Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

Personally I find a bin on the other side of the room is sufficient. Not as satisfying, but it improves my hand-eye coordination.

[GregDunn]

OK, as promised.  Not as satisfying as I'd hoped, but still some usable and useful additions to the shelf.  We got to the hamfest about 5 minutes before doors-open, and I had to make the decision upon entering: left, or right?  Many a TEA story has been told of the results of making that critical choice.  Happily, I chose wisely... I think.  The entire exhibition hall was crammed with vendors (guessing at least 300) but I managed to run the gauntlet and find the "scores" in about 30 minutes.  My friends, who had much more modest goals, circled the tables for about 2 hours before calling it quits.  The result: nothing earth-shattering, but I'm convinced that two of the items I found wouldn't have lasted long in today's crowd.  All the multimeters had disappeared by the time I made a second pass through the tables.

This would have been a good day for you Tek 475 lovers; I saw at least three in good working order, ranging from about $50 up.  There were also a couple of HP synthesized signal generators and some other RF gear, mostly counters.  One Commodore PET, and a couple of Franklin Aces.  Many Windoze laptops.     Far fewer stacks of old beater gear than I expected, but a couple of well-preserved Hallicrafters S-38s caught my eye.  And of course, the requisite table full of air variable capacitors and hand-wound matching coils.     Definitely the best gear selection of any fest since summer, though.  Now, the rundown....

Fluke 8600A: Yes, I already had one - you got a problem with that?     Just a great little all-purpose meter.  This one seems to have some crud on the switches, and ACV reads wildly inaccurate - which may be switches too.  It's an Option 01; the NiCds are shot, of course, but the little plastic battery holder prevented any of the electrolyte from getting onto the board.  It's very clean inside and will be about 1 kilo lighter once I extract the batteries.  It still had the original Fluke cal sticker from 1974. 

HP 3470 system: I remember our lab having a couple of these modular instruments. Very compact for a HP DMM; this one is the 4.5 digit display together with the 34702A non-current measuring DMM module.  It also has dirty switches and inaccurate ACV readings, but I doubt there's anything badly wrong inside.  It's missing the rear feet.   

Wavetek 182A: Since Wavetek had a local facility, every lab owned some of their instruments for the bench.  I'd always wanted a "real" Wavetek signal generator with a dial, for quick checking audio gear; just a bit less hassle than setting the frequency on an AWG.  This one seems to mostly work, with (all together now!) dirty switches causing the range and waveform selection to have some issues.  I'm not thrilled with whoever carved a number into the front panel with a pen, but at least they didn't obscure any of the legends with scribbles.  Something tells me this one was not calibrated.   

I'm betting all of these will need some power supply work, considering their age; but the fact that they are all operational is good.

Now the thing which I still can't believe; how much did this nice little stack of gear cost?  Out the door with a complimentary cloth bag for carrying them, total cost $32.

[med6753]

For $32 you did damn good!  And you CAN'T have too many Fluke meters. 

[med6753]

Been playing with the Siglent SDM3055 DMM. I'm definitely liking it and still figuring out all it's functions. Per Tautechs recommendation it's firmware is updated to 1.01.01.19. BTW, the user manual is incorrect on the procedure for updating the firmware but I figured it out.
     
I've let it burn in for several days to shake out any issues and there's been none. For the big test. How accurate is it? Here's the results:

AD584 Primary             SDM3055

2.50066V                       2.5006V
4.99794V                       4.9978V
7.50011V                       7.4999V
9.99691V                       9.9967V


AD584 Backup             SDM3055

2.49937V                      2.4993V
5.00030V                      5.0001V
7.50042V                      7.5002V
10.00096V                    10.0007V

It's within spec and consistently 0.0001V – 0.0002V low. Anal me wishes there was a way to “tweak” the cal but apparently that ain't gonna happen and I can live with these results. So gonna continue to figure out it's many functions.

[Brumby]

This would have been a good day for you Tek 475 lovers; I saw at least three in good working order, ranging from about $50 up.

Never in Australia.  Would love to have been able to pick one of those up.

I'm betting all of these will need some power supply work, considering their age; but the fact that they are all operational is good.

Now the thing which I still can't believe; how much did this nice little stack of gear cost?  Out the door with a complimentary cloth bag for carrying them, total cost $32.

You did good.

[Mr. Scram]

Been playing with the Siglent SDM3055 DMM. I'm definitely liking it and still figuring out all it's functions. Per Tautechs recommendation it's firmware is updated to 1.01.01.19. BTW, the user manual is incorrect on the procedure for updating the firmware but I figured it out.
     
I've let it burn in for several days to shake out any issues and there's been none. For the big test. How accurate is it? Here's the results:

AD584 Primary             SDM3055

2.50066V                       2.5006V
4.99794V                       4.9978V
7.50011V                       7.4999V
9.99691V                       9.9967V


AD584 Backup             SDM3055

2.49937V                      2.4993V
5.00030V                      5.0001V
7.50042V                      7.5002V
10.00096V                    10.0007V
It's within spec and consistently 0.0001V – 0.0002V low. Anal me wishes there was a way to “tweak” the cal but apparently that ain't gonna happen and I can live with these results. So gonna continue to figure out it's many functions.

Are you sure tempco isn't causing the difference?

[med6753]

Been playing with the Siglent SDM3055 DMM. I'm definitely liking it and still figuring out all it's functions. Per Tautechs recommendation it's firmware is updated to 1.01.01.19. BTW, the user manual is incorrect on the procedure for updating the firmware but I figured it out.
     
I've let it burn in for several days to shake out any issues and there's been none. For the big test. How accurate is it? Here's the results:

AD584 Primary             SDM3055

2.50066V                       2.5006V
4.99794V                       4.9978V
7.50011V                       7.4999V
9.99691V                       9.9967V


AD584 Backup             SDM3055

2.49937V                      2.4993V
5.00030V                      5.0001V
7.50042V                      7.5002V
10.00096V                    10.0007V
It's within spec and consistently 0.0001V – 0.0002V low. Anal me wishes there was a way to “tweak” the cal but apparently that ain't gonna happen and I can live with these results. So gonna continue to figure out it's many functions.

Are you sure tempco isn't causing the difference?

I doubt it. It's 22-23 degrees C in here with a R/H of 39%.

[bd139]

@GreggDunn : nice haul for the money. Can’t go wrong with that kit!

Wish me luck for tomorrow

[GreyWoolfe]

Solder-ily nice job mnem. 



Granddad mode again, CJ and his mum and dad are here for the weekend.

Quite a little character.

Being a grand parent is fun. After you spoil them rotten you get to hand them back to the parents as a reminder of the things they did as a child to drive you nuts. 

Must be nice.  Granddaughter lives with us, including her parents.

[GregDunn]

@GreggDunn : nice haul for the money. Can’t go wrong with that kit!

Wish me luck for tomorrow

I was pleased with the cost/benefit ratio, I must admit.     Hope you find a jewel among the junk in your search!

[bitseeker]

Now the thing which I still can't believe; how much did this nice little stack of gear cost?  Out the door with a complimentary cloth bag for carrying them, total cost $32.

Now that's a good TEA time.

[med6753]

Watch this space. This area to the right of the laptop is under utilized and in need of a makeover. Been thinking about renovations for quite a while and I've settled on what I want to do. I'm not going to reveal what that is right now as it may take months to implement it, or it might possibly not get done at all. You know how that goes. Sometimes you have big ideas but then you say screw it. Anyway, if I do go forward with my plans I will certainly post it. (I'll give one clue...it is TEA related).

[med6753]

Solder-ily nice job mnem. 



Granddad mode again, CJ and his mum and dad are here for the weekend.

Quite a little character.

Being a grand parent is fun. After you spoil them rotten you get to hand them back to the parents as a reminder of the things they did as a child to drive you nuts. 

Must be nice.  Granddaughter lives with us, including her parents.

Ouch!  That almost never works out very well. You have my sympathy.

[GregDunn]

Now the thing which I still can't believe; how much did this nice little stack of gear cost?  Out the door with a complimentary cloth bag for carrying them, total cost $32.

Now that's a good TEA time.

First steps being made already...  The Wavetek was utterly flaky when selecting waveforms and ranges, so I gently oozed some Deoxit into the switches and started working them vigorously to (hopefully) get it down onto the contacts.  I didn't really want to tear the switches apart at this stage.  Fortunately, after a few minutes, the contacts improved and I was able to reliably select what I wanted every time.  I haven't gone through the cal procedure yet, so the waveforms are a bit tatty looking; but even without any further effort, it's in decent working shape.  I even checked the PSU and voltages were well within spec.  Those big caps appear to have been replaced; they're basically supported by their leads and the solder pads have a different texture from the rest.  This one is going to be fine.

(edit) Meh.  Forgot the pic of the Wavetek internals.

The Fluke is still under advisement; it's squeaky clean inside but ACV and Ω are quite a bit off.  One NiCd is well past its sell-by date and the battery voltage with power applied only totals 4.3VDC - not even 4VDC when running on batteries alone, which trips the LO BATT indication.  I'm pretty sure this is not helping the meter's accuracy at all.  I know I shouldn't power it up with the batteries out, so I'm pondering my options for additional testing.  Ultimately, it's going to be mains-powered only (I'll never use it on battery power), so I've looked at this thread:

https://www.eevblog.com/forum/testgear/fluke-8600a-battery-power-supply-conversion/

to figure out what path I'm going to take.  I'd rather not drop a SMPS in there, but modifying it to be the same as a standard 8600A doesn't seem to be possible with the different PS transformer.  I guess the middle option is to regulate/filter the 5VDC and leave the inverter in place.  I may feed a 5V input to it for the sake of troubleshooting, because I'd rather order all the parts at once and until I know whether the PSU is causing all or part of the accuracy issues there's no point in going much further.  I'm pretty sure its switches need a good cleaning too; and perhaps that and a good 5V supply will sort it.  Stay tuned.

[mnementh]

      Watch this space.
This area to the right of the laptop is under utilized and in need of a makeover. Been thinking about renovations for quite a while and I've settled on what I want to do. I'm not going to reveal what that is right now as it may take months to implement it, or it might possibly not get done at all. You know how that goes. Sometimes you have big ideas but then you say screw it. Anyway, if I do go forward with my plans I will certainly post it. (I'll give one clue...it is TEA related).

I agree... that area of alien verdant  infestation neeeds to go... so unseemly in the manly space.  However that delicious argent representation of a classic Pontiac Tempest seems perfectly placed, and must not leave. Perhaps a compromise wherein it resides atop a nearby speaker?

I see room therein for all manner of TEA-oid mischief... even more if you're willing to relocate all that pesky service documentation  and all the at best tangentially relevant radio gear elsewhere so you can consolidate the entire space to workbench area.   

mnem
Or you could just knock out the wall and back in a full rack unit, then drywall around it. 

[bitseeker]

Hmmm, a rolling rack of boat anchors?

[bitseeker]

HP 5340A Nixie frequency counter project commencing:

https://www.eevblog.com/forum/repair/hp-5340a-frequency-counter-resurrection/

[med6753]

      Watch this space.
This area to the right of the laptop is under utilized and in need of a makeover. Been thinking about renovations for quite a while and I've settled on what I want to do. I'm not going to reveal what that is right now as it may take months to implement it, or it might possibly not get done at all. You know how that goes. Sometimes you have big ideas but then you say screw it. Anyway, if I do go forward with my plans I will certainly post it. (I'll give one clue...it is TEA related).

I agree... that area of alien verdant  infestation neeeds to go... so unseemly in the manly space.  However that delicious argent representation of a classic Pontiac Tempest seems perfectly placed, and must not leave. Perhaps a compromise wherein it resides atop a nearby speaker?

I see room therein for all manner of TEA-oid mischief... even more if you're willing to relocate all that pesky service documentation  and all the at best tangentially relevant radio gear elsewhere so you can consolidate the entire space to workbench area.   

mnem
Or you could just knock out the wall and back in a full rack unit, then drywall around it. 

The plant and documentation will move. The Pontiac GTO is safe. That Heathkit SW-7800 Receiver? I don't know what I'm going to do with it at this point. It has got to be the biggest piece of shit Heath ever produced.  I've never been happy with the performance of that receiver. And it turns out the rest of the internet agrees. It's garbage. It may wind up in the TEA closet.

Can't knock out walls....don't think the landlord would like that.   

[tautech]

      Watch this space.
This area to the right of the laptop is under utilized and in need of a makeover. Been thinking about renovations for quite a while and I've settled on what I want to do. I'm not going to reveal what that is right now as it may take months to implement it, or it might possibly not get done at all. You know how that goes. Sometimes you have big ideas but then you say screw it. Anyway, if I do go forward with my plans I will certainly post it. (I'll give one clue...it is TEA related).

I agree... that area of alien verdant  infestation neeeds to go... so unseemly in the manly space.  However that delicious argent representation of a classic Pontiac Tempest seems perfectly placed, and must not leave. Perhaps a compromise wherein it resides atop a nearby speaker?

I see room therein for all manner of TEA-oid mischief... even more if you're willing to relocate all that pesky service documentation  and all the at best tangentially relevant radio gear elsewhere so you can consolidate the entire space to workbench area.   

mnem
Or you could just knock out the wall and back in a full rack unit, then drywall around it. 

The plant and documentation will move. The Pontiac GTO is safe. That Heathkit SW-7800 Receiver? I don't know what I'm going to do with it at this point. It has got to be the biggest piece of shit Heath ever produced.  I've never been happy with the performance of that receiver. And it turns out the rest of the internet agrees. It's garbage. It may wind up in the TEA closet.

Can't knock out walls....don't think the landlord would like that.   

Floor to ceiling 19" rack ?

[bd139]

I’d say a scopemobile fits in there 

[med6753]

You're all just going to have to be patient and wait and see. All in good time.

Now I'm going to go get some sleep. 

[Cubdriver]

You're all just going to have to be patient and wait and see. All in good time.

Now I'm going to go get some sleep. 

Sleep is overrated.     (Sez me at 3 AM when I have to be up and out the door at 9.    )

-Pat

[tggzzz]

One NiCd is well past its sell-by date and the battery voltage with power applied only totals 4.3VDC - not even 4VDC when running on batteries alone, which trips the LO BATT indication.  I'm pretty sure this is not helping the meter's accuracy at all.  I know I shouldn't power it up with the batteries out, so I'm pondering my options for additional testing.

It may be simplest to just replace the NiCd cells, depending on size, capacity and whether or not they are tagged. Much to my amazement, that turned out to be the case for my TDR.

Another alternative might be NiMH, but be careful with both the charging current (NiMH needs <C/20) and claimed capacity.

[Specmaster]

I think that a 3D printer could be on the horizon for that space and the Pontiac moving right to the next parking spot.

[bd139]

One NiCd is well past its sell-by date and the battery voltage with power applied only totals 4.3VDC - not even 4VDC when running on batteries alone, which trips the LO BATT indication.  I'm pretty sure this is not helping the meter's accuracy at all.  I know I shouldn't power it up with the batteries out, so I'm pondering my options for additional testing.

It may be simplest to just replace the NiCd cells, depending on size, capacity and whether or not they are tagged. Much to my amazement, that turned out to be the case for my TDR.

Another alternative might be NiMH, but be careful with both the charging current (NiMH needs <C/20) and claimed capacity.

Not sure that is the case now. Decent nicd cells have a price premium since 2016. Not sure when you did your TDR.

I would find a way of regulating the output of the transformer myself. LT do some very low drop out regulators for not much. Pd will be quite low.

Anyway at Coulsdon now. See if I can wiggle myself in early and snag all the good stuff