Test Equipment Anonymous (TEA) group therapy thread

[Martin.M]

this help me a lot, thank you very !

The AC switch is still there, but the larger one is missing, also all black banana there.
Reconstruction.

I will order 10 pcs old black banana plugs, the small version, this will do.
The int/ext. switch is a 6x changer, 6x3
and a 100k in series with one of the plugs.

[factory]

They are not banana jacks, attached are some pictures saved from the web, not mine.
It also seems they moved the terminals around when they changed the mains socket type, I don't know which you have, I haven't got any internal pictures of the older one.

David

[Martin.M]

Thank you again.

I will test now PSU + 1kHz intern present.

here is a picture of the problem

[Martin.M]

I solded 2 short cables on board A200PSU to connect the +12V and -11V to the internal oscillator.
The power in from this was interrupted by the missing int/ext switch, now the osc. get voltage and works.

Tested C : yes, this apparatus is nice testing C
except: The instrument goes always to the right direction, when zero it goes near to zero, but never to the left side.
The both gas bulbs are working.

L: comming soon.

[factory]

An earlier one, shame someone removed all the terminals & the switch, the terminals might be a YHP custom part, as they give non-standard part numbers. I can't understand why they also removed the serial number plate, makes it harder to work out which part of the manual changes is relevant for the unit.

David

[Gertjan]

Happy with my HP 8640B signal generator. Restoration is complete.


IMG_7919__HP_8640B_met_HP_5340A_550MHz-2000pix.jpg

After repairing the wipers on the A1S1 rotary switch, I also had to do the same on the A9 rotary switches. But the A9 module looked daunting to take apart:


IMG_7900__8640B_A9_with_original_gears-2000pix.jpg

However, the service manual has an excellent A9 assembly removal and disassembly procedure. Following the steps, and taking photo's all went well.


IMG_7823__8640B_A9,_A9A1_S1_and_S2_switch_rotor_positions_CCW-2000pix.jpg


IMG_7828__8640B_A9,_A9A1_S1_and_S2_switch_rotors_repaired-2000pix.jpg


Now the 8640B was fully functional again.

But I was not happy with the small cracks in the gears. It worked fine for now, but for how long?
I found small, 5mm wide open hose clamps:  Mikalor Open drive clip W2

I figured that if I clamp the gear, it will not crack any further. I used this clamp for the gears on the oscillator cavity:


IMG_7861__8640B_A3_cavity_oscillator_gears_repaired-2000pix.jpg

Unfortunately, on the gear to the right, the hose clamp did not fit, the part with the screw was too high. So there I used another solution, clamping with iron wire.

Now the only thing left were the A9 module gears. I think the hose clamp will also work for the A9MP9 spur gear, but not for the A9MP12 and A9MP13 combination gears, with their 45° tooth angle.
I choose the easy way out, and ordered the brass gears from India. The seller was helpful, and the gears are very well made:


IMG_7897__8640B_new_A9_gears_from_India-2000pix.jpg

I had the A9 module apart before, for repairing the rotary switches with new wipers. So taking it apart again was now routine, and installing the gears was a breeze:


IMG_7908__8640B_A9_with_new_gears-2000pix.jpg

I did a spot check on the electrolytics on one board (A11 modulation oscillator), and found them all in spec (Alu and Tant, Sprague and Kemet, 30D, 150D and T110). So I am confident that the rest will be OK too. After 50 years!

With everything in good working order, I went through the 50 pages of the performance check. I found everything in spec, as far as my test equipment (SA’s) was not the limiting factor.
I did find a bit of variation in output level at the highest frequencies. And traced it to cracked solder on the semi-hardlines in the A26 RF output module:


IMG_7835__8640B_A26_RF_amp,_cracked_RF_connector-2000pix.jpg

And indeed, re-soldering solved the problem.

Regards, Gertjan.

[nonius_]

Have read your contribution with much interest. Been reading up on the HP8640B for the past few days, as with a bit of luck I may soon become the owner of one myself. Have been longing for one for decades. Keeping my fingers crossed.

Had already read about the availability of replacement brass gears. Will be one of the first things I'll do with mine: check condition of the plastic gears, and, if needed, replace. To me, an apparatus like this would definitely be worth the cost of brass gears.

Are you familiar with this tool, a baling wire hose clamp? It could come in handy for making clamps for those broken gears. I've made several variants of this tool and find it incredibly useful on occasion:



Or an even simpler version:

 

It should be possible to cobble together a tiny version of this that would be perfect for those small gears. The result are very small, strong and neat-looking self-locking clamps using nothing but a piece of wire. (I've also made the much simpler and smaller variant as in the 2nd youtube-short, but can't find it at the moment....)

[Gertjan]

Hi nonius_,

I did not know about the "baling wire hose clamp". It looks very useful for the purpose of clamping the 8640B gears. Thanks for the tip!

If you are looking for a 8640B because you like to restore classic HP gear, and enjoy having iconic pieces of Test Equipment, I can recommend buying an 8640B

But if you are looking for a daily driver signal generator, look further. The 8640B was exceptional in it's time, and it's name is still legendary.
Also it is now 50 years old.... Later generations signal generators have improved a lot in many ways, and are not more expensive at radio rallies etc.

regards, Gertjan.

[I-Like-BWRs]

Just say NO to TEA.

Its just a small step from TEA to SPEED (Systematic Preservation of Endangered Electronic Devices). SPEED destroys lives!

 

I fail from this. I have an old PM3055 that I baby, and a HP 8510p that I refuse to get rid off *ever*. 13yrs old is only the start.... by the time im 30 I'll need a separate shed. I suffer from a case of ETEAS (Electronics Test  Equipment Addiction Syndrome)   

Ignore my makeshift probe - I still need to get a set.

[Zoli]

...
Are you familiar with this tool, a baling wire hose clamp? It could come in handy for making clamps for those broken gears. I've made several variants of this tool and find it incredibly useful on occasion:
...

Some time ago I've made a post about the safety wire twisting pliers; that would be my first choice for securing the cracked gears, but is always good to know/have more options.

[dazz1]

Just say NO to TEA.

Its just a small step from TEA to SPEED (Systematic Preservation of Endangered Electronic Devices). SPEED destroys lives!

 

I fail from this. I have an old PM3055 that I baby, and a HP 8510p that I refuse to get rid off *ever*. 13yrs old is only the start.... by the time im 30 I'll need a separate shed. I suffer from a case of ETEAS (Electronics Test  Equipment Addiction Syndrome)   

Ignore my makeshift probe - I still need to get a set.

I have the 100MHz version.   I like it.
I did an LED conversion on the graticule and the LCD.  Makes it nicer to use.
I wrote it up here on eevBlog Forum.

[nonius_]

[Zoli] Some time ago I've made a post about the safety wire twisting pliers;

Yes, I used those too back when I was still flying and a glider technician. A tool that's on the wish list, but haven't bumped in to one so far. Still have got plenty of stainless steel locking wire for it though. I use locking wire often when I want to be certain things don't come loose, using the proper techniques/procedures.

[Dazz1] I have the 100MHz version.   I like it.

Have the PM3055 as well, just as I-like-BWRs. (BTW, not a fan of PWRs?) It's an ok scope (keep in mind that there are some common problems with it, many having to do with the electrolytic caps; they're getting a bit old and mine is now on its 3rd set of caps, mostly in the SMPS) but it's the user interface I hate with a vengeance - it's just so different from what I'm used to. Can't get used to it.
But if you're young and it's your only scope, you'll probably be fine with it. I'm an old dog. You can still teach me new tricks but these days it takes a lot more dog treats

[dazz1]

[Dazz1] I have the 100MHz version.   I like it.

Have the PM3055 as well, just as I-like-BWRs. (BTW, not a fan of PWRs?) It's an ok scope (keep in mind that there are some common problems with it, many having to do with the electrolytic caps; they're getting a bit old and mine is now on its 3rd set of caps, mostly in the SMPS) but it's the user interface I hate with a vengeance - it's just so different from what I'm used to. Can't get used to it.
But if you're young and it's your only scope, you'll probably be fine with it. I'm an old dog. You can still teach me new tricks but these days it takes a lot more dog treats

The UI is not the best feature of the PM3070.  I prefer knobs to push buttons.  It is still an easy scope to operate.   I have recently acquired a Fluke PM3394A 100MHz, 4ch, digital and analogue scope in one but it has a fault.   That has a nicer UI.

[I-Like-BWRs]

Yeah.... myn had failing caps that I replaced, the infamous smoky Rifa mains cap. I only did the PSU, but I know I will have to finish it and do the rest of the scope soon. The NTC is on its last legs, corroded and out of spec. I think it fine. The LCD is nice to just glance at to know your settings, and the fancy autoset feature is nice as well as you can trick it to doing the 10x probe math's by shorting the little sense pin to GND (then again 10x something by ten isn't hard.

Boiling Water Reactors are just better. Steam boils in core so you get the delicious radioactive flavours from the core in the turbine. 
But anyway I like them because they are simpler, and basically when they say "a nuclear reactor is like a giant keetle" a BWR is a very good demo. Or maybe PWRs are too efficient ...
Where is ILikeCANDUs, or ILikeAGRs?

The PM3335 CombiScopes are cool. It fixing one of the main problems with CROs - single shot is really single shot. I find the UI fine, but I can see how if you are used to the normal layout it could be a pain.

[nonius_]

I forgot about the glorious RIFA, but in the PM3055's defence, you find that problem in many aging T&M-devices. Or general consumer equipment. I still have a mark on the wall where the paper filtercapacitor of a HP54504a launched its guts at high velocity....

Another problem with the PM3055 (and its brethren of the same series/age, also including bench multimeters such as the PM2525 and PM2535) is the plastic becoming brittle. And sometimes problems develop with the LCD's (my PM3055 is a Frankenstein, consisting of an old, brown front but a newer, white sub-panel, with new LCD's). Because of its unusual user-interface, I've relegated it to the role of 'permanent visual indicator' of the PM5193 function generator. With a press of the green button ('autoset') it adjusts itself perfectly, so no need for me to fiddle around with all those tiny buttons and their even tinier print.

But if I were young, had good eyes and wasn't so set in my ways w.r.t. 'conventional' scope layouts, then there'd be absolutely nothing wrong with the PM3055. Hopefully you'll get a lot of good use out of it!

[factory]

Plenty of my co-workers didn't have a problem with the Philips PM3055 user interface, they preferred it (and the horrid Fluke 123 thing) because of the auto button, they weren't interested in understanding how to drive a scope, analog or digital with the manual controls.
The 3055 at work had a problem for as long as I remember (it wasn't new when I started there), to start it required the "power on, off, on, off, on, off, on.... etc" procedure, eventually after a few years the inevitable happened, the PSU blew up.  , all ancient history now as it went in the bin with the rest of the lab (except for a couple of the knobs which escaped ).



Mine needs the PSU re-capicide doing, along with a replacement intensity control, which I did buy a NOS pot to replace.
I forgot how light that scope is, seen it for the first time in a while at the storage unit, which I'm currently in progress of moving several Tonnes of TE to a bigger one, it took Friday afternoon & all day Saturday to move everything in the first two pictures to a unit in a different building, nice to have some decent lighting for a change too.
Still got the heaviest boat anchors to move, HP aka Hernia Producer, the 524B is somewhere above 50kg, the 150A not too far behind, probably should take some tools down one day and transfer one of the replacement sides to the 175A at the bottom of the stack.

The missing 525B has also been located, I wanted to find out if they used paper capacitors in the turret mechanism, this was back when I was working on the 512B, which is this frequency converter module built into a small case with power supply, for use with the 524A and any other counter with a 100kHz reference output.



David

[Vince]

Wow that's like.... Carlson's lab league .. 
... and we know there is even more than that, that we can't even see in the picture....
Would be cool, once the move is finished, to have exhaustive pics of the entire collection, so we can get the full understanding of just how bad good it is ! 

[TERRA Operative]

A new version of my TDS Toolkit just dropped! Lots of additions, enhancements and fixes.

If you have a TDS500/600/700 series scope, check it and let me know what you think.

https://www.eevblog.com/forum/testgear/tektronix-tds500600700-pc-software-take-control-of-your-scope!/

[factory]

Wow that's like.... Carlson's lab league .. 
... and we know there is even more than that, that we can't even see in the picture....
Would be cool, once the move is finished, to have exhaustive pics of the entire collection, so we can get the full understanding of just how bad good it is ! 

That is something I should do, years ago I did attempt taking pictures the TE stacks in the previous unit, the lack of lighting made for some crap pictures, I gave up after that.

Some more was moved this afternoon, the two flimsy blue shelves & contents, a third of the contents from the big shelves and the stack of boat anchors in the corner, that was a big mistake putting them in that corner, this made it very difficult to access them, the 524B and two of my 175As are now in the correct place in the new unit, right by the door, the one on top was the first oscilloscope I bought, it got rather trashed in the post back in 2008, the sides got swapped with the one underneath, which I now have another pair of sides for.

The last of my stored TE will be moved on Friday afternoon (weather dependant), then begins the reorganisation, as it's quite a mess at the moment, the priority is vacating the old unit & stop paying for it.
The stacks on the floor had wood blocks under them, this will be put back during sorting, it's there in case the drains ever block and the floor floods, this did happen in my Dads workshop not too long ago, only thing directly on the floor was a box of cables & probes, took me ages to clean them all afterwards.

There is some more at home that will be moved in the future, including recent feeBay acquisitions and a van load I acquired from Woodchips, I went over a few weeks ago to acquire a Tek 577 & a BWD Powerscope, some Farnell DMMs, a V-F Instruments DVM and came back with lots more.
Edit: a few items from the van load already made to the store.

David

[Vince]

Oh, a Tek 577 curve tracer ! Didn't remember you had that one ! 

Hmmm.... top right corner of the second pic, the side of two similar looking boat anchors stacked on top of each other, I think I recognize those !! 

Oh, and a Tek TDS 300/400 scope in the van, I am surprised that you fell for such modern stuff !  Not your kind
No that's right... you do have some modern scopes.... your Yokogawa springs to mind now I think of it...

Now you need half a dozen heavy duty shelves to make all these instruments easy to access... but beefy shelves cost a mega fortune, at least here they do 
Only hope would be to search for used ones locally.

[doctormord]

Cheers,

i don't know if this is the right thread but got my hand on some PM5139 (Philips) generators where 1 was dead but hat V1.5 firmware and 3 others running V1.3. At first i just wanted to clone the V1.5 to the other devices but it escalated quickly.

I now have a nearly fully disassembled firmware (all documented) with the possibility to run own code from EPROM after the original firmware. To start i decided to run DOOM level 1 music. 

The GIT is here, i'll upload all the code and documentation in the next hours:

https://github.com/doctormord/Philips-PM-5139-5138A-5136-Firmware-Project

EEVBlog Link for the original firmware is here:

https://www.eevblog.com/forum/testgear/philips-fluke-pm5139-firmware-v1-3-v1-5-hex/


Proof:

https://youtube.com/shorts/Z7uDr8r39vI

[TERRA Operative]

Playing around with making apps for the TDS scopes. Getting an RS-232 decoder working at the moment. So far it's working as a proof of concept, if it's slow as a wet week..... 

[Vince]

Wow, didn't know the user could write applications for these scopes, how marvellous...
I didn't know Tek made a s/W development kit available... or did you / someone manage to get hold of it by some obscure channel ?! 

But the most remarkable isn't even the app... the most remarkable is what happened to Terra for him to become so confident and enthusiastic about writing code !
I mean if feels like yesterday when you wrote "My programming language is my soldering iron ! " . Or does my memory play tricks on me ?! 

What a sharp and sudden change ! For the better of course, as we get to enjoy / benefit from the fruits of your work ! 

I say keep going in this direction, it brings a lot of good ! 

[TERRA Operative]

Claude is doing all the hard work!

I still program with solder, but I also program with AI prompts now too... hahahaha, it's really opened up a lot of cool stuff that I've been wanting to do for a long time.

[Vince]

Oy !

It's not often, but new capabilities have been added to the lab... two of them :

1) Robert's current clamp addiction finally rubbed off on me, I bought my first clamp... tons of them out there of course, but I stumbled upon this one on leboncoin.fr  and its uncommon looks instantly rang a bell. Unless I am mistaken, I remembered Robert buying a few of them, saying it was a nice one that people overlooked constantly. So, he could get them for cheap. I think he said a nice feature is that they can do DC as well as AC which is not common for cheap clamps ? Anyway, it cost only 40 Euros, in good nick and working.




- Can do AC and DC then
- It's true RMS (up to 1kHz)
- Up to 200 amps
- Can measure voltage as well, and frequency, and VA and kW power, and Cos Phi as well.
- Has an analogue output so you can display the current measurements on a scope or plotter or whatever you fancy.
- Every time you turn it on, it calibrates itself for a few seconds, because it likes you and wants to offer you the best possible reading 

I am glad I found the user manual on-line because its operation is absolutely not intuitive. There is a big red "ON" button as you can see, and you have to operate this button in all sorts of ways to get the clamp to do this or that...


2) Second item is a nice score I think !

A friend works as a maintenance / field Tech for a telecom company ("Orange", the ex national French telco that got privatised and renamed this way).
They scrap lots of equipment and electronic boards all the time. Sometimes he brings me a little something. A few days ago he brought me a fancy TE... a TDR / Time-Domain Reflectometer.   It's a Megger TDR2000/2R.  Came with its carry case.  Large colour LCD, opto-isolated RS-232 at the rear.
At the back of it there is a nice table giving you an idea of the velocity factor for various types of cables.




He didn't tell me what was wrong with it.
The charger is missing, bummer, especially since it uses a weird 3 pin round connector... good luck finding that. I guess I can always replace it with a more standard connector...

It does not power up. In the battery compartment there is a weird battery pack : comes with a 9V battery connector ?!
Label on it says NiMH 9.6V 1.5Ah.   




It measured 2V or so...   I hooked it to my lab power supply, it appears to take a charge, so it's not dead / open-circuit, good.
I left it charging at 10% capacity as indicated on the label, for 5 minutes maybe. No luck, still doesn't power up, not even a blip.
Maybe I need to charge it some more...

No time for that, so instead I just cracked the thing open....



...unplugged the battery connector from the circuit board and hooked the lab supply, set to 9.6V, straight to the board...  It powers up !      ... but the display is sick, tons of vertical lines... 





... Quick check, found that the display connector was slightly mis-seated if that's a word. I reseated it... display works perfectly now !



Keyboard appears to be working, the instrument appears to be responsive... it's a winner !!! 


I had a quick look, looks like this thing costs 5K Euros or so ?!
A nice addition to the lab for sure ! 

Oh, I see that by some miracle, this weirdass battery pack is actually available NEW ! About 30 Euros shipped... tempting !
Will try to revive the original battery first, in case it can recover.
Then I need to test it, see if it can do what it's supposed to do...
Then see if I can find a charger for it... or just add two 4mm posts and recharge it with the power supply