I bought one of these a few years ago. My label looks a bit different and was filled in by hand. The PCB looks the same, and the top acrylic labeling looks the same. On the side, mine has "KMOON" branding. One other interesting difference is that mine is populated with the AD584KH part; I think you had "JH" version instead? I noticed that the device on the board looked like a "pull" from something else; the metal case of the part looks worn or scuffed. As far as I'm concerned, this is "feature" not a bug.. the part has been pre-aged prior to landing on my doorstep. I check the measurements against my Fluke 8050A (4.5 digit DMM) and Fluke 8840A (5.5 digit DMM) and they match pretty closely. Those both agree well with each other, despite being surplus purchases. I have a Fluke 87-III handled DMM that's actually a bit further out from both of those and the reference, though still within spec. So like a man with two wristwatches; WWVB synced clock and GPS synced clock, not only don't I know what time it is, I can never be completely sure what the voltage is :-)
2013-11-54 is the date? On what planet? 😕 I did a google translate, it says "Number" to the left, not "Date". I think it's a serial number that just happens to look like a date. It's great that they put the temperature on the case, but it doesn't say the warm-up time. I wouldn't use this right after charging the cell, which would create heat and make the device hotter inside than ambient. I doubt it needs charged very often. Any way to test the battery voltage, perhaps when it's unplugged on the output terminals? Usually these devices want to see a 1% variation to the input voltage, it would be good to always have the cell charged to the same voltage. How useful do you find the extra output voltages? I made a 10V calibrator from LM399+OP177 and had considered adding other voltages, but avoided overcomplicating the task.
@ IMSAI Guy No, label with measured voltages is REPRINTED BULLSHIT... Nobody cares about checking voltages of this thing, so they checked once and reprint label on everyone device. The best thing you can do is take as a refference accuracy according to IC's datasheet. A friend of mine bought not excatly this pcb, but different one on the same chip, checked by yourself voltage accuracy with calibrated 6 digits meter and it doesn't match, so in my opinion it doesn't matter which one version you buy, label with measured voltages is reprinted bullshit not of your copy...
I'll tell you what, NO WAY that label is generic and all 4 outputs match the content creators 34401A w/in 40μV at 7.5V and 10V, and w/in 10μV at 2.5V and 5V. I'm AMAZED. I have a stack of calibrated 34401A's that don't agree on a PARALLEL input that closely -- thanks MICRO PRECISION CALIBRATION 😢👎.
Usually if you can see enough reviews with pictures of the device, you can see the label is different for each buyer. I have yet to see or hear about a reprint. I think this video demonstrates the value was likely correct. Some devices have handwritten values, this one someone took the time to enter them into the computer for a nice legible printout and serial number for tracking.
![HeathBuilt Voltage Reference Source [Restoration]](http://i.ytimg.com/vi/2LlOGOu8Dlg/mqdefault.jpg)
I am really enjoying your content, thanks!
Seems like a good voltage reference. Thank you for sharing !
I bought one of these a few years ago. My label looks a bit different and was filled in by hand. The PCB looks the same, and the top acrylic labeling looks the same. On the side, mine has "KMOON" branding. One other interesting difference is that mine is populated with the AD584KH part; I think you had "JH" version instead?
I noticed that the device on the board looked like a "pull" from something else; the metal case of the part looks worn or scuffed. As far as I'm concerned, this is "feature" not a bug.. the part has been pre-aged prior to landing on my doorstep.
I check the measurements against my Fluke 8050A (4.5 digit DMM) and Fluke 8840A (5.5 digit DMM) and they match pretty closely. Those both agree well with each other, despite being surplus purchases. I have a Fluke 87-III handled DMM that's actually a bit further out from both of those and the reference, though still within spec. So like a man with two wristwatches; WWVB synced clock and GPS synced clock, not only don't I know what time it is, I can never be completely sure what the voltage is :-)
On my Christmas list
Fluke 187 accuracy at 10 V is within 2.5 mV.
2013-11-54 is the date? On what planet? 😕 I did a google translate, it says "Number" to the left, not "Date". I think it's a serial number that just happens to look like a date. It's great that they put the temperature on the case, but it doesn't say the warm-up time. I wouldn't use this right after charging the cell, which would create heat and make the device hotter inside than ambient. I doubt it needs charged very often. Any way to test the battery voltage, perhaps when it's unplugged on the output terminals? Usually these devices want to see a 1% variation to the input voltage, it would be good to always have the cell charged to the same voltage. How useful do you find the extra output voltages? I made a 10V calibrator from LM399+OP177 and had considered adding other voltages, but avoided overcomplicating the task.
you might be interested in the 399 insides: ua-cam.com/video/6hXzuLKzXmg/v-deo.htmlsi=neXzajR7eUJt5MOf
@
IMSAI Guy
No, label with measured voltages is REPRINTED BULLSHIT... Nobody cares about checking voltages of this thing, so they checked once and reprint label on everyone device. The best thing you can do is take as a refference accuracy according to IC's datasheet. A friend of mine bought not excatly this pcb, but different one on the same chip, checked by yourself voltage accuracy with calibrated 6 digits meter and it doesn't match, so in my opinion it doesn't matter which one version you buy, label with measured voltages is reprinted bullshit not of your copy...
That is too bad. I bought mine 7 years ago. I guess the Chinese decided to clone it. sad
I'll tell you what, NO WAY that label is generic and all 4 outputs match the content creators 34401A w/in 40μV at 7.5V and 10V, and w/in 10μV at 2.5V and 5V. I'm AMAZED. I have a stack of calibrated 34401A's that don't agree on a PARALLEL input that closely -- thanks MICRO PRECISION CALIBRATION 😢👎.
Usually if you can see enough reviews with pictures of the device, you can see the label is different for each buyer. I have yet to see or hear about a reprint. I think this video demonstrates the value was likely correct. Some devices have handwritten values, this one someone took the time to enter them into the computer for a nice legible printout and serial number for tracking.