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Re: my new psu
Found your pics in photo section. Labeling on transformer yields 1A across all windings, likely because
they are all a common center tap. I would expect the 6.3v winding to be around 3Amps? Is there just the single 6.3, or is it split into 5 / 6.3? In a couple of the pics, 20241129_160556.jpg and 20241129_152617.jpg, the transformer appears to have been stressed. Appears that there is some discoloration already, though may just be a light artififact when pic was taken. Bear in mind that that transformer has a lot of windings on it, and 1 intended (main) to be used at a time. You draw double the current, and you may end up saturating the core. Not good. You might get away with drawing greater current at a lower voltage winding, but looks like you are already connected to the 45v tag. Higher Voltage? No way would I do that as the supply sits. Pass transistors exhibit wear on cases, hope surface of the mica insulators is not compromised. 1 transistor likely for voltage, other for current. If supply set for 5, and transformer is connected at 45, with a 1A draw, the voltage pass transistor is going to be dissipating ((45-5)x1) 45 watts of heat. Doubling that to 2amps and you likely are going way outside design specs and looking at a much higher junction temperature in the transistor. Plus, you don't know how close the main caps and such are in relation to working voltage rating compared to actual voltage. If a diode has become 'leaky' and allows excessive ripple to pass, working voltage rating may be exceeded. Similar for the (National Semi?) old plastic pill style transistors. Had a bit of a time dating that power supply, was going to peg it around 1978 to 1980 based on component and wiring styles. But, I saw that one of the meters has a 0272 date code, translating to 2nd week of 1972 if the meter is original. Ultimately it comes down to are you willing to stress the supply given its age by exceeding ratings that are present on at least some of the components? If it were me, that would be a NO until I can slowly check it out. I am quite curious, as to what is connected to the 6.3vac windings? Are they supplying the heater for a valve rectifier? If so, got a part number? The meters are likely going to be a 50uA moving coil variety. Have you considered scrapping the internals, then retrofit with off the shelf variable Boost / Buck regulator supplied by a larger transformer, possibly a 100w laptop power supply (20v @ 5A)? I would think would be much tighter on output than a supply that is 52 years old, despite its brethren (like 5002) having excellent characteristics. ~SD |
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Re: oscilations in my amplifier ruins my PLL
Oscillations in a closed loop system are almost always caused by excessive loop gain.? Try reducing the gain in your feedback amplifier.? You should also ensure that your system is linear over the frequency range of your desired operation.? Gain instability can also be caused by amplifier non-linearities.? Check the gain on your EFC since this is a high Q device you may need to attenuate the output before sending it to the YIG mixer. Sam |
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Re: Archival data storage
wn4isx
One trick used in high density hard files is two layers of magnetic media with a thin neutral layer between them, each later is magnetized oppositely which is supposed to element room temperature self erasure.
The high density high speed hard files I installed in the digital video edit suites were made this way.
I have no idea how well it works, the people I installled the systems for sold their business to a national chain with their own tech support.
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It seems as though the neutral layer was 3 or 4 atoms thick.
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All media fails in the long run.
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Re: Archival data storage
¿ªÔÆÌåÓýtwo additional failure modes:1] Tape as described was the older plastic bases, but in addition there is a failure mode of the tape and hard drives self de-magnetizing due to room temperature thermal effects.? Essentially all magnetic media uses magnetic particles with a certain coercivity. The smaller the particle as for higher the bit density, the easier it is to self demagnetize unless the particle is of higher coercivity, but the harder it is to magnetize it.? This properties are balanced in the design/production to some number of years.? As I recall floppy disks and tape of that era the lifetime was about 20 years. 2] A more modern problem is the use of helium in the hard drives in order to fly the heads closer to the disk.? Helium leaks significantly in any system with soft (elastomer) gaskets that will be a feature of any hard drive.? I don't know what the number is today, but I suspect that number is in the 20 year frame also. Regards, Charles Patton On 12/5/2024 9:33 AM, David Slipper via
groups.io wrote:
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Re: Archival data storage
wn4isx
One of my wife's cousin is a bean counter. Yea I know the shame of it. She was down to finalize my deceased mother in law's estate. [Don't die, it is a mess] ? I mentioned storing and backing up data archives. Part of her duties is to serve on a committee that decides "What do we archive?" and "What archival media do we transfer?" ? She explained there are 4 primary costs to data archives. ? 1) A space to store the archive, space isn't free and archives typically require climate control and access security. ? 2) The cost of backup hardware and media, which may be extensive. Let's say for some insane reason you just discovered 1000 5.25 and 8 inch floppies, even worse the 8 inch are about 50/50 hard and soft sector. You'd have to locate working drives, I don't think there are any 8 inch drives that read both hard and soft sector. ? [They ran into this and decided none of the data was worth transferring, it was I-Omega Zip drives and a bunch of floppies.] ? 3) you'd have the cost of the backup media. ? 4) There is the labor costs of actually doing the backups, and a space to do the transfer. ? So, you have to ask yourself, "Is the data worth the time and expense to transfer?" ? Most of my archive probably falls under "Why in the hell did I print that webpage to PDF?" ? Consider.... MTV/Paramount deleted ~30 years worth of old programs. https://www.usatoday.com/story/tech/news/2024/06/26/mtv-news-archives-deleted/74225789007/ ? A youtube video on the subject https://www.youtube.com/watch?v=yLdi7Kp62bU ? Do a net search "youtube deleted 30 years of video" for more stories then you'd believe. ? [Some people are upset because the early history of hip-hop has been lost. I'm so unsad I can giggle.] ? I worked in a media center with several tens of thousands of hours of film, slides, photos, shellac phono records, various audio tape formats and various formats of video. ? I worked with video so I'm way too familiar with the problems of video tape. ? Our oldest video tape was Japanese 1/2 EIJ, open reel to reel video recorder. By the time I was hired in 1979 we couldn't locate a working machine to transfer the video tape. EIJ tapes suffered from striction. ? Our film chain died in 1995, a projector for NTSC TV has a pull down of 5 per second instead of the standard 4. We couldn't locate repair parts and the campus machine shop tried but couldn't fabricate a replacement part with the required accuracy. ? We had several hundred hours of Ampex 2 inch quadraplex. The tape heads were good for a few hundred hours and then had to be sent off for a rebuild. The only company that did the rebuilding went out of business and we faced the tough decision "Which tapes do we transfer?" ? We drew up a priority list and copied just over 70 tapes to U-matic 3/4" and Betacam (not home Beta!). This disrupted our normal operations for over a month. ? Then they nuked the entire media department and we shut everything down per written orders. "Everything" meant the HVAC. The archive was destroyed by the first frost. The room the archive was in would reach temperatures of 130 without HVAC. ? So they had no issue with "What do we save?" because it was all ruined. ? I attended a meeting 6 months after they shut us down, I charged them big time, and it was decided "We should have kept the TV department open until we backed up valuable media and transferred it to the official university archive." ? It would have taken the entire engineering staff 6 to 12 months to transfer the most important videos. ? Since they were in a severe budget crunch, was the lost video worth preserving? ? Don't ask me, I was an engineer and my opinion was irrelevant. ? ? I hope I've made it clear backing up data is important but not cost free and not all data needs to be archived. ? I'm a bit OCD and still have report cards from elementary school. The comments by my teachers are high humor. ? My wife wonders why some of my teachers didn't just strangle me. They did not approve of my enjoyment of 'bail out.' That's where you swing as high as you can, release and land in a paratroopers roll. I was school camp. Which is hilarious given my fear of heights. ? [We so won't go into Terry's cryptography that tried to pass as proper writting.] |
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Re: Archival data storage
wn4isx
After more research it looks like the best long term archival storage are glass CD/DVD and film on Mylar substrate because Mylar is extremely stable.
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And then there is this...
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Sorry for the long link
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opinion hit piece
One factor that has made the Intelligence State possible is cheap mass storage.
I was amazed when I applied for a state job and to verify my ID they asked me "What vehicle did you own in 1968?" I was 17 then and owned a Honda 90cc motorcycle.
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I thought, "Who on God's green earth would save data from 1968 on what vehicle I owned."
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A cousin (who has since died) was a deputy and let me see my NCIC file.
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Boring.
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This was 1996 and the main entry was "Approached to work for DIA and refused. Had security clearance from 1973 through 1979 for project...." [I was the tech for a airborne magnetometer pipeline survey and won't reveal the project name.] It listed my combination license, motorcycle and car, ham license and a list of my relatives, most of whom I'd never met, and a few other bits of data.
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[The DIA approached me as a senior in high school. I considered the offer but my father promised to break my arms if I agreed....and the thought of me as a DIA analyst still makes me giggle. If I was the best and brightest...good thing WWIII never happened.]
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I wonder what they have stored now....like the FBI keeps a list of "known associates." So if a friend from high school turned into a dope dealer, I'm probably tied to 'him'.
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Oh, a former duputy from KY was wanted for murder, a cop drove through a motel parking lot and his license plate reader popped up "This car is tied to a person wanted for a murder warrant."
That was a good use, but, and I don't care, imagine what can be determined by knowing when and where my care is on a monthly basis.?
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Or consider cell phone companies keep location data for you for unknown lengths of time and share it with whomever.?
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All of this is possible because of cheap mass storage.?
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Re: Archival data storage
On Thursday 05 December 2024 12:27:06 pm Donald H Locker via groups.io wrote:
On-site backups on most reliable current technology with off-site backup on a service's storage media. They KNOW how to maintain data forever: swapping storage devices as they age (instead of when they die); storing data on multiple spindles with error detection and correction; testing regularly for data consistency; etc.It's hard to put a cash value on "stuff" that I've collected, but one consideration is the time I have invested. Your comments make me think again about going to some kind of a RAID array, that server case I have sure would accomodate several more drives. It's more a matter of spending the money and setting it up than anything else And then putting some scripts in place to access the S.M.A.R.T. side of each of the drives as a matter of course. That's about the only practical solution I can see for me, here... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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Re: Archival data storage
On Thursday 05 December 2024 11:39:21 am wn4isx via groups.io wrote:
I warned him about the various ways hard files die, CD/DVD ROM rot, how audio tape can have the binder (glue) that holds the magnetic material (fancy rust) and become unusable.I bought a tape drive some years back, and have some tapes around somewhere or other. I was discouraged from using it because of the noise that it generates, I'd never seen anybody talk about the really annoying loud whine that it makes while running. I also have a couple of boxes of tapes, in two formats (large and small) but no drive to run the larger ones. Comments that I've seen here and there suggest that the drive belts contained within the cartridges might be a problem. I don't know. I've bought a 100-pack of writable CDs, still have some of those left, and a 50-pack of writable DVDs, ditto. Somebody just gave me some more of both of these. I use them occasionally but neither one is really practical for backing up a 4TB server drive. (...) Most of us don't give much thought to preservation of archival data but maybe we should.Yup. (...) NOTE: I've avoided Apple products and have no idea what magic key strokes he's describing...and I'm happy to remain ignorant.Ditto. I had one IIc some years back, gave it away. Had a PowerPC mac, scrapped it. There's a complete IIgs system out in the garage, it even has two sizes of floppy drive with it, I've never fired it up. I hear those have some nice sound capabilities. Several friends have contacted me over the last 20 years with I-Omega zip drives with "Data I have to recover!"Got one of those out in the garage along with some disks, and no inclination to connect it to anything. I have had CD-R/DVD-R fail and 1 early commercial CD music disk lose 2 tracks. I was a bit irritated but found a new CD and tossed the old one.I can't say that I've had that experience yet. It seems to be the drives that are a problem for me more often. Got boxes of those, too. I have a large "archive." [if such a mess of unorganized data can qualify as an archive.] I haven't lost a drive, yet. I'm in the process of pulling the most important data to new hard drives. Since I have several Exabytes of data...yea it's a lot of unfun.Ii have a fair pile of stuff too, though I wouldn't say it amounted to anything near that much. I'd call it semi-organized. :-) I did post a while back wondering why a bunch of the older hard drives I have in boxes won't show as connected when I hook them up with an external interface. You can (sometimes) hear the drive spin up, sometimes you get the impression that the drive is doing some kind of initialization, but the computer just doesn't see that there's a drive there, for some reason. I didn't get much response to that post wondering what it is that fails on those. I notice that recycling companies seem to put a bit more value on "hard drive circuit boards" than on other stuff, I'm not sure why... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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Re: Archival data storage
¿ªÔÆÌåÓýA contact of mine in the archive business recconed that computer tapes would need to be converted to a standard format (7 or 9 iso) (from DECTAPE and 12/6 track and other odd formats ... you cant find the hardware) and copied with a verify 2
or 3 yearly (think of the number of tapes produced by a big company per year!!)? CD's are a problem too. Hard drives have a limited number of stop/starts I believe. Add to that papertape, film, video and you have a nightmare. Dave
On 5 Dec 2024, at 16:39, "wn4isx via " <hotmail.com@groups.io target=_blank>[email protected]> wrote:
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Re: Archival data storage
¿ªÔÆÌåÓýOn-site backups on most reliable current technology with off-site backup on a service's storage media. They KNOW how to maintain data forever: swapping storage devices as they age (instead of when they die); storing data on multiple spindles with error detection and correction; testing regularly for data consistency; etc. If the data are valuable, it's worth the small cost of professional backups. Donald. On 12/5/24 11:39, wn4isx via groups.io
wrote:
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Re: Archival data storage
WoW,
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Makes me wonder if aluminium based role of film with holes much like paper tape of Pace-16 NS days (early 16 bit micro dev system)
would be a rather long term reliable means of storage - pretty much immune to most radiation, thermal and light issues
though keep it dry Or maybe with modern tech graphene tape - keep away from heat and oxidisers.
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Now to work on a package to tightly compress data and arrive at optimum thin aluminium tape laser punching drive...
Hey now I have a use for those used aluminium beer cans, a rotating assembly laser imprinting holes on em LoL |
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Archival data storage
wn4isx
A friend has a production company with an audio studio. He switched from reel to reel tape to hard files in the mid 1990s. ? He called me in panic yesterday when he couldn't access one of his original archival hard files. ? I went over and was able to "wake the drive" by tapping the hard file with the handle of a large screwdriver, I'd have used a plastic mallet if I'd had one. ? NOTE: Do not do this until every other trick has been tried! Some hard files have glass platters and I had to tap pretty damn hard and could easily have shattered glass platters. [How hard? Like driving a nail in concrete.] ? We were able to copy all the audio to a new drive but that raised a question... ? I've always said there are two types of hard files, those that have died and those that will. ? I warned him about the various ways hard files die, CD/DVD ROM rot, how audio tape can have the binder (glue) that holds the magnetic material (fancy rust) and become unusable. ? "Other then clay tablets with cuneiform, all media degrades over time." ? He also collects "tombstones". Not literally, he's a member of a local history group and they make paper tracings of the information on tombstones. ? I asked "How many are barely legible?" ? "Quite a few of the older ones." ? ? I have no idea what he's going to do, he's 78, well off financially and may decide to retire. That would be suboptimal for former clients but he is facing a nightmare in time alone to back up all the hard files. Since each client's data is on their hard file(s), I suggested he contact them and give them the hard files with the suggestion "Back this up today!" ? Most of us don't give much thought to preservation of archival data but maybe we should. ? Here are two links that look at the issue https://arstechnica.com/gadgets/2024/09/music-industrys-1990s-hard-drives-like-all-hdds-are-dying/ ? https://arstechnica.com/features/2005/02/hdfailure/ ? NOTE: I've avoided Apple products and have no idea what magic key strokes he's describing...and I'm happy to remain ignorant. ? Several friends have contacted me over the last 20 years with I-Omega zip drives with "Data I have to recover!" I wished them luck and told them I have zero experience with zip drives and intend to keep it that way. ? I have had CD-R/DVD-R fail and 1 early commercial CD music disk lose 2 tracks. I was a bit irritated but found a new CD and tossed the old one. ? I have a large "archive." [if such a mess of unorganized data can qualify as an archive.] I haven't lost a drive, yet. I'm in the process of pulling the most important data to new hard drives. Since I have several Exabytes of data...yea it's a lot of unfun. ? I inherited 3 NTSC digital video editing systems after helping upgrade a local production house upgrade to digital. Digital video editing requires very fast RAID hard files, older hard files that were perfect for NTSC won't work. Not needing any video editing systems, I salvaged the drives and sold the stripped carcasses. The 'unlimited' storage allowed me to save anything online I found the least bit interesting. I'm having a difficult time separating the wheat from the chaff. ? What to save and what to let nature take her course.... ? or just erase it all... ? |
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oscilations in my amplifier ruins my PLL
Hello , I have built a PLL system based on the following article.
I have designed the amplifier to have some input voltage current output behavior.
but in the lab I sat that when i plug the the input I get oscilations at the output.
what could cause the situation? 3d PDF Layout and lab photos are attached.
Thanks.?
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/g/electronics101/files/john233/layout_new_amp_updated3.pdf
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Re: 2 files uploaded
#file-notice
This Link is all Paul needs to get to the AliExpress Item: So, when you cut n paste a link and find "?" simply delete it and everything (Tracking Information) following it. It only takes a moment to delete the excess C.R.A.P. -- G.T. |
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Re: my new psu
i found the current sense resistors( 4x250 ohm 10w jobs),i swapped those tor a 62 ohm 50watt aluminium resistor i had lying around,now i get 2 amps max ok,0-60+ volts max out would be nice tho,its hard to see how this thing works due to the amount of wires from its transfo secondarys !. |
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Re: 2 files uploaded
#file-notice
¿ªÔÆÌåÓýFor those who care, everything (in this link) is tracking
information. Many (likely most) links can be truncated from the
'?' on without loss. I, personally, don't care to have all of my
web activity tracked, so I always try a link without the tracking
stuff; no need to give them more than they paid you for it. is more than sufficient to access the product. Donald. On 12/4/24 09:26, paul larner via
groups.io wrote:
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Re: my new psu
Probably not. Max voltage typically set by regulator itself, inconjunction with raw DC being supplied off transformer.
If you find that output isn't what it should be, look at rectifiers and filter circuitry between transformer and regulator input. In addition, look at heatsink on regulator (s). Excess ripple (leaky rectifier, cap) can cause ripple rejection to limit output of regulator(s). If heatsink is loose, or compound dried out, that can cause regulator to run hotter and possibly reduce output. For a higher voltage, at near same power, consider use of single ended or variable boost converter. ~SD |
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Re: Latching Relay Drivers
Looking at another latching relay based on a STC 15F104W micro that is low triggered. Reviews (@ Amazon) have mentioned tying a .1uF cap across connections for denounce. That got me to thinking.
My previous attempts were to debounce switch at vehicle interior rather than under the hood, where noise was prevalent from CAN and ignition. I had caps in place already on switched line already, but at the switch end. Completely overlooked that switched line acting as antenna due to high impedance of tri-state drivers when inactive. Gonna revisit the pre-made versions, and change switched lines to cat5 or 6. Perhaps added capacitance inside shield would be helpful? Heck, adding cap at micro input may eliminate need for drivers altogether. That would be nice. Also looking at another latch relay ("HiLetgo 2pcs 12V Single Bistable Self-Locking Relay Module") that apparently has a trigger input limit of 5vdc, relay is twelve, output contacts up to 250vac. Given propensity I have for USB, even under the hood, derived 5vdc should not be an issue should I decide to trigger high. Got an early Christmas gift w/ permission to open. Ecoflow Alternator Charger. Looks to basically be a nominal 12vdc input to 60v (max) boost converter that is bidirectional. Was given to me as compliment to the Delta 2 power stations I use. Would be very nice to implement a 150A contactor to switch power to that converter. ~SD |
Mike
Gooey