I bought some of those smd resistor/cap "kit" books...sadly it was summer & they used some cheapo extra gummy labels...By the time it arrived the labels had all fallen off & were just a sticky clumpy mess in the package & the ink also "peeling off"....with all the approx 170 labels essentially missing, the book isn't so handy!https://www.amazon.ca/gp/product/B08P8TYQ2S/
Well, that was kind of the reason I posted. When you look at these listings, they're an unknown; I figured a post showing what actually arrived for my 9 bux and change would help my fellow Canucks make a informed decision. Also, being 0805, they're quite a nice size for hand work. Hard not to get your money's worth here. +--
EDIT: Woops! Looks like somebody took advantage... they've sold out the ones that were In Stock/Fulfilled by Amazon, and are now only shipping from China at CAD$45/copy. Hope those who partook enjoy their purchase!
mnem
*tsssssst...*
Put it in perspective this way:
What do you imagine the guys who designed your hollow-state wonders would have thought of that meter...?
Especially if you told them it could be bought new for the price of steak dinner at a roadhouse...?
mnem
Well if it's not linear as Med suggests and the specification is only 3 times better than an AVO 8, probably not too much.
Yep, but in reality, for what med does, it is perfectly usable, who has ever heard of Tektronix scope failing to function because the supply lines were 1mV adrift of their true voltage? Answer, nobody and nobody ever will.
Considering that's the Trabant of DMMs, that's still fairly good
Someone wanted a 3478? This one has no bids yet, and who knows how the seller might react to a careful offer?
What is a reasonable price these days? I had a new one on my desk at work many many years ago. Fab meter when new.
I'm hesistant to buy a used one because of the internal battery and potential loss of calibration. If it still has calibration data, I can change the battery. Recovering from lost cal data is not something I can do at home. I've only got a 2.5000V reference and a 9999 count DMM.
The one I scored has date codes suggesting a build date around late 1986 - early 1987, and the battery measures 3.03v. Perhaps of more immediate concern are the 4 RIFAs...
If you really want one, getting a clean one for £100 seems reasonable, but I wouldn't be in any hurry to bid higher as there doesn't seem to be a shortage of these.
Reader's Digest version: High-voltage film capacitors are no longer available in "tall skinny can" format, only big rectangular boxes. How do I attach the replacement capacitor securely when the new cap's footprint is to large to fit on the PCB?
Unabridged version: I just bought an HP 6209B DC power supply (0-320V 0-100mA) off of the estuary of wickedness. It's a late model, and a real beauty - traces were taped by hand and gold-plated. I was looking forward to long, blissful nights with just me, a 12AX7, and a high voltage power supply. Well, it turns out that one of the caps is making noise, the kind that can be detected by ear. The seller was a good sport and, at my suggestion, gave me a partial refund. The user manual is available online ( http://www.nousnexus.com/Manuals/HP_6209B.pdf ) and helpfully contains a schematic and parts list. The cap that failed is C20 - "film 25μf 475Vdc". It's a radial and ~30mm in diameter (see image, attached). I hop on digi-key and all of the 25μF film caps rated for >= 475VDC are boxes with footprints like 42x35mm. How the heck do I fit a large footprint component on a PCB designed for a tall skinny cap can? I was thinking that maybe I could build a little stand out of unclad FR-4 and gobs of silicone, and then plop the cap on top so it's raised off of the PCB (see DaveCAD, attached). Of course I would make something more structurally sound than what I sketched, but you get the idea. Is there a better way to solve this problem? Glue the cap to the side of the enclosure and run wires? Use multiple smaller caps in parallel? Use an electrolytic cap? Build my own capacitor? Give up and take up golf instead?
I'm not sure the description in the manual is correct, it says film for C20 but when you search the military part sites for 0180-1848 it is then described as an aluminium electrolytic, see here; https://www.parttarget.com/5910-01-311-5312_5910013115312_PFP250YN2A1P2.html/-18280EA8-7F78-47CF-815F-0CF3C4CD45F8
When you look up the Sprague DFP (one of the alternate parts) it is also an aluminium electrolytic, I think the manual is incorrect, this wouldn't be the first error we have seen in old manuals.
David
When is a Fluke not a Fluke? When it's a Mastech. Trying to calibrate the DCV is an exercise in futility. It is very non-linear across the DC range and getting an acceptable compromise is near impossible. Now it COULD be because I'm doing it wrong due to lack of service info. So I have to consider that. But for critical measurements this guy falls flat. So it will just be used to quickly check new stock capacitors.
That concludes all my calibrations for now except the Tek 2465 DMS with the DMM option. But that would involve lifting and that's a no-no right now. And the Type 547 sits there mocking me again. Now that it has good power I want to dive in and fix the remaining issues.Stop being so negative towards this meter, think you find it is actually pretty good, it is only 1mV out, and I think it will be well within its design specification, take at the data sheets below. I think I told mnem a lie, I think that the maker of these meters might well be Appa, so email them with a photo of yours and enquire there, you may just get lucky. Keep up the good behaviour and keep well clear of these heavy beasts that are mocking, they will still sitting there once you're mended, they aint going anywhere.
Well it's easy to meet the spec, DC volts 0.3% +_5 counts
This is supposed to be a4.5 digitmeter a mid range fluke 77 3.5 digit handheld does better, a 8010A is 0.1% _+1 count and a 8050A 4.5 digit does 0.03%
Edit, sorry it's 4000 count not 4.5 digit but still 0.3% +5 counts that isYep, but in reality, for what med does, it is perfectly usable, who has ever heard of Tektronix scope failing to function because the supply lines were 1mV adrift of their true voltage? Answer, nobody and nobody ever will.
Fact is if this was the only meter he or anybody else ever had, it would be best meter for the job in their tool kits and it would not affect their ability to repair things in any way whatsoever. It is a massive jump up from an analogue meter and we all managed perfectly with those before digital became a reality.
Well, regardless. I have 40 year old Flukes that run circles around it so in reality let's call it what it is. A POS.
Reader's Digest version: High-voltage film capacitors are no longer available in "tall skinny can" format, only big rectangular boxes. How do I attach the replacement capacitor securely when the new cap's footprint is to large to fit on the PCB?
<SNIP>
I'm not sure the description in the manual is correct, it says film for C20 but when you search the military part sites for 0180-1848 it is then described as an aluminium electrolytic, see here; https://www.parttarget.com/5910-01-311-5312_5910013115312_PFP250YN2A1P2.html/-18280EA8-7F78-47CF-815F-0CF3C4CD45F8
When you look up the Sprague DFP (one of the alternate parts) it is also an aluminium electrolytic, I think the manual is incorrect, this wouldn't be the first error we have seen in old manuals.
David
Yep, but in reality, for what med does, it is perfectly usable, who has ever heard of Tektronix scope failing to function because the supply lines were 1mV adrift of their true voltage? Answer, nobody and nobody ever will.
Wanna bet? The Type 1A1 plug-in in the Type 547 is 1mV off vertically on both channels which is totally unacceptable and will be investigated and fixed.
Put it into perspective, your Honda Civic in comparison to say a Cadillac Seville is a POS I dare say, but they both will get from point A to point B in reasonable comfort. Granted the Cadillac is several grades higher up the quality stakes and price stakes, just as the 40 years old Fluke is to the Mastech, they are not directly comparable.
Yep, but in reality, for what med does, it is perfectly usable, who has ever heard of Tektronix scope failing to function because the supply lines were 1mV adrift of their true voltage? Answer, nobody and nobody ever will.
Wanna bet? The Type 1A1 plug-in in the Type 547 is 1mV off vertically on both channels which is totally unacceptable and will be investigated and fixed.Does it work? Yes it does, does the workshop manual state that the 1mV is critical? NO. You are making it critical because it does not sit comfortably with your OCD. I think that the figures quoted in the workshop manual have a fair degree of margins that as long as the voltages are within those parameters it is deemed to be fine. Even digital scopes unless paying thousands for them still have margins of around 3% for their digital readings on screen, which I wager are going to be far better than judging a reading against a graticule can ever be, even with perfect vision.
Yep, but in reality, for what med does, it is perfectly usable, who has ever heard of Tektronix scope failing to function because the supply lines were 1mV adrift of their true voltage? Answer, nobody and nobody ever will.
Wanna bet? The Type 1A1 plug-in in the Type 547 is 1mV off vertically on both channels which is totally unacceptable and will be investigated and fixed.Does it work? Yes it does, does the workshop manual state that the 1mV is critical? NO. You are making it critical because it does not sit comfortably with your OCD. I think that the figures quoted in the workshop manual have a fair degree of margins that as long as the voltages are within those parameters it is deemed to be fine. Even digital scopes unless paying thousands for them still have margins of around 3% for their digital readings on screen, which I wager are going to be far better than judging a reading against a graticule can ever be, even with perfect vision.
Yes, the acceptable tolerance is 3%. But being 1mV low on a 5mV signal is certainly NOT 3%.
...
July 2, 2021, 2:52 am
Departed USPS Regional Facility
MINNEAPOLIS MN DISTRIBUTION CENTER
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Arrived at USPS Regional Facility
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Arrived at USPS Facility
MINNEAPOLIS, MN 55413
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July 1, 2021, 7:57 pm
Departed USPS Facility
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Arrived at USPS Regional Facility
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June 30, 2021, 10:59 pm
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Put it in perspective this way:
What do you imagine the guys who designed your hollow-state wonders would have thought of that meter...?
mnem
Well if it's not linear as Med suggests and the specification is only 3 times better than an AVO 8, probably not too much.
Yep, but in reality, for what med does, it is perfectly usable, who has ever heard of Tektronix scope failing to function because the supply lines were 1mV adrift of their true voltage? Answer, nobody and nobody ever will.
Wanna bet? The Type 1A1 plug-in in the Type 547 is 1mV off vertically on both channels which is totally unacceptable and will be investigated and fixed.
I don't use the AD584-M's when checking scope inputs. I use a home built fixed square/triangle/sine calibrator plus a function generator. And the outputs are proven accurate and stable over dozens of years and dozens of scope calibrations. So I trust what it's telling me. And the Heath IG-4244 comes into play for compensation adjustments.
In the case of the Type 1A1 plug-in the inaccurate gain carries through in the upper ranges too. A 500mV p-p signal results in an 400mV p-p display. And the gain pot is topped out. The gain adjustment should allow me to go above 500mV p-p but it doesn't and that's clearly a defect.
And it's not a matter of incompatibility. The Type 1A1 can be used in an older Type 535A even though it has a 50Mhz B/W compared to the Type 535A 15Mhz B/W.
And yes, I have OCD but if there's clearly a defect I'm going to do all I can to fix it. The above is a defect.
Always getting on Discord for not having a working Mic so prior to delivering a new scope to a large audio crowd some horse trading was arranged and access to their E-Waste room was approved.
Some fixing first might be required however but still quite pleased with the score.
Surely I can get one of the Mic I/O's working.
Now to look for manuals etc
Found in a jiffy:
https://www.soundcraft.com/en/product_documents/notepadusermanual_v-1-0-pdf
A Fabricobbledy Monday Morning Project:
The resistors were waiting in my mailbox this morning after brekkerz; I decided to step back from that Pioneer to get a start on something useful, so pulled the heatsink from that black behemoth monoblock amp to make this. 20 m3 holes drilled and tapped with the same bit/tap, all by hand with cordless drill. Even had to tap the holes with the drill too... Okay, I didn't have to, but I preferred to as I didn't have a proper ratcheting tap handle to use.
Still to come: Terminals on the way, and designing/printing bits to hold them and a 120mm fan...
Now I know y'all will have misgivings aboot something like this actually dissipating 150-200W and being made almost entirely of low-temp thermoplastic. I do as well, to some extent. However, this whole stack sits quite solidly on top of that fan without even having a frame around it; I'm reasonably certain that it's going to be fine for its intended purpose, as it will never be used for anything but low-voltage loads.
mnem
*knocks self unconscious with a decibel mallet*