Is this enough fine control of wattage...? They make these for putting lots of cheap LED floodlights in the garage; I've used one with appliance bulbs to fine-adjust max current on my dim-bulb tester. Costs $10-15 on Amazon: https://www.amazon.com/s?k=bulb+splitter+7+in+1
Interesting !
However no it still does not cut it. It makes it more practical to adapt the wattage to the DUT, but still is an on/off safety device. I was talking about fine control as far as ramping up the voltage slowly. A dim bulb tester is no help for this, no matter how fancy one makes it.
Yeah, I'd still want one of these inline with a variac, myself. A lot of the time you'll find that once things start turning on in a SMPS, especially the older designs, that's when a short appears. The scariac doesn't stop the magic smoke from coming out then, but rather encourages the switcher transistor to try and sink more current to make up for the lower voltage.
mnem
Hopefully, the notification service of postings being made will be back up and running next?. Judging by the lack of postings here now, I guess that there was only a handful of us making regular checks to see if the server was back on line?
What was I saying about using "the cloud" for everthing last week....
And "the cloud" is immune to fires in the server building?
McBryce.
What was I saying about using "the cloud" for everthing last week....
Edit: I notice the forum is running like shit now as well. Another problem easily resolved by upping the instance size transparently rather than buying another physical machine
What was I saying about using "the cloud" for everthing last week....
And "the cloud" is immune to fires in the server building?
McBryce.My point was it is a bad thing, it was in relation to having a micro SD card in a phone for local storage and backup.
Ah, ok. I've (the company I worked for) already had massive problems that cost millions due to lost cloud data.
What was I saying about using "the cloud" for everthing last week....
Nice pic, looks cleaner for sure, brand new. Looks like you trained your camera well, it knows its stuff now : it automagically focused the picture on the trouble maker : that yellow dipped tantalum cap ! Good camera, good camera !
Is this enough fine control of wattage...? They make these for putting lots of cheap LED floodlights in the garage; I've used one with appliance bulbs to fine-adjust max current on my dim-bulb tester. Costs $10-15 on Amazon: https://www.amazon.com/s?k=bulb+splitter+7+in+1
Interesting !
However no it still does not cut it. It makes it more practical to adapt the wattage to the DUT, but still is an on/off safety device. I was talking about fine control as far as ramping up the voltage slowly. A dim bulb tester is no help for this, no matter how fancy one makes it.
Yeah, I'd still want one of these inline with a variac, myself. A lot of the time you'll find that once things start turning on in a SMPS, especially the older designs, that's when a short appears. The scariac doesn't stop the magic smoke from coming out then, but rather encourages the switcher transistor to try and sink more current to make up for the lower voltage.
mnem
I don't think I'd try to soft start an SMPS with a variac; an SMPS is a constant power device, it'll just draw more current at lower voltages...
And the data security argument is void. What you post on a public forum is public. What you post in a private S3 bucket in AWS is not.
Yeah I'd buy one but not for that. Main advantage is it has RS232 which means no PITA GPIB adapter required.
So you're saying the fact of GPIB-only is the reason the 3478A gets no respect...?Seems way overpriced to me, considering a working 3478A can be had for ~100 quid almost any day; less if you can be patient and shop carefully.Shameful, actually; for some reason the 3478A just gets no respect.
Is it just the 3478A, or any HP gear of that generation, ie with that horrible tiny hard to read LCD that almost nobody likes ? LED or VFD gears are so much easier to read, from a distance, at any angle, whatever the lighting conditions dark or bright.
Maybe if they had made a much larger LCD with digits 3 times as tall, fatter segments, and a bright and even backlight... people would value them more ? Still, you would still have the viewing angle problem.which neither LED or VFD suffer from.
At any rate this LCD is a killer for me personally. I would rather get an older gear with LED displays (still small but easy to read and no viewing angle problem), or save some more money and get a newer generation with VFD.
Having lived with one everyday for a while... the transflective LCD on the 3478A is very good for the breed. Viewing angle is quite wide, and unless you like to work on a dark bench, the fact of passive display is a total non-issue.
I think the problem is
a) not sexy; everything aboot it screams "dumptruck" design ethos.
2) general ignorance aboot B/L vs non-B/L display; folks pre-judge it and just say "pass..." because they've never actually had one.
Bottom line is the 3478A is one of the most straightforward UI, generally easy-to-use meters ever made. If not for the fact they're proportioned like a Dachshund (dog and a half-long; half a dog wide) they'd be the perfect all-around bench meter.
mnem
Well, we're still running!Nice pic, looks cleaner for sure, brand new. Looks like you trained your camera well, it knows its stuff now : it automagically focused the picture on the trouble maker : that yellow dipped tantalum cap ! Good camera, good camera !
OK Vince, now with your keen eye you pointed out a tantalum cap in one of my pics of the hp E3611A - a trouble maker as you stated. That happens to be the only one in the parts list - a 6.8 uF 35V.
Now, that happens to be a 3-legged tantalum. Works the same as a 2-legged. They made them so that they couldn't be installed backwards. Although there are no polarity markings on it, I checked the schematic and the center pin should be positive. Also indicated by a voltage check too.
I'll let you decide, since you are appreciative of vintage test equipment - do you say it's OK to put in a 3-legged part in it's place, just to keep it original.
Thanks.
And the data security argument is void. What you post on a public forum is public. What you post in a private S3 bucket in AWS is not.
Unless you you leave your S3 bucket credentials on Github.
The 3 leg tant's are made for low impedance, not being reversable. Unless it has more then 25V DC on it I'd let it stay where it is.
Just snagged a tidy Fluke 8060A on ebay for £42.20 inc post![]()
The faulty "display fades" does not bother me. either a dirty zebra strip or dodgy capacitor. Should not be too hard to fix and everybody needs at least 3 8060As
www.ebay.co.uk/itm/Fluke-8060A/154397971430
Now, what was I saying before I was interrupted by someone sneeking off behind the generator shack for a quick fag? Oh yes, OCXOs.
So, my batch from what turned into a distributed group purchase took 9 days door to door. Ordered two and like BD, got twice as many for my money.
Desoldering turned out to be relatively easy for a part on a 10 layer board - just desoldered each pin with Chem-Wik (that stuff's good) and went around the board with a small screwdriver for a lever and gave each pin a lift while heating it with the old Metcal. No application of 60/40, chip-qwik or anything similar needed.
All four survived the ordeal of having the board next to them violently cut and being desoldered. Here's how they all performed:
Sorry for the laziness of a screenshot, but converting to SMF's table notation is too much of a fag. Readings taken with my TTi TF930 that was last adjusted against GPS a year ago.
All with enough range left to be steerable to 10.000 000 00 MHz at an appropriate EFC voltage with room to spare for future ageing (i.e. GPSDO fodder). None good enough to be used "out of the box" as a 10 MHz reference without trimming, unless you were more interested in stability than accuracy.
I tried a few random selections for stability, using another known good uncalibrated 10 MHz OCXO as reference input to the TF930, and they stayed stable at the limit of the counter's resolution (10 mHz or 1 ppb) for as long as I was prepared to wait - several hours in one case.
Conclusion: £13.90 well spent.