Test Equipment Anonymous (TEA) group therapy thread

[Cubdriver]

The new driver IC cured the missing 'a' segment issue in the MSD of the 432C, but it's also looking like I may need to replace the one for the LSD, too - circuit for the bottom segment 'd' appears to be leaky, too, as it stays partially on when it shouldn't be.  Looks like I'll be doing more surgery on the display unit.


The other issue I noticed is related to the panaplex display itself - the instrument must have spent a LOT of time either in autorange with no signal present, or on one of the 10X ranges as the glass in front of that decimal point is heavily sputtered and opaque (note the silvered spot roughly in the center of the picture at the corner of the topmost full digit), and a fair bit though not as much time in the 100X range (DP at bottom corner of lower digit) - partially blocked by sputtering.  The 1X decimal point (top, adjacent to '1' digit) is nearly clear.  The slightly dim center section of the segment that was out before seems to have mostly recovered after I left the meter on all day yesterday giving it some burn-in time (note that it is considerably brighter and more evenly lit in the first picture in this post, which was taken last night after it had been on for about 12 hours)


1X decimal point lit:


10X decimal point lit (hidden behind silvered spot when viewed from the front):


That said, it /sort/ of agrees with my 437B given that I've done nothing yet beyond fixing the display section.




I found replacement SP-351 displays on our favorite wallet-sucking site and have them enroute, but may try to rig up some orange SMD LEDs on the display face for the decimal points first, rather than replacing the otherwise operational panaplex display.  Frustrating that it can be rendered inoperative by such a tiny fault.

-Pat

[bd139]

What are you talking about? My post was about a mod to a bench meter, and all the other discussion has been about visiting a hamfest... all very much on-topic. 
mnem
*SMH*

I think he's refereing to BD139's post above with the embedded video that has no relevance.
It's one thing to reply with a short fun quip, it's another to embed a video as clog up the page.

I shall add to my personal post moderation checklist.

Hums Auferstanden aus Ruinen

[bd139]

The new driver IC cured the missing 'a' segment issue in the MSD of the 432C, but it's also looking like I may need to replace the one for the LSD, too - circuit for the bottom segment 'd' appears to be leaky, too, as it stays partially on when it shouldn't be.  Looks like I'll be doing more surgery on the display unit.


The other issue I noticed is related to the panaplex display itself - the instrument must have spent a LOT of time either in autorange with no signal present, or on one of the 10X ranges as the glass in front of that decimal point is heavily sputtered and opaque (note the silvered spot roughly in the center of the picture at the corner of the topmost full digit), and a fair bit though not as much time in the 100X range (DP at bottom corner of lower digit) - partially blocked by sputtering.  The 1X decimal point (top, adjacent to '1' digit) is nearly clear.  The slightly dim center section of the segment that was out before seems to have mostly recovered after I left the meter on all day yesterday giving it some burn-in time (note that it is considerably brighter and more evenly lit in the first picture in this post, which was taken last night after it had been on for about 12 hours)


1X decimal point lit:


10X decimal point lit (hidden behind silvered spot when viewed from the front):


That said, it /sort/ of agrees with my 437B given that I've done nothing yet beyond fixing the display section.




I found replacement SP-351 displays on our favorite wallet-sucking site and have them enroute, but may try to rig up some orange SMD LEDs on the display face for the decimal points first, rather than replacing the otherwise operational panaplex display.  Frustrating that it can be rendered inoperative by such a tiny fault.

-Pat

Worth looking out for Heathkit clocks and calculators. They are probably cheaper sources if you don’t mind a gamble. I was never a fan of panaplex displays. All the reliability of light bulbs multiplied by the number of the segments in one inconveniently large package

[tggzzz]

What are you talking about? My post was about a mod to a bench meter, and all the other discussion has been about visiting a hamfest... all very much on-topic. 
mnem
*SMH*

I think he's refereing to BD139's post above with the embedded video that has no relevance.
It's one thing to reply with a short fun quip, it's another to embed a video as clog up the page.

The phrase "I think" is relevant. I'm too am completely unsure what gnif is referring to[1].

While a detailed explantion would be counterproductive, it would help to indicate in general what prompted the mod's comment, e.g. "discussing clothes" or "OT videos" or....

[1] special case: I dislike vids so much my browser doesn't display the static image unless I examine the DOM - which does happen but is rare

[BU508A]

Edit:
Someone replaced the display with an OLED one.
Project page: https://github.com/openscopeproject/HP34401a-OLED-FW

Tis' surely is a heinous crime!!

Why? Okay, the OLED being used is arguable but this is imo the poodles core:

"After acquiring one of such devices off ebay and encountering the leaking driver issue which lead to artifacts on the screen, a decision was made to rectify this situation. This project is result of many evenings of carefully reverse engineering the protocol between the CPU of the meter and it's front panel controller IC and designing a sniffing device that would extract the data sent to the front panel and display it on a more modern display instead."

With this and designing a driver pcb, one should be able to use a VFD instead, like one of those (NAWTS):

https://www.ebay.com/itm/304596654148

[bd139]

Honestly with the 34401A OLED thing I would definitely do it as well once the VFD supply dries up.

I actually thought through the process before the OLED project even existed. But I came with the overkill idea of replacing the entire front panel PCB instead of just the display. A single pre-manufactured drop in module would be a good product and cost effective compared to a display module of unknown heritage.

[Cubdriver]

Worth looking out for Heathkit clocks and calculators. They are probably cheaper sources if you don’t mind a gamble. I was never a fan of panaplex displays. All the reliability of light bulbs multiplied by the number of the segments in one inconveniently large package

LOL - they are something of a bitch to get into boards or sockets with their very thin, bendy, mess of pins that never seem to all be parallel to one another.

Good point re the Heathkit clocks - now that you mention it, I built one of them back 40+ years ago that had panaplex displays in it.  At some point over the years it must have been tossed as it’s long missing.  Hell, if I bought another I’d likely wind up restoring it for nostalgia's sake.

In this particular instrument's defense, the components in the readout assembly have 1978 date codes on them, so it is nearly 44 years old (it’s treated as a sub assembly and replaced as a unit, the instrument itself had 1972 date codes on its other parts so I doubt it’s the original meter assembly).  Lord only knows how many hours are on it and the display still works, unfortunately it seems they ran the decimal points too hard causing them to sputter onto the window.  If I do wind up replacing the display, I think I’ll put some more resistance in series with the DPs to drop the current a bit more.

Slowly but surely I’m making progress on this thing - it’s been in the queue for probably four years now.

-Pat

[Robert763]

Dumb question time. Where can I get black jacks that match the red on my 3456A? 

I can't help with that, but it prompted me to think about something I've had in mind for a while, which is to custom make myself some 4mm jacks. I've just about convinced myself to get one of those mini-lathes. Yes, they are crap, but they are also 100% better than no lathe at all and I keep on finding problems that could be solved in 10 minutes with a small lathe and a chunk of brass or machinable plastic, such jobs being well within the capabilities of those mini-lathes.

Which gets me to a question for the assembled multitude. Does anyone have any experience with using acetal (aka Delrin aka PoM/Polyoxymethylene) for jacks, insulators, standoffs and the like? The reason for picking on acetal is that it's really easy to machine, has good mechanical properties, and seems OK electrically (resistivity 14 x 10^15 ohm cm, better than polythene or PVC, on a par with nylon and polycarbonate, worse than kapton, FEP, and PTFE). It's not a material I've seen used commercially, but that may simply be because it's expensive compared to reasonably electrically comparable materials and it's good machining properties are not called for in normal manufacture - people usually cast these kind of parts, not turn or mill them.

Yes I've used Delrin in the day job for insulation and it works very well. Some of this was in high impedance and or low noise circuits. We used it in lots of other applications too. It is an excellent all round material. As the day jobs have been about quality and fairly low volumes we did not worry too much about the cost. I have also used it in RF / high voltage applications like HF antenna insulators. I have a small stock of off-cuts 

When looking at lathe suppliers I can highly recommend ARC Euro trade. Most of these are made to a basic design, quality and extras depend on what the customer (your suppplier) asks for.

[Specmaster]

What are you talking about? My post was about a mod to a bench meter, and all the other discussion has been about visiting a hamfest... all very much on-topic. 
mnem
*SMH*

I think he's refereing to BD139's post above with the embedded video that has no relevance.
It's one thing to reply with a short fun quip, it's another to embed a video as clog up the page.

The phrase "I think" is relevant. I'm too am completely unsure what gnif is referring to[1].

While a detailed explantion would be counterproductive, it would help to indicate in general what prompted the mod's comment, e.g. "discussing clothes" or "OT videos" or....

[1] special case: I dislike vids so much my browser doesn't display the static image unless I examine the DOM - which does happen but is rare

Surely it cannot be the short video in BD's post that brought gnif back into the thread to moderate, or as Dave suggested that it was clogging the page up? I understood that all that is stored on the page is the short URL, the video is still on YouTube's site. The same as when we use photo hosting sites in order to post hi-res pictures without taking up vast amounts of Dave's storage space 

So I can only conclude it was all the chatter about hamfests and what kit to pack to prepare for the ever-changing weather, which while not technically on topic, it is closely related seeing as that is where many of us actually acquire much of our test equipment from as fixer uppers. Or could it be that we have a whistle-blower in our midst who is attempting to mould the thread into their perceived view of what it should be like, despite the topic being discussed is clearly being participated in and enjoyed by many other members.  So with that in mind, if moderators really feel the need to keep stepping in and moderating, it would most helpful to everyone if they were to take a few extra seconds and explain their actions a little more.

As one of the members who have been on this thread almost from its birth, I'm really struggling just to see why it is that the moderators have even been involved in this thread as we have, IMO, self policed it very effectively and as such, it does not seem to be deterring new members joining at all and the number of daily posts is on the up all the time which is surely just what advertisers (sponsors) want to see as it maximizes their exposure to members.

[Zenith]

So I can only conclude it was all the chatter about hamfests and what kit to pack to prepare for the ever-changing weather, which while not technically on topic, it is closely related seeing as that is where many of us actually acquire much of our test equipment from as fixer uppers. Or could it be that we have a whistle-blower in our midst who is attempting to mould the thread into their perceived view of what it should be like, despite the topic being discussed is clearly being participated in and enjoyed by many other members.  So with that in mind, if moderators really feel the need to keep stepping in and moderating, it would most helpful to everyone if they were to take a few extra seconds and explain their actions a little more.

I suppose moderating has to be an intuitive process, where the mod has a feeling that things have gone too far at some stage. It can't be boiled down to simple rules, although some topics might be declared out of bounds.

I could understand why gnif stepped in a week or so back when there was a lot of talk of cats, driving
and speed limits, bonfires in France and so on.

I don't understand the latest intervention. Most of these off-topic, or barely on topic, things fizzle out pretty quickly on their own.

[BU508A]

Looks like, we are under covert monitoring:

[Specmaster]

<snip>

I don't understand the latest intervention. Most of these off-topic, or barely on topic, things fizzle out pretty quickly on their own.

Exactly this, IMO, all the off-topic chat that goes on here is what has been previously described as water cooler talk, the sort of chatter you get while standing at the bar ordering a round drinks. Someone has a comment that they think is of common interest to most people without being technical, ie. a social comment, and once out in the open, disappears into the ether unless someone deliberately stirs the pot and causes a melee.

[Robert763]

TEA arrival
I heard the big brown Truck (UPS, noisy big merc diesel)* pull up across the street and welcomed the driver at the door.
pic 1 A big Box,
pic 2 Packing seems OK
Pic 3 Packing very good actually
Pic 4 A Fluke 8845A 61/2 digit DMM Looks OK. The missing "Rear" button was well documented on the ebay listing. I'm highly unlikely to use the rear inputs anyway so not bothered.
Pic 5 It's alive. 
Basic checks are OK. VFD is not perfect with variation in brightness for some pixels. Again this was in the listing. Perfectly usable though. This picture was taken in full daylight with a window behind me.
Very happy so far. I'll have to read the manual to get full use of this meter with the analysis functions etc.

Anyone want a HPAK 34970A datalogger / DMM that this will replace on the bench?

[med6753]

If I expressed my true opinion of this latest moderator intervention I'd get banned for sure. I called it, and it's becoming true.

I think I just better shut up.

[factory]

The new driver IC cured the missing 'a' segment issue in the MSD of the 432C, but it's also looking like I may need to replace the one for the LSD, too - circuit for the bottom segment 'd' appears to be leaky, too, as it stays partially on when it shouldn't be.  Looks like I'll be doing more surgery on the display unit.


The other issue I noticed is related to the panaplex display itself - the instrument must have spent a LOT of time either in autorange with no signal present, or on one of the 10X ranges as the glass in front of that decimal point is heavily sputtered and opaque (note the silvered spot roughly in the center of the picture at the corner of the topmost full digit), and a fair bit though not as much time in the 100X range (DP at bottom corner of lower digit) - partially blocked by sputtering.  The 1X decimal point (top, adjacent to '1' digit) is nearly clear.  The slightly dim center section of the segment that was out before seems to have mostly recovered after I left the meter on all day yesterday giving it some burn-in time (note that it is considerably brighter and more evenly lit in the first picture in this post, which was taken last night after it had been on for about 12 hours)


1X decimal point lit:


10X decimal point lit (hidden behind silvered spot when viewed from the front):


That said, it /sort/ of agrees with my 437B given that I've done nothing yet beyond fixing the display section.




I found replacement SP-351 displays on our favorite wallet-sucking site and have them enroute, but may try to rig up some orange SMD LEDs on the display face for the decimal points first, rather than replacing the otherwise operational panaplex display.  Frustrating that it can be rendered inoperative by such a tiny fault.

-Pat

Worth looking out for Heathkit clocks and calculators. They are probably cheaper sources if you don’t mind a gamble. I was never a fan of panaplex displays. All the reliability of light bulbs multiplied by the number of the segments in one inconveniently large package

But do the Heathkit cloc-u-lators use the same size/height/type of display? Also Panaplex displays are used in some pinball machines in high quantities, probably in high demand there too. I'm sure "bigclive" shows the inside of one in a YT video, but it's probably OT and can't be posted here.

I never did add the pictures of mine, in a HP 432B (no auto ranging on 'B' model), it also has the same worn decimal point issue, but not so bad that it isn't visible. If it was replaced you would need to either transfer the over-range decal, or make a new one.





Also have a panel voltmeter that uses similar or the same displays. We had a very large cable crimp pull test machine at work with a similar panel meter, but it got scrapped without my knowledge, not that I could have rescued it anyway, due to the no you can't buy it policy ATM.  They are probably filling more skips, during the shutdown fortnight, as I post this. 

Here is my Data Tech panel DVM, almost looks unused in comparison to display in the HP 432B.







David

[Specmaster]

@factory

Why won't they allow you to purchase the items that they are effectively junking, it makes zero sense to me at all.

[bd139]

Had that at a couple of companies I worked for. Fairly normal. The company I work for at the moment shredded 15x new unused 16" i9 macbook pros a couple of months under the same guise 

Just been informed my transistor lot is out for delivery via Herpes. Hopefully they won't throw it on my roof or something 

[factory]

Current corporate policy, they won't tell me why, just they won't sell to employees ATM. Might be due to change of company name, or the previous guy that did the scrap orders left & the replacement hates everyone, your guess is as good as mine. 
I couldn't take all of the redundant kit anyway, as the scrap policy is for "personal use only", no selling/trading it on.

bd are you bidding on the second transistor lot?

David

[med6753]

@factory

Why won't they allow you to purchase the items that they are effectively junking, it makes zero sense to me at all.

It depends. IBM's "official" policy is that surplussed or written off equipment go to a scrap/surplus dealer. Unofficially depends on who you know. Several years ago I obtained a Tek 475A and 2430 directly and legitimately from my brother with the blessing and permission from his management. And I've worked with surplussing equipment myself in the past and know the entire process and how to get something properly "off the books". It was done for those 2 scopes. And going further back I bought a 2465 that had come directly from IBM and I knew by it's age that it's "net book value" would be zero.

[Zenith]

@factory

Why won't they allow you to purchase the items that they are effectively junking, it makes zero sense to me at all.

At one company I worked for they had auctions where surplus equipment was sold off to employees. They abandoned them because there were complaints from people on other sites that they hadn't had a sniff of it, and the accountants found it hard to get the proceeds into the company. I was told that what happened after then was that it was sent to another part of the company overseas to be disposed of, and it was off their hands.

The cost of this stuff is nothing in terms of the finances of the company, and they'd rather get rid of it and have no accounting problems and moaning over fairness.

[GreyWoolfe]

https://www.amazon.com/AltruPrint-5200-RK-AP-LaserJet-Transfer-Rollers/dp/B07D2VH4S8

This kit will fix 98% of the common wear problems with a 5200; everything in the HP Maintenance kit except the very expensive fuser. This kit is available all over in various forms, but these are the parts you will sooner or later need. Install those bits and clean the fuser roller with a cloth dipped in alcohol and she love you long time.

mnem
*toddles off to ded* 

Back in the day working on the Lexmark T600 series printers, we'd turn the grey rollers inside out and put them back on the hubs if we absolutely had to get the printer working again and not wait for parts.  Especially if the customer wasn't looking over my shoulder.  There were regular customers I told that to so the printer would continue to work while waiting on parts/service.  I used to have to service printers at a SYSCO distribution center.  They bought maintenance kits, including fusers and toner cartridges by the pallet, strictly OEM.  They had 6 printers lined up, maintenance cycle was 200K prints and I was there monthly to service all 6 at one time.  Those printers had millions of prints through them and simply chugged along happy as long as they got their regular maintenance.  Very rarely had a real service call and even more rarely actually couldn't fix it and had to get a replacement.

Always wanted a networked 5,000 with duplexer and Jet Direct card.  I still have a digitized service manual somewhere. Think I am going to cruise the Bay of Evil to see what is there.

EDIT: holy cow, have prices gotten dear.  Couldn't find a 5000 cheap, $280 USD including shipping for a parts unit.  Over $400 for a working one.  5200s even more expensive.  I think I will stick to my $200 Brother networked, duplexed laser printer for as long as I can.  Besides, our logistics guy sent me an HP LaserJet MFP-M477fnw NIB that was just laying around.  Very nice as a $750 device should be and the document scanner works fine in Linux.

[bd139]

bd are you bidding on the second transistor lot?

Yes and I have a lot of money to burn at the moment so will be bidding completely irresponsibly 

First lot due to be delivered today.

Edit: I'll do a full inventory once I've received both lots (assuming I win the second one) and have moved house. If anyone needs anything, let me know. No Ferengi tactics here

[BU508A]

bd are you bidding on the second transistor lot?

Yes and I have a lot of money to burn at the moment so will be bidding completely irresponsibly 

First lot due to be delivered today.

Edit: I'll do a full inventory once I've received both lots (assuming I win the second one) and have moved house. If anyone needs anything, let me know. No Ferengi tactics here

Anders wouldn't be your friend anymore, I assume. 

[bd139]

bd are you bidding on the second transistor lot?

Yes and I have a lot of money to burn at the moment so will be bidding completely irresponsibly 

First lot due to be delivered today.

Edit: I'll do a full inventory once I've received both lots (assuming I win the second one) and have moved house. If anyone needs anything, let me know. No Ferengi tactics here

Anders wouldn't be your friend anymore, I assume. 

Depends if he wins or not 

[Cubdriver]

But do the Heathkit cloc-u-lators use the same size/height/type of display? Also Panaplex displays are used in some pinball machines in high quantities, probably in high demand there too. I'm sure "bigclive" shows the inside of one in a YT video, but it's probably OT and can't be posted here.

I never did add the pictures of mine, in a HP 432B (no auto ranging on 'B' model), it also has the same worn decimal point issue, but not so bad that it isn't visible. If it was replaced you would need to either transfer the over-range decal, or make a new one.





Also have a panel voltmeter that uses similar or the same displays. We had a very large cable crimp pull test machine at work with a similar panel meter, but it got scrapped without my knowledge, not that I could have rescued it anyway, due to the no you can't buy it policy ATM.  They are probably filling more skips, during the shutdown fortnight, as I post this. 

Here is my Data Tech panel DVM, almost looks unused in comparison to display in the HP 432B.







David

I do have replacements for the +/- 1.5 digit display coming, but hope to somehow avoid replacing it.  I’d been contemplating how to remove the overrange mask if push comes to shove - perhaps some gentle persuasion with a scalpel or single edge razor blade between it and the glass.

As a collector of such things, it sickens me when I hear of companies that insist that old but perfectly functional equipment be destroyed when they write it off.  It’s infuriating.

-Pat