Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

I guess they were going for it to be "like small incandescent bulbs"?

It's the gentle warm glow of an open fire -  to distract you from the self-immolating RIFAs

[Specmaster]

I guess they were going for it to be "like small incandescent bulbs"?

It's the gentle warm glow of an open fire -  to distract you from the self-immolating RIFAs

I know I was glad that I did replace the LEDs on both of mine, it brought the display up to a similar level as that on a modern hand held meter with a lit display and thus made it equally as easy to quickly and effectively read the display just as easily as you can a meter that has LED's or a VFD type of readout.

[AVGresponding]

To each, his own.

[extremgear]

Hello,
Second 34478a 3478A has arrived , came with a power cord and seems to be compatible with windows 10 this time . , the rear is a little bit broken but otherwise it looks in good condition, the transformer tap will have to be changed from 220V to 240V too.
i didn't open it yet, sold as a working unit , i will see that in the afternoon , i'm still a waiting for the " maintenance kit " ( capacitor battery etc..) i ordered last week.
i also "scored" a keysight 34461A that should come by the end of the week.

[TERRA Operative]

How is a 3478A (I assume 34478A is a typo?) compatible with Windows 10? Only your GPIB adapter needs to be compatible.

[timeandfrequency]

Second 34478a has arrived
[...]

Yes, the photos show a venerable HP3478A.
And luckily, this stuff also works great in standalone mode (as does the SEB toaster in the background). No need for any computer to perform the usual measurements.

To supplement what @TERRA Operative has indicated, a computer is only necessary if you need to record/store/post-process your measurements or if you intend to automate or remote control your multimeter, for example, if it is mounted on a test bench.

I also red in previous posts of yours that you expect to backup the cal values ​​via GPIB. Well, it might be interesting, but not really essential.
What is more important is to hook every few years (in case of private use) your multimeter to a calibrator in order to verify if it's still in its specs.

[ch_scr]

How is a 3478A (I assume 34478A is a typo?) compatible with Windows 10? Only your GPIB adapter needs to be compatible.

I think he meant, that he for some reason also got shipped an HP leaflet with the DMM. It can be seen, sitting on the DMM. Said leaflet, supposedly for some kind of HP computer or accessory, mentions Windows 10 compatibility...

[extremgear]

How is a 3478A (I assume 34478A is a typo?) compatible with Windows 10? Only your GPIB adapter needs to be compatible.

Second 34478a has arrived
[...]

Yes, the photos show a venerable HP3478A.
And luckily, this stuff also works great in standalone mode. No need for any computer to perform the usual measurements.

To supplement what @TERRA Operative has indicated, a computer is only necessary if you need to record/store/post-process your measurements or if you intend to automate or remote control your multimeter, for example, if it is mounted on a test bench.

it was a joke because the seller probably found funny to include a recent hp manual that say "compatible with windows 10" with a 30 years old device ( maybe from a printer )

How is a 3478A (I assume 34478A is a typo?) compatible with Windows 10? Only your GPIB adapter needs to be compatible.

I think he meant, that he for some reason also got shipped an HP leaflet with the DMM. It can be seen, sitting on the DMM. Said leaflet, supposedly for some kind of HP computer or accessory, mentions Windows 10 compatibility...

i opened the multimeter it is a 1994 - 1995 model , the inside is nice too , and it looks to work too.
the electrolytics caps are ok i won't change them this time , the rifas looks ok but i'll change them anyway , the battery is 3,4v and is probably 30 years old.

[timeandfrequency]

it was a joke because the seller probably found funny to include a recent hp manual that say "compatible with windows 10" with a 30 years old device ( maybe from a printer )

Yes, a few thread attendees found that funny too.
Its guts are in neat condition.

[TERRA Operative]

How is a 3478A (I assume 34478A is a typo?) compatible with Windows 10? Only your GPIB adapter needs to be compatible.

Second 34478a has arrived
[...]

Yes, the photos show a venerable HP3478A.
And luckily, this stuff also works great in standalone mode. No need for any computer to perform the usual measurements.

To supplement what @TERRA Operative has indicated, a computer is only necessary if you need to record/store/post-process your measurements or if you intend to automate or remote control your multimeter, for example, if it is mounted on a test bench.

it was a joke because the seller probably found funny to include a recent hp manual that say "compatible with windows 10" with a 30 years old device ( maybe from a printer )

Yep, I totally missed that one.

As you say, a set of replacement caps for those Rifas, and a new backup battery and you'll have a nice meter.
Just be sure to either back up the cal constants, or connect a temporary battery in parallel (I use two AA batteries in a holder soldered to convenient points on the PCB) so you don't lose the cal data when you replace it.

You can also do a backlight mod on the LCD display for better visibility too. I'll edit the video on how I did mine one day and upload it to youtube.

[extremgear]

How is a 3478A (I assume 34478A is a typo?) compatible with Windows 10? Only your GPIB adapter needs to be compatible.

Yep, I totally missed that one.

As you say, a set of replacement caps for those Rifas, and a new backup battery and you'll have a nice meter.
Just be sure to either back up the cal constants, or connect a temporary battery in parallel (I use two AA batteries in a holder soldered to convenient points on the PCB) so you don't lose the cal data when you replace it.

You can also do a backlight mod on the LCD display for better visibility too. I'll edit the video on how I did mine one day and upload it to youtube.

yes i plan to back up the cal constants just in case i mess up with the battery replacement.
backlighting: why not !

[McBryce]

How is a 3478A (I assume 34478A is a typo?) compatible with Windows 10? Only your GPIB adapter needs to be compatible.

Yep, I totally missed that one.

As you say, a set of replacement caps for those Rifas, and a new backup battery and you'll have a nice meter.
Just be sure to either back up the cal constants, or connect a temporary battery in parallel (I use two AA batteries in a holder soldered to convenient points on the PCB) so you don't lose the cal data when you replace it.

You can also do a backlight mod on the LCD display for better visibility too. I'll edit the video on how I did mine one day and upload it to youtube.

yes i plan to back up the cal constants just in case i mess up with the battery replacement.
backlighting: why not !

And make sure you solder/de-solder the battery with a non-earthed iron to avoid a short to ground which will ruin your day. I used a gas iron (Portasol) to replace the battery in mine.

McBryce.

[TERRA Operative]

You can just not have the meter plugged in while working on it.

[tggzzz]

You can just not have the meter plugged in while working on it.

Yes, repeat no.

If it is like the hp3468 then yes, you can. But if the soldering iron is connected to the mains, then the grounded tip will short out the battery - and the calibration constants will be lost.

So, either have it connected to the mains and use a battery/gas soldering iron to replace the battery, or don't connect it to the mains but do connect another battery in parallel[1] and replace the battery.

There are several explicit guides on how to do this.

[1] not quite. The connection has to be on the other side of a diode used to "isolate" the battery when mains power is applied.

[AVGresponding]

How can you short it to ground if it's not plugged in? And who tf solders their TE with it plugged in?

I could understand if you meant "don't short any pins together with a big soldering iron tip".

[vk6zgo]

How can you short it to ground if it's not plugged in? And who tf solders their TE with it plugged in?

I could understand if you meant "don't short any pins together with a big soldering iron tip".

I think the point is that with the device unplugged from power, the only thing keeping the volatile memory alive is the battery, even if it is "on its last legs".
If the battery is completely dead & you have stuff you don't want to lose, turning it off would be a problem, so that is why people remove & replace the battery with power on.

There is an alternative to a battery or gas iron---If you have some versions (certainly mine) of the Weller WTCP, which do not tie the iron tip to Mains Earth.
In those units, there is no ohmic connection between the iron tip, & any part of the Mains supply due to the primary to secondary isolation of the transformer.
I remember, years ago, such irons modified with a switch to provide or remove tip earthing as required.

Later ones seem to have the tip connected to Earth, so that trick would require you to open the transformer box up & temporarily "float" the tip.

[McBryce]

And who tf solders their TE with it plugged in?

People who want to retain their calibration data without having to faff around with a second battery.

McBryce.

[extremgear]

my 2 soldering irons can have the earthing of the tip switched off, so it's not a problem.
But i don't think i will change the battery with the meter energised anyway and on the first meter i also have to change the 3300uf cap: that is another risky task .
i'll probably add an other 3V source .

[TERRA Operative]

And who tf solders their TE with it plugged in?

People who want to retain their calibration data without having to faff around with a second battery.

McBryce.

So instead faff around working on live equipment..... 


I'll take the safer route and use batteries and not risk blowing stuff up or working near exposed terminals at mains potential.
I've received enough electric shocks in my lifetime as an electrician......

[extremgear]

electric choc can be easily avoided by wearing proper gloves but short circuit is another story .

[Specmaster]

my 2 soldering irons can have the earthing of the tip switched off, so it's not a problem.
But i don't think i will change the battery with the meter energised anyway and on the first meter i also have to change the 3300uf cap: that is another risky task .
i'll probably add an other 3V source .

You can still come a gutser, though, as I did with mine. Had it all unplugged, tagged in another 3v supply further along in the circuit  so I did not accidentally disconnect both 3V supplies while disconnecting the battery. I had my solder still attached to the roll and unrolled a length to use, unfortunately, while attempting to solder back in the new battery, I let the solder hang across the case frame, and it temporarily shorted the battery thus dragging the power rail on the ram chip to zero and wiping out the stored calibration data. Luckily, it is not that hard to recalibrate as long as you have some known values or a suitable meter that can be used as a transfer standard.

[McBryce]

And who tf solders their TE with it plugged in?

People who want to retain their calibration data without having to faff around with a second battery.

McBryce.

So instead faff around working on live equipment..... 


I'll take the safer route and use batteries and not risk blowing stuff up or working near exposed terminals at mains potential.
I've received enough electric shocks in my lifetime as an electrician......

The live parts of the 3478A circuit are far enough away from the battery and can also be easily covered.

McBryce.

[BU508A]

And who tf solders their TE with it plugged in?

People who want to retain their calibration data without having to faff around with a second battery.

McBryce.

So instead faff around working on live equipment..... 


I'll take the safer route and use batteries and not risk blowing stuff up or working near exposed terminals at mains potential.
I've received enough electric shocks in my lifetime as an electrician......

The live parts of the 3478A circuit are far enough away from the battery and can also be easily covered.

McBryce.

I believe it is better to train habits which are generally safer than taking convenient shortcuts.
Means: the shortcut may work for this device but it might not be a good idea for another.

So, just doing it the safe way all the time, one does not have to think about it.
Just as easy as putting on your seatbelt when you get into the car.

[AVGresponding]

Let me just leave a couple of pictures of electrical burns here, for the complacent amongst you to contemplate.





And by the way these are some of the mildest of the pictures you find when googling electrical burns. Don't look at the others unless you have a strong stomach.

[ch_scr]

[...]
So, just doing it the safe way all the time, one does not have to think about it.
Just as easy as putting on your seatbelt when you get into the car.

Ah, I see we are putting out the real controversial opinions now!

But on a more serious note, I agree: the shortcut will become a habit and might lead to an accident. Some say it's one of the most common ways...

To me, now only one question remains: if you use an external supply to support the Ram, is it a good idea to set the current limit low or high?
If it is high enough, an accidental short might be cleared momentarily by itself