)

I have also been going through the manuals ( I have two hard copies) for the 5200A I listed on eBay. Part of me says keep it, and fix it so I have been reading a bit more into the "Overload always on" issue and even found a few YT videos about the issue. My gut says its an easy'ish fix (compared to the 3330B) but as of now its still for sale. What do you all think, sell it or keep it? 

 

[Inverted18650]

Have I been SHUN'D? Everyone stop talking when I popped in..

[Kosmic]

They probably all went to bed. Its around 12:30am over there (UK) 

[Inverted18650]

It was the Brit TEA crew...good eye.

[beanflying]

Just ignoring you really 11.30am here

Been for a ride on the pushbike for an hour or so to work on the expanding waistline and realizing I need to put some serious time back in again. Carbs in > Carbs out = kg gained

[Kosmic]

What do you all think, sell it or keep it?

Fix it and sell it after ? Do you need ac accuracy at home ? Also if you keep it you will need to wonder how to get it calibrated.

Personally I'm far more interested in dc accuracy. When I work with ac I don't really need my measurements to be super accurate.

[beanflying]

I watched 'some' of the defpom's videos sorting out his Valhalla AC calibrator before I got mine and made sure I got a working one instead of having to fault find

With them being such a low current output it won't take much to make it trip out on overload. Did you sort out your Thermal Camera? Clean out any fluff and lint do a search for any evil Tantalums and replace then give it another go.

[Specmaster]

It was the Brit TEA crew...good eye.

Nope, I'm still here, a bit preoccupied with other things at the mo though, none of them are TEA related really, partly because of a lack of funds and also fuck all on eBay 

[Neomys Sapiens]

Turns out that I was totally right with my assumptions about the little ACDC Electronics load (sold as power supply which doesn't output anything).
Type EL300N-A, serial BS2735. Even the designation hints at it, not to speak of the switch labeled 'Load on'.
Thank the world for it's morons and take advantage of them!

Here it is, pulling current from a fixed 12V supply that was at hand.
And my M2036 says that even the indicator is not far off.
Switched on, plugged in, set up : works.
Of course, I'll have to exercise it's current capability some more before I declare it fit for market.
And a look at the inside. Clean, no spots, no smell.

[Inverted18650]

What do you all think, sell it or keep it?

Fix it and sell it after ? Do you need ac accuracy at home ? Also if you keep it you will need to wonder how to get it calibrated.

Personally I'm far more interested in dc accuracy. When I work with ac I don't really need my measurements to be super accurate.

I bought another unit that can easily calibrate this one, if I am able to bring it back online, which is part of the reason I thought of keeping it. Non working is what $400, working and calibrated..well big difference...hum...i suppose fun as the repair might be (great to learn but it could be a huge headache too) probably best to let someone else play with it. Focus myself forward, think about new projects, right?

[Neomys Sapiens]

Oh, and in the 'List your test equipment "scores" here!' thread I did show another aquisition.
I expect drooling electronics history buffs about it!

Next in test will be the HP6825A 4Q-Power Supply. Externally, I do not see any problems except the chassis ground jack on the front being loose. But that is enough to fix that first.

[Specmaster]

Yes I landed on the end of the queue at 10AM on the mark.

This I entirely blame on Nightwish's cover of High Hopes which I was getting rather into and missed the exit on the A404 leading to a 20 minute delay and being wedged behind a tractor for nearly 5 miles. By then the third car park was getting full so it was a bit of a walk 

Yep, thats not bad but Pink Floyd's is the best IMO.

[mnementh]

You know, my second thought was nuvistors too but what threw me was the large strap attached to the top plate implying high current and nuvistors are not high current devices. So it's a tuned circuit?

   It is tuned.

Looking at the circuit it multiplies the 100MHz to 500MHz so X5. Needs some black magic to get to 500MHZ which is why it is how it is

Looks like tuned push-pull with 500MHz tank. The tank inductor is the bent bit of metal (L61/62) tuned with the butterfly cap. Input signal is coupled to it via the wire loop generating two 180 degree out of phase signals so it can shift a lot of current very quickly (required for high delta-V at 500MHz)

   So the reason that inductor looks like a tuning fork is because it's all a resonant assembly; the same way the cycloid cavity is tuned in an old RADAR magnetron?

That is fucking AWRESOME! Black Magic indeed; right up there with the Flux Capacitor! 

mnem
Jigga-WHATT?!?

[mnementh]

Well, well.....Circuit Specialists responded. And I'm not surprised at their answer. No, they don't have service manuals. They suggested I contact Mastech in China directly. Oh boi!  So I did, just fired off an e-mail. Got an acknowledgement (I think) in Chinese. This should be interesting.

Good luck getting a Mastech service manual. I have repaired a ton of their power supplies over the years and mostly have to wing it. Fortunately the power supplies are roughly the same design.

I asked for either just the calibration procedure or the entire service manual. So if I just wind up with a copy of the cal procedure I'll be happy.

Cal Prodcedure:

1) Jack up user's chair (with user in it) using air hoist.

2) Slide old MASTECH Meter out of cubby into burning bin. Take care to wrangle any leftover tentacles cables along with as well, lest they infect replacement. Slam lid on quickly and lock securely; the doomed meter may go feral at any instant.  If you don't have a locking burning bin, ABORT!!! ABORT!!! ABORT!!!

3) Slide replacement unit into cubby, deploying shiny new power cord and cables to maximize "new meter smell" dispersal, thereby triggering the "Reassurance" centers of the user's brain.

4) Jack user's chair down, then transport burning bin to burning pit IMMEDIATELY. NOMEX gloves AND HazMat tongs are recommended minimum safety gear.

5) Pour preferred accelerant into funnel in burning bin.

6) Wash hands, then crack open a cold one. Throw lit matches until burning bin ignites.

7) Sit back and relish the dying screams of yet another demonspawn sent back to the depths while sipping your favorite repast.

mnem
 

[Mr. Scram]

Well, well.....Circuit Specialists responded. And I'm not surprised at their answer. No, they don't have service manuals. They suggested I contact Mastech in China directly. Oh boi!  So I did, just fired off an e-mail. Got an acknowledgement (I think) in Chinese. This should be interesting.

Be prepared for the run-around. There's a good chance they'll just ask non-related questions or fire empty replies at you until you give up, rather than saying no outright.