Test Equipment Anonymous (TEA) group therapy thread

[m k]

There are things, it's what is acceptable.

https://www.intertronics.co.uk/product/professional-pcb-repair-kit/

factory's upper example picture is pretty clear, after cleaning bad parts away there are no place for anything mild.
It's also multilayer board so just surface is not enough.

I was once doing those commercially to things that were burned by the definition.
There is obviously a point where time is against money, but electrically solid was always first, if not possible then scrap.
Finally the style changed to do it, end of life situation where board supporting the component was not required anymore.
There it was opposite to the picture, single layer pad and track were there but board was missing or carbonized.

Lower picture is different, there mild surface operation seems to be the way, but there is a catch, track width and its volume.
Other thing is that a new surface pad must be connected permanently without solder.
It's again what is acceptable, component leg connects the other side and extra wire to component leg this side.
Leg being black is another issue.

Link's edge connector repair was not allowed back then, period.
It is not reliable enough.

[factory]

I did mention "Cir-Kit" which is the same type of trace repair kit from Pace, we had an old incomplete kit of this at work, not sure any of the UK suppliers had bits for it at the time anyway. Seems to requires eyelet rivets for through hole stuff as well. Never got to try this method. Probably never will looking at the cost.

https://paceworldwide.com/product-catalog/circuitry-repair-kits

I've repaired many burnt PCBs at work (up to 4 layer), often scrap is not an option, due to old kit that is very custom to trains and often the company that made it no longer exists, or they are not interested in providing technical info, or threw it away as it hadn't been used in the last 6 months.

Lower picture is different, there mild surface operation seems to be the way, but there is a catch, track width and its volume.
Other thing is that a new surface pad must be connected permanently without solder.
It's again what is acceptable, component leg connects the other side and extra wire to component leg this side.
Leg being black is another issue.

This was from a Tek 422 PSU with internal battery option, the screw next to the damaged trace holds a toroidal transformer on the back, not easy to get the back without removing half the wiring. I took the work from the top option, to avoid errors or damage to the transformer wiring, more pictures in the linked post. Capacitor leg going through seal is either tantalum or silver based? These are the materials that resist corrosion from the acid electrolyte, used in wet tantalum capacitors.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4098919/?topicseen#msg4098919

David

[TERRA Operative]

What about a replacement PCB from china?

I'm sure you could find one to make a PCB in phenolic etc.

[Vince]

That TERRA  chappy is one hell of a funny guy....

[m k]

Side of soldering shouldn't make any difference, tin will be sucked in equally both ways.

My case was a bit different than those above.
What I did went to the pile, and just a single partnumber for all.
So it was supposed to last like a new.
No idea how they were priced but some color codes were possible, general impression was also the it was punitive for non service agreement customers.

Finally you can make it electrically solid, pretty much always, if you give up enough of other ends.
Like heat may be a bit less, vibration also.

One good example is a cargo ship multiple ballast tank balancing system.
Memory was needed more than was available in RAM or few floppies so hard disk was used, that is the original changeable hard disk, 20" if memory serves.
The device was RL01/02 and everything was fine, until it wasn't, new 5 1/4" winchester couldn't do it, it crashed.
So the old drive had to be supported longer than was the intention, luckily it actually wasn't very niche product.

In case of interest of early day's hard disks, IBM RAMACs have something to show.
(maybe a random viewer is a bean counter)

[m k]

That TERA  chappy is one hell of a funny guy....

Inspiring surroundings, I guess.

[factory]

Is there anyone on here that has a HP 5221A or 5321A, with a factory fitted 50Hz timebase option (labelled as 010, 110, or 210)?
I'm currently working on a US 60Hz version, to convert it to run the timebase from 50Hz and part of the modification is to add a capacitor A2C12 between XA2(1) & XA2(8 ).
But I've noticed conveniently placed holes between 1 & 11 on the A2 board and I'm questioning why, is there a mistake in the manual, or some other reason for these holes?

Hopefully someone can help.

David

[vk6zgo]

I did mention "Cir-Kit" which is the same type of trace repair kit from Pace, we had an old incomplete kit of this at work, not sure any of the UK suppliers had bits for it at the time anyway. Seems to requires eyelet rivets for through hole stuff as well. Never got to try this method. Probably never will looking at the cost.

https://paceworldwide.com/product-catalog/circuitry-repair-kits

I've repaired many burnt PCBs at work (up to 4 layer), often scrap is not an option, due to old kit that is very custom to trains and often the company that made it no longer exists, or they are not interested in providing technical info, or threw it away as it hadn't been used in the last 6 months.

Lower picture is different, there mild surface operation seems to be the way, but there is a catch, track width and its volume.
Other thing is that a new surface pad must be connected permanently without solder.
It's again what is acceptable, component leg connects the other side and extra wire to component leg this side.
Leg being black is another issue.

This was from a Tek 422 PSU with internal battery option, the screw next to the damaged trace holds a toroidal transformer on the back, not easy to get the back without removing half the wiring. I took the work from the top option, to avoid errors or damage to the transformer wiring, more pictures in the linked post. Capacitor leg going through seal is either tantalum or silver based? These are the materials that resist corrosion from the acid electrolyte, used in wet tantalum capacitors.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4098919/?topicseen#msg4098919

David

When I was at the TV studio job, I used the Cirkit kits a lot.
 
I found that the best way to secure the replacement tracks was to go for one with a slightly larger hole than the eyelet required, & use the latter to not just replace the "Plated through" hole material, but also to secure the track at the hole end.
Usually, I could overlap the track enough at the other end to make a very secure solder joint.

Usually, the priority was that they needed the equipment "yesterday", so "as solid as possible, but don't go overboard" was the rule!
From time to time, you need larger eyelets, which are hard to come by.
mnementh in "another place" (not the Senate) found some small rivets for another purpose very cheaply, which did an excellent job in just such an "edge case".

[m k]

Is there anyone on here that has a HP 5221A or 5321A, with a factory fitted 50Hz timebase option (labelled as 010, 110, or 210)?
I'm currently working on a US 60Hz version, to convert it to run the timebase from 50Hz and part of the modification is to add a capacitor A2C12 between XA2(1) & XA2(8 ).
But I've noticed conveniently placed holes between 1 & 11 on the A2 board and I'm questioning why, is there a mistake in the manual, or some other reason for these holes?

Hopefully someone can help.

David

Based on a manual I found,
78 pages with Errata cover by Agilent.
5221A / 5321A Electronic Counters Operating and Service Manual
05221-90001
July 1971

That is not exactly very clean scan.
I'd say that pin 11 is the original position.

Service note page 75/78 has a noise reduction fix.
There 2k resistor is added between pins 8 and 11.
But before that pin 11 connection is moved to pin 8.

[Vince]

SCREW YOU !!!

Putting back the QUAD transistors into place. Small H/W problem...On of one of them, one of the two screws the hold the plate sitting between the PCB and the trannystor, snapped.
I could extract / remove the broken bit of the screqw from the plate, but now I need a replacement screw..... of course being an, old British amp... it uses imperial screws, so I am screwed.

I don't have taps to get the plate to accept the nearest metric size up (M3), and the size below is too skinny.
So the plan is to use M3 but not tap the plate, just drill it. So the screw won't be able to bite into the plate, but that's OK since we have a nut at the top of the assemly that secures the entire assembly anyway.

So, I need to find M3 screws in my scrw box, with the same shape/style of head and a similar patina (dull not bright ie)  so it doesn't look too out of place.

So I need to search my screw box..... but.... too many screws in there, searching is a vain exercise... so I need to first sort all of them... so it's 12H15 and my Sunday afternoon looks like it will be mostly about sorting small screws...  wish me luck !   I weighted the screws at 3,007 grams... 3kg of small screws is a lot of screws...

Of course I won't check the diameter and pitch of every one of them... I would need a full month full time.. But at least do a first pass to sort them into broad categories, to speed this, and future searches.

I also made a tragic mistake recently : when I took that Kay RF boat anchor apart the other day, I salvaged a tons of nice screws and some nuts... and stupidly put them with other screws.. which are metric of course.    Luckily sort of remember what these screws looked like, rough size, and also remember they were all lovely stainless steel.... so I could use a magnet to find them... well, I mean, eliminate those that can't be them that is.

Anyway. I prepared a dozen bins/drawers to do the first pass. The this winter when it's cold dark and windy and rainy... and  am bored.. I can grab these drawers one by one and further sort them into finer categories...

Yes, I could go to the H/W store tomorrow after work and buy some M3 bolts... but it's not fun and it's money.
I could also buy imperial bolts at great cost.. no. I have already spent plenty enough money restoring these QUAD amps, enough is enough...

So I thought it would be a good excuse/pretext to get off my butt and finally start sorting these screws... eh ?

That is all, sorry for the trouble...

[m k]

Listen to the pouring rain

[xrunner]

So I need to search my screw box..... but.... too many screws in there, searching is a vain exercise... so I need to first sort all of them... so it's 12H15 and my Sunday afternoon looks like it will be mostly about sorting small screws...  wish me luck !   I weighted the screws at 3,007 grams... 3kg of small screws is a lot of screws...

Yes and you remember I got fed up with my jumble of screws and spent a week sorting it all out. It was well worth it in the end and now I can find anything I need easily and quickly. 

[tautech]

Machine screws from self tappers would be a good start. 

[Swainster]

Old machine screws of that size in British equipment might actually be BA screws. I believe that they are a kind of metric thread, which actually predates the modern metric thread system... and naturally is totally incompatible.

On an aside, I have an old car which has British Standard fasteners, except for the engine, which has metric fasteners with British Standard head sizes... so you only need one set of spanners. However, if you don't realise this then woebetide if you get any of the engine fasteners mixed up with any other fasteners on the car... such as, say, the gearbox

[factory]

Is there anyone on here that has a HP 5221A or 5321A, with a factory fitted 50Hz timebase option (labelled as 010, 110, or 210)?
I'm currently working on a US 60Hz version, to convert it to run the timebase from 50Hz and part of the modification is to add a capacitor A2C12 between XA2(1) & XA2(8 ).
But I've noticed conveniently placed holes between 1 & 11 on the A2 board and I'm questioning why, is there a mistake in the manual, or some other reason for these holes?

Hopefully someone can help.

David

Based on a manual I found,
78 pages with Errata cover by Agilent.
5221A / 5321A Electronic Counters Operating and Service Manual
05221-90001
July 1971

That is not exactly very clean scan.
I'd say that pin 11 is the original position.

Service note page 75/78 has a noise reduction fix.
There 2k resistor is added between pins 8 and 11.
But before that pin 11 connection is moved to pin 8.

Thank you that has helped  , seems they forgot to add that info to the back dating changes for older instruments.

Some pictures of what I have.



And digging out a real manual (05221-9011 s/n prefix 920) confirms everything, pin 8 doesn't even get a mention on the circuit diagram. The mod procedure gives pins 1 & 11 for A2C12.  Just noticed they forgot the "disconnect yellow wire".





The decade divider replacement board got wiring added yesterday, an extra connection was needed for grounding unused reset input, the 5221 board has no connection for this.



Original divide by 6 IC.



Pinout is slightly different for later DIL divider IC compared with the T099 divider IC.



David

[m k]

I searched back to your 5221 comment a year ago and couldn't see the option 003.
It's a very simple independent 100Hz oscillator board.
Only 6 contacts wide connector, power in and pulse out.

The bad scan manual from amazonaws has 003 as another service note, page 76/78.
Page 68/78 is the 1st part of A2, left under a connector picture is a note for 003.
Schematics pin 11 color is missing, so no wire.
But pin P has triple color wire, extra C3 is also a bit disoriented.
Seems that the addendum maker wasn't very nitpicky.
Must hope somebody else made those service notes.

I also tried what the great order of pictured information has to say about the option 003.
Not much.

Then that mini stand, what is its name?
I tried all and then some but couldn't get even close, must be something completely different.
Those general slit stands I once had few, but they were self made from coated plywood, it was one of those something here right now situations.

[Vince]

Old machine screws of that size in British equipment might actually be BA screws. I believe that they are a kind of metric thread, which actually predates the modern metric thread system... and naturally is totally incompatible.

On an aside, I have an old car which has British Standard fasteners, except for the engine, which has metric fasteners with British Standard head sizes... so you only need one set of spanners. However, if you don't realise this then woebetide if you get any of the engine fasteners mixed up with any other fasteners on the car... such as, say, the gearbox

Well that's interestingly odd... funny how everything possible exists under the sun... I do like old British cars but luckily my favorite one is not quite old enough to suffer from such disastrous inventions.
IIRC she is 100% metric.

Yes and you remember I got fed up with my jumble of screws and spent a week sorting it all out. It was well worth it in the end and now I can find anything I need easily and quickly. 

Of course I remember !    However I didn't remember it took you that long ! 
In my distant memory I thought you did it over a week-end.

It's 19H00..... I have just finished, so it took me 6H30 to do...

Of course it's just a first pass, needs a second pass, but I am delighted with the result... at least now I do stand a chance of finding stuff in there.

I ended up with 15 bins in total :

- The outsiders : screws that looked too weird to be categorized at all, so I put them all in one bin... if I need something strange, that's where I would look.

Then I sorted the machine screws and self tappers.

Machine Screws :

- BTR
- Bigger ones
- "Computer" screws
- Those with captive whasers, or a head that's shaped like it's got an "integrated" washer... thin large and pan cake like...
- Slotted  flat heads : so that I don't waste time finding them when I need one for my vintage gear
- Counter sunk heads
- Hex heads
- Everything else

Self Tappers

- Counter sunk
- Head with captive washer or integrated washer head design
- Black ones
- Silver ones
- Yellow ones
- Funky colour ones : I got a few red and a few blue.


Now I need a second pass to sort the really small ones from the rest, at least.
I noticed there are several types of thread for the self tappers, might need to sort them.


Anyway, such a pleasure already to look at those bins...

Now I need sort the nuts&washers tray 

[bsdphk]

This is one of the big failures of the "maker-movement":

We have cheap USB cameras and microscopes, we have more stepper motors and mechatronics than we know what to do with...

But where is the machine you pour your "misc screws" container into, and have the come out neatly sorted after your criteria of choice?

It doesn't even look like anybody has seriously tried..

[TERRA Operative]

Anyone have any cheap tricks (i.e. one chip solutions etc) to get dual rail voltages from a +5V supply? I'm looking for at least -20VDC and +25VDC to power an opamp, current draw is in the mA range (LCD bias, yep still working on the THS700 displays) I can probably measure current draw if needed.

I need something simple and compact (!!!). I'm sure there's something out there... I just need to be pointed in the correct direction..

[themadhippy]

But where is the machine you pour your "misc screws" container into, and have the come out neatly sorted after your criteria of choice?

you could adapt my bodged coin sorter,just a box with  a bit of wood half way down with suitable sized  holes in it,fill with assorted screws,velcro it onto your vibrating bed (electric sander) and let it run for 5 minutes.

[xrunner]

Yes and you remember I got fed up with my jumble of screws and spent a week sorting it all out. It was well worth it in the end and now I can find anything I need easily and quickly. 

Of course I remember !    However I didn't remember it took you that long ! 
In my distant memory I thought you did it over a week-end.

No way just a weekend - it took me a week because of the jumble of screws hoarded over years. Metric and SAE all mixed up.

Then I had my helper of course ... 

[Neomys Sapiens]

Anyone have any cheap tricks (i.e. one chip solutions etc) to get dual rail voltages from a +5V supply? I'm looking for at least -20VDC and +25VDC to power an opamp, current draw is in the mA range (LCD bias, yep still working on the THS700 displays) I can probably measure current draw if needed.

I need something simple and compact (!!!). I'm sure there's something out there... I just need to be pointed in the correct direction..

What about those 1W SIL DC/DC converters, like those from Recom, Murata (formerly Newport), countless others...
They are available with +/-24V outputs from a 5V input and less hassle isn't possible.

[wkb]

This is one of the big failures of the "maker-movement":

We have cheap USB cameras and microscopes, we have more stepper motors and mechatronics than we know what to do with...

But where is the machine you pour your "misc screws" container into, and have the come out neatly sorted after your criteria of choice?

It doesn't even look like anybody has seriously tried..

SMOM: just use non-magnetic stainless steel for metric, and steel for UNC and what have you.
Small Matter Of Magnet to sort them..

Wilko

[Vince]

OK I got carried away, I gave my nuts&washers drawer a quick first pass, now almost 22H30 so I call it a productive Sunday.

- Nuts - small
- Nuts - small but a size up. Well, my highly technical definition of "size" = oh, that one looks a bit larger than the other ones, let's put it in that bin instead..."
- Lock nuts
- Captive nuts
- Nuts - large ones for panel mount controls, pots and switches etc
- Lock washers : large ones for panel mount controls.
- Lock washers : split type
- Lock washer : all other types, I don't know how they are called.
- Flat washers


I have run out of plastic dividers to organize the drawers, annoying... the 4 cabinets I bought last year to sort my components and stuff, didn't come with that many dividers, they cheaped out    Luckily they were rebadged RAACO units, so I can buy standard RAACO dividers which I think can be bought separately on the interweb. So I will buy a bunch of them.

[factory]

I searched back to your 5221 comment a year ago and couldn't see the option 003.
It's a very simple independent 100Hz oscillator board.
Only 6 contacts wide connector, power in and pulse out.

The bad scan manual from amazonaws has 003 as another service note, page 76/78.
Page 68/78 is the 1st part of A2, left under a connector picture is a note for 003.
Schematics pin 11 color is missing, so no wire.
But pin P has triple color wire, extra C3 is also a bit disoriented.
Seems that the addendum maker wasn't very nitpicky.
Must hope somebody else made those service notes.

I also tried what the great order of pictured information has to say about the option 003.
Not much.

Then that mini stand, what is its name?
I tried all and then some but couldn't get even close, must be something completely different.
Those general slit stands I once had few, but they were self made from coated plywood, it was one of those something here right now situations.

Before I asked about the 50Hz version last night, I had a search of the web of 5221A & 5321A, but couldn't find pictures of the 50Hz version.

I did however find some of the 003 crystal timebase option.
There is quite a bit more to add for that, two aluminium brackets, an edge connector & associated wiring loom and the crystal timebase PCB.



I've no interest in recreating this as I have the 5321B version too, still not got round to testing that one as I need to build a bucking transformer for it's oddball mains voltage requirements (special version).

Mini stand is actually a mounting pad (see page 7 of linked pdf) for those 8 pin TO package ICs & trannystor arrays, it got used to help form the wiring of the DIL adaptor board into the round pattern, to fit the counter board in place of the TO99 IC.
https://www.mecint.co.uk/sitedocuments/1322062180transistormountingpaddata.pdf



Also available are square mounts to convert round TO to DIL, those all disappeared before I rescued the components. https://www.farnell.com/datasheets/51739.pdf
https://uk.farnell.com/fischer-elektronik/us-58-4/transistor-pad-to-5/dp/1619035?st=mounting%20pad



The divide by 10 IC adaptor board, has been fitted to the HP 5321A and tested with the existing 60Hz wiring & component setup, 100 is now displayed in check mode instead of 60. 



Then the component & wiring modifications were done for option 010 (50Hz timebase), just run out of time to test it.





David