Test Equipment Anonymous (TEA) group therapy thread

[Berni]

Yeah some of the plastic that HP used has now become really brittle. The front panels on HP E3630A PSUs and similar are made from the same crap and they have clips to hold it together so you inevitably break one when taking it apart.

Also the square button caps are a similar plastic. I had a few buttons fall apart because the tight switch shaft inside has split them in two.

[Specmaster]

Wow, I'm off line for 2 days and it's taken me over an hour to catch up. Can't possibly respond to everything other than to say that my Fluke 8800A has very high input impedance and it reads wacky too with nothing connected. It's normal.

The reason for my absence? Was with the lady from yesterday afternoon until I got home a while ago. For the past few months she's had some chronic pain in the right side of her chest. She had colon cancer about 10 years ago but tests conducted just last year revealed that she was clear. Obviously we were afraid that the cancer had returned.  Some tests including a CAT scan revealed nothing. Today I had to take her for an endoscopy in NYC. The result? An inflamed esophagus treatable with medication. It was a great relief for both us. 

Came home tonight fighting NYC rush hour traffic. Normal 2 hour drive took over 3 hours.   

 

Lucky it only added an extra hour, it's usual over in big cities like London to add 2 hours.

[Specmaster]

         

So after reading the manual again quickly to see how it runs in defaults... I tried again after letting it idle 30 minutes to warm up with leads shorted so auto-zero could do its thing. Shorted seems pretty good... so tried against the AD584LH reference. 10V reference here is bouncing between 10.004-005 on the Fluke, and 2.5V reference stable at 2.5020 on the Fluke.

When I first shorted out the leads in OHMS, it read ~6ohms; after I finished with REFERENCE DCV, I tried again in OHMS and it read 0.0967something, which is not far off the ~0.10 ohms shown for those leads shorted and plugged into the Fluke and the DE-5000. Curious, I tried a little percussive diagnostics; and bam, resistance jumped up around 11 ohms. Looks like I have an intermittent in the resistance section, or a cruddy F/R switch.

But... the fact it reads DCV so close indicates to me the internal reference voltage is pretty close to dead nuts... that means everything else can be made right.

EDIT: I took a quick look inside, but found no obvious simple culprit. Will need to do some live percussive diag when I have time, but RIFAs lurking under the GPIB connector and power switch are visibly crazed, so I'm probably going to back-burner this until replacements can be installed.

mnem
*ZZZzzzZZZzzzZZZzzz...*

It's probably just crud in the front /rear switch give it a shot of deoxit

[Martin.M]

directly after breakfast I have buyed this ..
(it will make some differents here)
Martin

[Ero-Shan]

directly after breakfast I have buyed this ..
(it will make some differents here)
Martin

A-ha! I was looking at this for a few days. After the price soared this morning and as I have no real use for it (and couldn't find a manual anywhere), I decided to skip it.

Congratulations and hope it works!

This was about the only interesting thing in the last weeks. Its a terrible dearth on german ebay. 

[Ero-Shan]

Just a heads up for anyone with a 3478a. If you do replace the RIFA don’t try and take the extender bar off the power switch. Unscrew the switch and pull the whole thing out. They are brittle as feck! Yes I broke the switch. 

Had to epoxy and pin it.

Talking about brittle plastics ... I took a brief look at another 100 MHz CRO, a Philips PM 3262. Since it worked (not perfect, but Ok), I started to clean it. When I tried to pull the caps from the knobs (with my fingernails), they simply disintegrated. Grrr.
Of course they are of a slightly different color than those at all my other Philips scopes.

[bd139]

Philips have the worst plastics. Like really bad. I have had at least two Philips things arrive in pieces.

[Martin.M]

This was about the only interesting thing in the last weeks. Its a terrible dearth on german ebay. 

no, there was a 8300A, this is now on my restoration table 
greetings
Martin

[Ero-Shan]

After three weeks of being woken by horrible noise I finally put my 'clock radio' on the lab bench.
The radio part is a Kenwood KA-46R receiver, and it could not be tuned anymore. Even with the station search running through the whole FM band, the tuned frequency evidently stayed the same (off center on a classic music station, terribly distorted and noisy).
Only a year ago I had to replace the supercap in that device, as it kept losing the chosen frequency (with almost the same result).
In order to ending my sleep on a better note, I had to open it again. Doing a bit of mnem's percussive diagnostics or 'knock, knock knocking on PCBs', there was a definite answer.
The case has a removable plate on the bottom that gives access to most of the PCB's solder side. But not at the RF section. Silly me thought it must be there and I wanted access to the whole PCB. Big mistake. You have to disassemble the whole thing then. The ribbon cables from the control section at the front are in clamps (cheap shit, if you ask me), but the cables of the power switch and a ground wire are soldered. Didn't have to unsolder the power cable though, as it snapped off right where the insulation ended. Stranded wires with stiff isolation and tinned ends always break there ...
Anyway, I wouldn't have needed all this, as the cold solder joint had been in the easily accessible portion of the PCB. After soldering and repairing the damage I'd done by my disassembly, the little old Kenwood does play music once again.

After all the repair debacles lately, I'm glad to have finished this one, even if it was basically a no-brainer.

[Specmaster]

@mnementh.
I've just seen your photos on a monitor and caught that extra bit of visual information and the voltage spec is spot on and is conformed by the Fluke so you can almost certainly take it for granted that the resistance is likewise bang on the money. With this in mind I decided to experiment with mine and I discovered that under the right conditions you can get a resistance reading like yours if the shorting of the probes / croc clips is not quite as good as it could be because of a built up of grease and crud on the contact surfaces. To make it as realistic as I could I too got my AD584-M out and did the same as you, voltages first and they were OK but when I shorted the probes in 2W resistance I got the result as shown in picture HR, giving the probes a wipe resulted in the reading LR.

So if you go on a hunt looking for problems inside, then the chances are that you won't find anything wrong as all to often we tend ignore the obvious when it is staring us in the eye.

[Ero-Shan]

This was about the only interesting thing in the last weeks. Its a terrible dearth on german ebay. 

no, there was a 8300A, this is now on my restoration table 
greetings
Martin

I didn't see that! That's not fair! Seems I have to work on my search string.

Granted, there was also a Racal-DANA Nixie meter (where the seller used screws to connect to the terminals, gah!), but my snipe landed 50 cents short.

And I'm waiting for a parcel that sits in Dortmund.

There's also the usual collection of over-prized Hameg, Grundig and Philips scopes, but suffering from TEA for quite a while now, I'm looking for something stronger than that or just another DMM. 

[Specmaster]

The UK Ebay is about the same as well, sometimes I wonder if we haven't sucked up most good things between us already, especially those with large amounts of shelf space or lab space to fill tend to grab almost anything that looks half decent to add to their growing collection of instruments that will more then likely, once repaired never be used again.   

[GreyWoolfe]

Just a heads up for anyone with a 3478a. If you do replace the RIFA don’t try and take the extender bar off the power switch. Unscrew the switch and pull the whole thing out. They are brittle as feck! Yes I broke the switch. 

Had to epoxy and pin it.

That's exactly what I ended up doing both when doing the RIFAs and when putting on the replacement buttons.  The extender bar for the front/back switch actually came off and went back on very easily.

Yeah some of the plastic that HP used has now become really brittle. The front panels on HP E3630A PSUs and similar are made from the same crap and they have clips to hold it together so you inevitably break one when taking it apart.

Also the square button caps are a similar plastic. I had a few buttons fall apart because the tight switch shaft inside has split them in two.

My 3478 had a broken power button.  When I received the replacements, I tried to gently remove the button on the front/back switch and it simply came apart.  My HP 3312A function generator has 3 broken buttons.

[Martin.M]

I didn't see that! That's not fair! Seems I have to work on my search string.

I have sent you a message with a search string.
lG Martin

[bd139]

Knowing what search strings to use is where ebay power comes from 

[SLJ]

Old stuff... lots of old stuff.
Was cruising around the web and ran into a Supreme tube tester from 1934. Got me hooked. Back then test equipment design was as much an art form as it was function.


Years later the radio collection has fallen by the wayside and the piles of antique and vintage test gear have totally taken over.


Here's just the Supreme portion...
http://www.supremeinstruments.org

and my wife thought I had too many radios... 

[Martin.M]

and my wife thought I had too many radios... 

the old radios are sometimes out of WAF (womens acceptance factor) ...

[bd139]

Ugh got to rant this out as much as possible or I'm going to explode.

I sold the D83's the other day because I don't have the time to deal with them at the moment to be honest, nor the space. Too many projects. There I said it. Person just turned up to collect them and left empty handed. So what went wrong:

1. They thought they were smaller 
2. They thought a carrier bag was enough to carry them in on a train all the way home about 30 miles
3. They couldn't even lift one of them up 
4. They didn't actually know what they were but looked interesting as a film prop 

So basically           

Millenial media studies student. 

Outbound message:

[med6753]

That's right, fuck'em.  Freakin idiot.   

Whenever I list something for sale on local Craigslist I always post my Town. I recall getting a response from someone who was located in Yonkers which is about 60 miles away. (Don't recall what the item was but it was no more than $40). Anyway, in our e-mail correspondence I told him several times where I was located. No problem, he wanted it. Then all of a sudden I get an e-mail saying he didn't realize exactly where I was and could I meet him somewhere halfway or pay for his gas. Uh, no.    Needless to say he bailed. Asshole.   

[med6753]

and my wife thought I had too many radios... 

the old radios are sometimes out of WAF (womens acceptance factor) ...

Impressive German radios. 

[mnementh]

Shi*... Shi*... Shi*... Where the FU** IS IT?!?
   
 Oh... okay... there it is...

It's not packed like Keysight wanted it to be (they don't like bubble wrap, they call it californian air -never heard of that term), but from a practical point of view it's packed very well and should be fine -distance between device and the outer cardboard package looked decent to me.      Ah, the link to the Keysight packaging guide (german): LINK 

Oh, I wasn't complaining.... I was having fun, teasing with the "big reveal". Like my Fluke 189 from Express_Auctions (2nd pic above), it would've survived even those Dingle Express carriers who chuck it over the fence. 

@mnementh.
I've just seen your photos on a monitor and caught that extra bit of visual information and the voltage spec is spot on and is conformed by the Fluke so you can almost certainly take it for granted that the resistance is likewise bang on the money. With this in mind I decided to experiment with mine and I discovered that under the right conditions you can get a resistance reading like yours if the shorting of the probes / croc clips is not quite as good as it could be because of a built up of grease and crud on the contact surfaces. To make it as realistic as I could I too got my AD584-M out and did the same as you, voltages first and they were OK but when I shorted the probes in 2W resistance I got the result as shown in picture HR, giving the probes a wipe resulted in the reading LR.

So if you go on a hunt looking for problems inside, then the chances are that you won't find anything wrong as all to often we tend ignore the obvious when it is staring us in the eye.

Naaahhh... I confirmed it ex-situ by unplugging the leads from the 3478A and plugging them directly into first my Fluke and then my DE-5000, both of which returned stable results at approx 0.10 ohms. Then I confirmed it in-situ by plugging them back into the 3478A again and rapping on the top of the box. Resistance shown fluctuated wildly with no change other than rapping on the box, and it responded similarly, with similar values, with leads plugged into the front or the back jacks. RT505 looks possibly overheated, but I need schizzmatics (Just received; thanks Cerebus!  ) and more importantly, time to work on it.

I should be working on my taxes right now as deadline is Monday, but I have a pounding migraine and wanted to relax a few minutes with my friends while I finish my coffee. 

Just a heads up for anyone with a 3478a. If you do replace the RIFA don’t try and take the extender bar off the power switch. Unscrew the switch and pull the whole thing out. They are brittle as feck! Yes I broke the switch. 

Had to epoxy and pin it.

That's exactly what I ended up doing both when doing the RIFAs and when putting on the replacement buttons.  The extender bar for the front/back switch actually came off and went back on very easily.

Yeah some of the plastic that HP used has now become really brittle. The front panels on HP E3630A PSUs and similar are made from the same crap and they have clips to hold it together so you inevitably break one when taking it apart.

Also the square button caps are a similar plastic. I had a few buttons fall apart because the tight switch shaft inside has split them in two.

My 3478 had a broken power button.  When I received the replacements, I tried to gently remove the button on the front/back switch and it simply came apart.  My HP 3312A function generator has 3 broken buttons.

I shall heed your warnings when I do get into it.

Right now the sea (of tax paperwork) sings its siren song, and I must answer the call...

mnem
Odysseus can suck it.

[Cerebus]

...
3. They couldn't even lift one of them up 
...
Millenial media studies student. 

Bah! Send 'em all down the salt mines to build up some strength (and once they're fit and strong, conscript 'em into the army and invade somewhere).

When I were young, I though older people were curmudgeonly because they
were innately nasty, miserable people. I didn't realise that they did it because
it's so much fun!

[bd139]

"I'll have a tall latte" said the media studies student, fearful of the weight of a grande.

And yes it is so much fun

Edit: I just tried. My 14 year old (girl) can lift them up 

[med6753]

When I were young, I though older people were curmudgeonly because they
were innately nasty, miserable people. I didn't realise that they did it because
it's so much fun!

Amen Brother! 

[Martin.M]

Bah! Send 'em all down the salt mines to build up some strength (and once they're fit and strong, conscript 'em into the army and invade somewhere).

You know the System of Electrometer?  Give him al lot of Electro up to the Voltage he will jump at minimum one Meter