Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Even when it thinks that you are on the menu?

[bd139]

If you feed it enough cats, problem solved!

[mnementh]

I think he meant the kind that would definitely keep the neighbour's cats off your garden.

I would never, ever do such a thing... Unless it was absolutely, positively amusing.   

mnem
Besides which... that's why we have ALF.

[xrunner]

Been doing a project for a local ham. He's got two Kenwood TS-2000 transceivers - one of which had burned out lamps (6) for the display. Even though they used LEDs for other indicators, they still chose to use lamps for the backlighting. The chosen color was amber, six 3mm LEDs per radio. They fit in the existing holes like they were meant to be there ... just change three resistors for proper current limiting and good to go.

But the point is, this is the last project for the old bench. After today will start breaking things down getting ready for the new one. I could have gotten it today but the WX is just bad - too much rain all day and I'm depending on a friend for transport. However - I did get the drawers new from Lowes for the bench today because they fit in my vehicle. Very nice, just need to put in some liner on the bottom.

[Specmaster]

If you feed it enough cats, problem solved!

My cat would eat the bastard [emoji41]

[Mr. Scram]

My cat would eat the bastard [emoji41]

I'm willing to pitch in for an alligator to prove or disprove this theory. Does anyone know where we could buy one and how much it costs to FedEx one?

[bd139]

Been doing a project for a local ham. He's got two Kenwood TS-2000 transceivers - one of which had burned out lamps (6) for the display. Even though they used LEDs for other indicators, they still chose to use lamps for the backlighting. The chosen color was amber, six 3mm LEDs per radio. They fit in the existing holes like they were meant to be there ... just change three resistors for proper current limiting and good to go.

But the point is, this is the last project for the old bench. After today will start breaking things down getting ready for the new one. I could have gotten it today but the WX is just bad - too much rain all day and I'm depending on a friend for transport. However - I did get the drawers new from Lowes for the bench today because they fit in my vehicle. Very nice, just need to put in some liner on the bottom.

That backlight looks better than “pissy yellow” on those rigs. My instructor had one a few months back.

[xrunner]

That backlight looks better than “pissy yellow” on those rigs. My instructor had one a few months back.

Thanks for the comment.

The owner is a bit colorblind so we went through some other color options, but what he saw was not what I saw - in case he wanted to sell them later it was best to avoid hues like this -



In the end he just said "I trust you to pick something" so I went with the amber. I do also think white looked really nice too. 

[bd139]

Makes sense. Amber always looks classy to me. Maybe because I want Elecraft kit but can't afford it



I like the FT-818ND option which is amber, blue or purple once you've found the menu, almost like a Baofeng

[Cerebus]

I think he meant the kind that would definitely keep the neighbour's cats off your garden.

I would never, ever do such a thing... Unless it was absolutely, positively amusing.   

mnem
Besides which... that's why we have ALF.

Before you do that it would be wise to check out who the neighbourhood moggie is keeping as backup:

[xrunner]

Before you do that it would be wise to check out who the neighbourhood moggie is keeping as backup:

Nice kitty kitty ... 

[mnementh]

That backlight looks better than “pissy yellow” on those rigs. My instructor had one a few months back.

Thanks for the comment.    The owner is a bit colorblind so we went through some other color options, but what he saw was not what I saw - in case he wanted to sell them later it was best to avoid hues like this -

In the end he just said "I trust you to pick something" so I went with the amber. I do also think white looked really nice too.   

 

I never was very good at choosing... though I am partial to deep prrrple. We'll see what I find when my HP 3478A gets here on Thursday; I may attack its lack of backlight in similar fashion. 

My cat would eat the bastard [emoji41]

I'm willing to pitch in for an alligator to prove or disprove this theory. Does anyone know where we could buy one and how much it costs to FedEx one?

This guy can probably make that happen. 

mnem
Hey... wait a second...

[mnementh]

Heads-up for you RF guys...



https://www.ebay.com/itm/283163572740

Programmable Step Attenuator 24 VDC 50 dB 20GHz + Probable 20GHz steaming turd, given seller's atrocious feedback. (tx, bitseeker) Look out for seller.

mnem
The Ides of October are upon me...

[Carl_Smith]

So I have some actual content for the TEA thread, rather than just lurking and making comments on other people's posts. 

Somewhere in the ballpark of 20 years ago I happened into a school auction sale and for some inconsequential amount of money became the owner of some test equipment.  Two Heathkit 10-12 oscillioscopes and four HP 3465A bench multimeters. The scopes have been sitting in the closet ever since.  Of the four meters, I got one working and had it sitting on my bench for years, but only used it occasionally, since I use my handheld meter for most everything.

But recently the one working 3465A developed a strange fault.  Instead of giving a proper reading, it would count up for a fraction of a second, and then freeze that count for a fraction of a second, then count up again.  When the reading was frozen it was not correct.  It just seemed random.  Now this meter is the piece of equiment in question from a while back when I told the story of going to the trouble of searching the net to find an owners manual and later discovering that I had a real paper manual sitting a few feet from me the whole time.

That manual has detailed schematics and test and calibration procedures that are no doubt detailed enough that I could go through everything step by step to debug the problem.  But I wasnt sure I wanted to put that much effort into a meter from the '70's that probably isn't worth much anyway.  So I figured first I'd just pull the main board out and take a look under my microscope.

I found one really nasty solder joint on a pin of an IC, on the solder side of the board.  It wasn't just a cold joint or a cracked joint.  It has some black crud on it, and what looks like tiny crystals of something around the component lead.  And some stray fuzz.  Looked pretty nasty under the microscope.





I'm not sure what the source of that crud is.  The component is just an IC and a capacitor and the board looks fine on the component side.  The location is deep inside the unit away from any holes where substances could be spilled inside and hit only that location on the board but nowhere else.  The spot is right below the battery compartment, so I considered that maybe a leaky battery somehow dripped on the circuit board, but the compartment is pretty well sealed and there was no sign of battery crud on the battery compartment over that area of the PCB.  So it's still a bit of a mystery to me how that joint came to be in that condition.

But I cleaned it up and resoldered it and now it works again. 

That inspired me to get out the next closest to working of the remaining three meters and have a crack at fixing it.  Its problem was that it worked fine but the display had no decimal point and sometimes the digits didn't light evenly.   Turns out these meters have wide ribbon cable going to the display that looks like it was made by laminating metal strips between plastic, not like modern flex circuits are made.  And the metal strips had come loose from the backer plastic at the ends.  I tried to glue some of them down but in the end gave up and just cleaned them and the connectors and carefully put it back together making sure the metal strips didn't fold back when inserting the cable into the connectors and now it works as well.   Not that I needed two more working bench multimeters...

[mnementh]

I think you've been tants-ed.

Remember, tantalum caps are an electrolytic cap. That electrolyte can creep down the component leads if they fail. You should replace that cap as PM, and closely inspect its kin for signs of deterioration.

mnem
*ZZZzzzZZZzzz...

[Carl_Smith]

Hmm....  With all the messages I see here about problems wtih tantalum caps I'm not sure why that didn't occur to me.  I guess because I think of tantalums as the drop shape caps and this one was more disc shaped.   The top side of the board looked pretty clean but I suppose it could be possible for the electrolyte to work through the joint to the other side of the PCB.

[Specmaster]

Hmm....  With all the messages I see here about problems wtih tantalum caps I'm not sure why that didn't occur to me.  I guess because I think of tantalums as the drop shape caps and this one was more disc shaped.   The top side of the board looked pretty clean but I suppose it could be possible for the electrolyte to work through the joint to the other side of the PCB.

Yes I agree, problem is that tants can come in a variety of shapes and colours  depending on the manufacturer etc at the time. I think that if you check with your printed manual it will confirm which of your capacitors are tants. On anything of that age its probably a good policy to replace all caps that are tants or Electrolytic as will almost certainly be time bombs if they have not already dryed out or leaked out.

[Specmaster]

I think he meant the kind that would definitely keep the neighbour's cats off your garden.

I would never, ever do such a thing... Unless it was absolutely, positively amusing.   

mnem
Besides which... that's why we have ALF.

Before you do that it would be wise to check out who the neighbourhood moggie is keeping as backup:

Oh I see you've met my cats Cerebus. [emoji1787]

[Specmaster]

Been doing a project for a local ham. He's got two Kenwood TS-2000 transceivers - one of which had burned out lamps (6) for the display. Even though they used LEDs for other indicators, they still chose to use lamps for the backlighting. The chosen color was amber, six 3mm LEDs per radio. They fit in the existing holes like they were meant to be there ... just change three resistors for proper current limiting and good to go.

But the point is, this is the last project for the old bench. After today will start breaking things down getting ready for the new one. I could have gotten it today but the WX is just bad - too much rain all day and I'm depending on a friend for transport. However - I did get the drawers new from Lowes for the bench today because they fit in my vehicle. Very nice, just need to put in some liner on the bottom.

That really does look quite good, never considered that colour before but does seem to suit the larger display format well. [emoji106]

[bitseeker]

Cool! More free space to fill.

You people don't miss a thing do you ? 

Not if we can help it. It wouldn't be good group therapy if we overlooked such opportunities to assist.

[bitseeker]

...

Budget notwithstanding... as much as I am into DIY, how the EFF did I manage to remain ignorant of this DIY market for so long?!?   

I guess you were probably fixing stuff, recovering from bacon overload, or covered in saw dust at the time. It happens.

[bd139]

I've got my eye on that exact enclosure for my transceiver build. Unfortunately I know I'd bugger it up doing the metal work which I am shit at and don't have the tools for it.

[bitseeker]

Been doing a project for a local ham. He's got two Kenwood TS-2000 transceivers - one of which had burned out lamps (6) for the display. Even though they used LEDs for other indicators, they still chose to use lamps for the backlighting. The chosen color was amber, six 3mm LEDs per radio. They fit in the existing holes like they were meant to be there ... just change three resistors for proper current limiting and good to go.

The new back lighting looks great. Excellent color choice and pretty even distribution.

 

I never was very good at choosing... though I am partial to deep prrrple. We'll see what I find when my HP 3478A gets here on Thursday; I may attack its lack of backlight in similar fashion. 

Well, if you're really indecisive, you could always install RGB LEDs and change the color on a whim.

[bitseeker]

Heads-up for you RF guys...



https://www.ebay.com/itm/283163572740

Programmable Step Attenuator 24 VDC 50 dB 20GHz +

That seems like a good deal. However, the guy's feedback rating is sooo low for a US seller. Although there are many factors to consider when evaluating a seller, I generally avoid domestic ones that fall below 99.8%. Even so, I've run into some bad apples. C'est la vie.

[bitseeker]

So I have some actual content for the TEA thread, rather than just lurking and making comments on other people's posts. 

Excellent.

...four HP 3465A bench multimeters.

3465A or 3456A?

But recently the one working 3465A developed a strange fault.  Instead of giving a proper reading, it would count up for a fraction of a second, and then freeze that count for a fraction of a second, then count up again.  When the reading was frozen it was not correct.  It just seemed random.  Now this meter is the piece of equiment in question from a while back when I told the story of going to the trouble of searching the net to find an owners manual and later discovering that I had a real paper manual sitting a few feet from me the whole time.

Ah, yes, I remember that manual.

I found one really nasty solder joint on a pin of an IC, on the solder side of the board.  It wasn't just a cold joint or a cracked joint.  It has some black crud on it, and what looks like tiny crystals of something around the component lead.  And some stray fuzz.  Looked pretty nasty under the microscope.

Yep, sure does look like an electrolyte spill.

But I cleaned it up and resoldered it and now it works again. 

 

That inspired me to get out the next closest to working of the remaining three meters and have a crack at fixing it.  Its problem was that it worked fine but the display had no decimal point and sometimes the digits didn't light evenly.   Turns out these meters have wide ribbon cable going to the display that looks like it was made by laminating metal strips between plastic, not like modern flex circuits are made.  And the metal strips had come loose from the backer plastic at the ends.  I tried to glue some of them down but in the end gave up and just cleaned them and the connectors and carefully put it back together making sure the metal strips didn't fold back when inserting the cable into the connectors and now it works as well.

That sounds like a pretty delicate operation. What kind of glue did you try? Cyanoacrylate? Epoxy?

Not that I needed two more working bench multimeters...

It's better than two more non-working ones.