Since parts can be obtained easily and cheaply through Internet mail order, it is easy to forget that buying electronic parts used to be a tedious process, and salvaged parts are usually used because they are what you own. Now, it may be a thing of the past to find the right resistor from the trash can TV to scrub the panel, but that is not all. [Ryan Flowers] Fortunately, he scored a box of old CB radios in a garage auction.
Looking for parts, he can use to make QRP amateur radio devices. In-depth study of aging electronic products is on our street!
One possibility for 27 MHz CB rigs is to convert them to the adjacent 10 m amateur band, but since these are AM rigs, this mode is rarely used by amateurs, so it is better to separate them. With the development of radio design, this is an interesting study because it reveals a completely analog design composed mainly of discrete components.
After carefully checking the photos, we found that Fairchild Semiconductor’s uA703 5-transistor IF amplifier chip is contained in a metal can, but this is as advanced as its technology. Unexpectedly, there are a large number of crystals instead of becoming a standard frequency synthesizer only a few years later.
He took away the case, switch and potentiometer, as well as the RF inductor and crystal from the PCB. Those tiny Toko inductors were once common, but now they are rare. If you like semiconductors in this era
, Where uA703
.
This is not nonsense at all, I have been doing it for 25 years... and still working hard!
Similarly, although it has been 22 years. I am 28 years old.
There are still boxes and boxes full of PCBs: old test equipment, medical equipment, PPE (gas detector), a bucket (Arm7 MCU) filled with a temperature recorder. A little bit of each :)
Recently, I bought some LM350 adjustable voltage regulators online. You used to buy them for about US$3.00, but I was shocked to find that they now cost about US$50.00 from Mouser, Jameco, etc.! WTF happened! Obviously, they must be in short supply and may not be manufactured anymore, so the price is too high!
Almost any part in the TO3 package you want is overpriced. They need too much work to put it in metal packaging.
Thanks for the information Roger! I don't know that fact. When I found out that the cheap, $2.00 LM350K TO3 is now on sale for $50.00, I damnably dropped the chair! I canned the bombed LM350K into cans and replaced them with TO-220 boxed LM317, because I don’t need much current because it is part of my self-made adjustable DC power supply, which I used for electroplating Built of silver. It can work perfectly with cheap and large quantity of LM317. Take care!
I have LM350 tube in TO220. I want to know if I can Ebay?
I suggest putting them on Ebay, you may be surprised by their supply!
Oh, wait, to220 is 2 dollars, and TO3 is 60 dollars. Get a good heat sink...
Yes, of course, I need TO3 package of LM350K. Because I don't need high current, I only use LM317 to solve it. I built an adjustable DC power supply for silver plating. It is flawless! I originally used LM350K to build it because that was what I had at the time, but when it became trivial, I found that I could replace it just by ordering another one. At that time I found that the price soared to $50.00! I found LM317 in the parts storage area, and instead, everything is fine and it works great! Take care brother!
LM350 is an ancient part. Use smaller regulators to drive large MOSFETs. You can now find that they have an on-resistance of 1 milliohm, which is approximately equal to the PCB trace.
Chances are, if you are using a large LM350, you don't have to worry about I*R falling.
For MOSFETs, what you are looking for is not the lowest Ron, but the Ron with the highest SOA rating. Low Ron devices are designed for direct on/off switching and do not need to have a large die to handle the heat required by linear circuits.
Calm children will use a switch to handle most of the voltage drop, and only use the LDO to maintain the final voltage of about 1V, so put the power supply in a much more usable TO220 or eqv package for control.
The LM350 crowd will not get caught up in complicated circuits, nor will they understand better parts. They will be better by sharing a bunch of old LM317 currents in TO220 or Boost current with external power transistors.
Thank you for providing tips on using LM317 and MOSFET! I am grateful! Yes, you can definitely choose other methods from the price of LM350K of $50.00! From this price, I suspect they are outdated. Thanks again!
Also here, I live in a very remote place and it is difficult to get parts. I have to wait, I don’t like waiting for 4-5 days each time. In addition, I like to save money. Therefore, when I was very young I started to disassemble electronic products (although not long ago), and then clean the parts, and sometimes I get something useful/cool. However, I have to buy some things. Can't I just find z80 and some EEPROM in the old microwave oven now?
This is the only way that I or anyone I know can afford electronics. When you can order soldering equipment specifically designed to remove items from the board, and often treat the board as a dispensable thing, there is almost no crash. Sometimes, if it has a particularly useful function, we will even put in more effort to save the whole or part of the circuit board. I have an LED controller, from a bad TV I have used to random LED things, this is a great simple controller, suitable for all kinds of weird configurations.
I need to do this because I don’t have money, but it helps or reflects my electronic knowledge.
The first few projects I tried failed. I copied the parts list and went to the store, unable to "buy it cheaply". They did not work.
I suspect that many of the reasons are my lack of soldering skills, but I know so little that I don’t know whether the pin arrangement is the same as that of the product, or whether the general-purpose transistor they sold to me is suitable.
The first thing that works is the code practice oscillator, the tge leads are just twisted together. But the parts came from extra boards I bought cheaply, and I cut the boards to remove the parts. Then there is a crystal oscillator.
The difference is that at that time I knew enough about alternatives, and my fear of "making mistakes" was reduced, so I could invest in it.
After that, I was always at a loss, although sometimes I had to buy some parts because I couldn't find them. I know that a few years later, other children in school became interested in this, and I told them to specify 1/2 watt resistors because they are most commonly used. Another person spent a lot of money on the HEP replacement series of operational amplifiers. When I pointed out the cheaper alternatives, he did say "I don't want to make mistakes."
I almost always look at the schematic and think about which parts I can replace or how to change it to fit my parts. It comes from understanding.
In the 70s, for me, most of them were old TVs, some of which were equipped with valves, although my best teenagers found were early varactors (obviously in later models). I still remember the stench of phenolic paper PCB when heated.
Oh yes, it's so memorable!
My mother hates that smell
My father used a 75W Weller gun model for desoldering to heat. This is a method my father used to make vacuum tube launchers in the 1950s. It is a method to release the phenolic aroma. If the bugs are spared, another method It is to pass the power of 4-5W through 1 / before understanding the power consumption, use the power of 2W. good time!
What is the smell of the old flux core? When I was repairing things from the 70s, since I was a kid playing with electronics, I immediately felt back in time. It is not leaded solder, because I also used it today (lead-free solder sucks), it is an old flux core, probably rosin.
My method is to use a Bernz-O-Matic blow gun and use pliers to pull out the components. This is too smelly to be done in the house, so it is mainly for outdoor summer activities. If there are precision components, of course I will use a soldering iron. My first good desktop tool is the Weller WCTPN soldering station, which works many times better than the Radio Shack pencil soldering iron. In addition, bite-sized and rolled cores are also useful.
The early 1970s was the heyday of eroding old electronic products. Many things are made of common parts, which are easily found in Signetics, Fairchild or National manuals. When I was in high school, I used to buy stack boards from Data General, Burroughs, Mohawk Data Sciences, etc. for free on Dayton Hamvention. I can still pull many parts from those boards in the parts cabinet, although I might throw away the DTL IC at this time.
Considering all application-specific and surface-mount parts, it is becoming more and more difficult to find parts that are easy to produce, although I recently found a Chinese iPod FM modulator at a discount store for $1. The parts are cheap. Hole frequency synthesizer chip that can be reused,
When I was a kid, I could purchase all kinds of cool surplus items through mail order, such as PCBs taken from obsolete computers. These parts I have used before, and also used in obsolete military aircraft and complete military radios. The brand new box spare parts.
Even in the late 1960s, there was still a large military surplus from the Second World War and the Korean War, perhaps due to the need for new weapons during the Vietnam War, which led to an oversupply of military stocks.
For example, I bought a brand new boxed compressed air-driven gyroscope from a World War II bomber (although I am not sure which one, but I think it is a B-17 bomber), it has almost none. It is a kind of precision mechanical jewelry.
This is the armaments I bought. I read that they went bankrupt in 1988:
Meshna Surplus Specials: "Our 84-page catalog is crowded with exotic, unusual electronic and optical equipment purchased from the government and other sources."
sad:
Remaining death
December 7, 2015
Satellite electronics on Vancouver's main streets in the 1980s
Oscilloscope and oscilloscope repair, chart recorder with excellent galvanometer for laser show.
At RP electronics, I got a 20,000 volt high-precision power supply. Something amazing. It can be set to 0.00v 20 20,000.99v! It has a huge vacuum tube rectifier. For my Plasma Scientific 2mw He Ne laser, this is too violent. When I have to slide from 15,000 to 2000, you should have seen sparks because the tube needs to trigger a spike, and the PS is not designed for this!
Both locations have a large number of wire-wound circuits from scrapped rack-mounted computer systems. I have never bought new winding supplies. I am actually engaged in the business of custom circuits. This does not require me to spend any money to build, except that the chips and components and a circuit board full of 12 inches x 6 inches are 2 dollars each!
good time.
Oh yeah. Certain other resins etc. seem to add to the familiar smell of analog electronic products in the 70s and early 80s. I still remember it myself.
I will reuse and rewind damaged ATX PSU and other SMPS transformers from time to time. I even make "transformer soup" to unlock the core. I reused some of the magnet wires in the large iron core PFC chokes included in the PSU...
Sometimes I reuse resistors and capacitors, and when I don’t have stock, I save all transistors, ICs, switches, many connectors, and all other valuable things...
I also removed the magnetism of the ATX PSU.
Lol @"transformer soup"... can I get that recipe?
Yes, you can!
You can start with a few transformers, re-soldering them, or use the mature transformers from the parts box. Tear off the tape holding the two core halves and use a sharp thin knife to cut or remove any visible resin holding it to the bobbin. Place the transformers in a small pot and pour enough water to cover them. Transformers should stand on their laps. Bring the pot to a boil, then simmer for 5-15 minutes. Use pliers or other tools to pick a transformer, place it on a dry cloth, and then pass half of the core through it. Try to separate them from the bobbin first, and then pull them apart. Gentle but firm, because it easily breaks the ferrite. If you can't separate them yet, put the transformer back in the pot and pick another one. If you remove half but the other one will not loosen, put the transformer back for a few minutes, then take it out, grasp the bobbin, and then use narrow pliers or other tools to pass the core through the center hole of the bobbin.
Transformer soup does not require seasoning. Service cold...
"Not suitable for microwave cooking"?
This was common in my university in the early nineties. They have donated pcb racks. We often clean the parts of the project.
I don't remember ever seeing the RS catalog. If we have to buy parts from Maplin or RadioShack, there will be no money, so less beer money...
I started to do this around 1959. Neighbors will give me their shabby TV and radio. By 1960, a neighbor paid me to repair his TV when I was 12 years old.
New parts are cheaper on many levels. To find the parts, you have to spend time looking for the right PCB, have time to get the parts from the circuit board, pray that the heat will not damage it, and ultimately you are not even sure whether the part is qualified or there are some potential failures after several years of aging . Original use.
Of course, for rare parts or rare/expensive parts, this makes sense, but otherwise it will waste time and you can use it better.
Not necessarily true. You can learn a lot by playing with old PCBs. In addition, not everyone can order components from China, so removal is their only option. I personally like to remove the components from the old trash. This is therapeutic and there is always some value in reusing/recycling things that would otherwise be discarded. It is not always necessary to absolutely optimize everything. Sometimes the game itself has value. But I want to treat everyone...
Large-scale disassembly and assembly with a spray gun is very fast, which may cause some stubborn parts to be injured or killed, and the grounding marks on the pins are obvious. I will sort and inspect the parts during disassembly, and I agree that the process of digging a box of wooden boards to find specific parts during the project is time-consuming and frustrating. A certain degree of random disassembly may also lead to potential failures, and such failures will not be immediately apparent. If there are important things, I will use new parts.
I collected old parts from TV and radio. They come in handy... part of it is sympathetic repair of old test equipment and professional music equipment (many 350v, 450v capacitors, ECC83 valves, high-power resistors, etc.), while the other part is dekatron and nixies. I have never been to amateur radio broadcasting-my head turned to audio and music equipment at a very young age, but I collected a lot from one person and only recently passed it. Now, I have multi-blade tuning caps, plug-in crystals, a large number of valves and power transistors, diodes, moving coil meters, coils, N-type connectors... I realize that one thing we missed with modern electronic technology is color , And various finishes, shapes and sizes. I have large resistive encoders, large polyester and polycarbonate capacitors, large bright electrolytic capacitors, TO3 power transistors, and highly polished housings (please show these transistors!). With such resources, to say the least, it becomes easier to find the right parts to repair an old electronic valve guitar amplifier.
Hi Nick! I have been working as an amateur radio operator for 43 years and I like to build my own equipment, especially RF power amplifiers. It sounds like your inherited library may contain some larger, transmitting or even smaller "fine-tuning" models. Air variable capacitor. I would love to know what you have, transmission tubes, variable air capacitors, roller inductors, etc.! Thank you very much for getting in touch with you! Since I don't have enough budget to buy new components, I have been struggling throughout my life with the radio, so I redistributed all my energy to me. Thank you! Best wishes!
Yes, addiction! When I was in my twenties, my Gran provided me with a working Philips AM/FM radio with six short-wave bands, and I couldn't help but disassemble its air gap tuning capacitor. Still regretted decades later.
We have all done stupid things, for example, when we were young and unwise, I also felt sorry. Lol!
Minivac 601, bc, you know, just sitting on that Bakelite panel like that, these DPDT relays are not accessible enough. FFS what am I thinking.
We all did it. Many historic radios died under my ten-year-old hand.
I learned something from it, which made me who I am now.
For those who are interested in electronic products, removing garbage electronic products is a useful effort. Worked in the field of industrial electronics for many years.
First of all, simply stripping off the therapeutic value of electronic components cannot be regarded as a way of relaxation. Disassembling the old electronic equipment and then unsoldering it from the PCB can maintain manual skills and require almost no effort. Then, some equipment or other equipment aroused your interest, and you searched on the Internet and found its data sheet, so you carefully extract it for future use. In strange situations, the entire project was found to be too interesting or potentially useful to be broken down into parts immediately, so it tried to repair it. Most of my home test equipment is purchased this way.
^^^Yes, this ^^^
Space forces me to stop grabbing roadside things like before, but disassembling some things and letting certain parts or subassemblies arouse my interest is still somewhat therapeutic and practical. I now have a lot of parts, enough to handle many repairs and projects, and I have almost everything on hand.
I have no rework skills or eyeballs to process today's surface mount products, and I do like the availability and low prices of all SBCs and other available modules today, so electronic removal may be an endangered art.
The thing to consider is that bed bugs like warm dark places. A roadside TV might be equipped with a six-legged traveler. Ah! Please check carefully before dragging it inside. Smoker-owned televisions emit unpleasant brown tobacco smoke residues on everything, especially the most unpopular CRT high-voltage lead. I have repaired a few TVs for my family and friends who smoke. It's hard to make smoker's residue smell. It's hard.
The problem with newly purchased components is their quality! All the components are from China, this is where we live, and most of the components are of very poor quality! The output transistor is the biggest problem! Totally underestimated, made in China! Therefore, I only use the original old quality components!
On Hackerspace, we did some heat gun tests on the old motherboard. Just shake the motherboard and the components will fall.
Oh, paint remover hot air gun == portable instant reflow device? Uh uh uh...
Make sure to get a heater with 2 heating settings (high and low). The lowest temperature will be around 250°C, you can use it carefully to reflow BGA etc. However, the more precise and controlled mechanical pencil is now only twice as expensive as the cheaper "paint stripper" heat gun.
In the first wave of lead-free soldering issues for laptop GPUs and chipsets, I used one of them for some operations. I actually have a hand-held drill that can insert the heat gun nicely into it. So I had it, and then I made a tin foil protective cover with a hole for the chip to be processed, and basically sat there for 10 minutes, and then waved around the IR thermometer like I knew what I was doing (Ok, I’m checking if the chip temperature is higher than 220C, and it’s not much higher than this.) The method is as effective as many other methods, giving you months of repair time, but only reassembly can really improve This method.
One of the most interesting things I learned a few years ago was to use a hot air gun to desolder parts. My recent attempts have left me with 5 (another messy) 62-pin edge card slots, and many more on the board. It does require some practice, so before trying the garbage game, please practice garbage first. Many times, these components will not fall out completely without any prying, but when it happens, it is quite satisfactory.
This is how to teach me how to solder by learning desoldering. By the time I started elsewhere, I was already very good at it. Oh, let's say this annoys people when I am outside school.
Before the "wheeled trash can," rubbish was scattered and piled up on the streets or placed in black bags. When I was a child, I used to ride a bicycle nearby on garbage collection days, then drag old TV sets and valve radios to my home, then disassemble and store them. I didn’t have the knowledge to use components at the time, but this might be how I was interested in electronics
I really thought this would be an article about miniaturization.
I have been doing less and less cleaning work, because these parts are getting smaller and smaller, and their use in hand-etched designs is also less and less, not to mention from more analog input solutions to digital switches. Mainly converted.
Even with all the appropriate tools, the time required to recover parts using SMD components and my personal conversion scrap rate are significantly higher than through-hole components. So yes, ordering a new product is more valuable than disposing of an old 0805 resistor, and when I reuse it, these spacers will fall off.
I'm used to soldering SOT-23 transistors (hint: rotate them 45 degrees when soldering to a 0.1 inch performance circuit board), but the most difficult part is determining the damn thing. Usually there are only 2 or 3 letters, some of which are dual diodes. However, if you are lucky, they will be in the list you can find.
I used to work in a place with several pick-and-place machines, and I think I did something right for a person, because when he vacuumed once every few months, he would leave random parts bags on my desk. There is nothing more crazy than trying to classify various components. I call the smallest particle "coarse sand", which is only slightly larger than the coarse sand. This is another form of removal, but it is still interesting. I sorted out a few dime SOT-23 transistors. I tried to make a project with some people. Real life prevents me from completing the work, but I do understand that I can solder SOT-23 by hand.
In the late 1970s, in order to get rid of cheap surplus boards for ICs, I found it easier to use propane torches. In this way, the parts can be removed within a few seconds, thereby minimizing the heat of the chip, but it can well damage the PCB. If they look useful, I still free them from the exhaust gas. High quality (low ESR) caps are expensive. Also, if a piece of equipment has a nice smooth action toggle switch, then I can’t throw it away! If it’s an iPhone, I just run the coaster app on it and put it on the coffee table.
I collected all kinds of old mobile phones from that thrift store. (After more than a month of lock-in, I am really happy.) Next week, I will introduce them to see if they can be used as a camera for making youtube videos to record projects. Basically set them to a fixed angle, start rotating them, and then copy the video and edit it when finished. I hope at least one or two of them are useful.
In Los Angeles, we are lucky to have several "electronic surplus" sockets, which are already filled with components that have been separated. I admit that this eliminates the trouble of destroying discarded or idle "gadgets". If this epidemic disappears, TRW Electronics/Ham Radio Exchange Conference will resume.
The surplus shrank severely elsewhere. Cali may be its last place to survive in North America.
I am currently mourning the exchange meeting I did not go to this weekend.
Indeed, the surplus is disappearing. Not long ago, a local aircraft manufacturer ran a "surplus" building, and it was a pleasure to select specialized tools and exotic materials with ease. Who knows, it might be used in one day. For now, the best local (Los Angeles County) is Cal Aero Supply at 13840 Paramount Blvd, Paramount, California. (Google it) They sell tools in pounds sterling. (Drills, taps, etc.) Screws, bolts, nuts, in pounds, yes, some stocks are typical "port freight" items, but hovering in the rear for real enjoyment.
As for the surplus of electronic equipment, please go north to the valley. All Electronics, 14928 Oxnard St
Van Nuys, California 91411
Yes from
several times. I don't think they will put anything less than 20 items on the website, or list really obscure things, so the actual location might be more interesting.
Yes, it must be visited. It is hard to believe the available inventory levels.
5 years ago, (I spent my whole life in a retail store), I forced my grandson to visit all the surplus stores in Los Angeles and Orange County. It took a whole day, but he was surprised by the appearance of "Stuff".
He used this information to support his college courses, where he was building "cube satellites" and 3D printed rocket engines, and now he has dropped out of school and repaired computers on cruise ships and submarines. In terms of swaps, TRW is the grandfather of everyone. But, like everything, it is slowing down. Now it is waiting for the virus to stop. (
) The "cool" product I bought last time was the World War II high-speed 35mm high-speed gun camera in the original box. (Shhh, don't tell my wife) I doubt I will try to make it into a lamp or something. Maybe the background object of my video podcast. Last year TRW offered two missile gyroscopes for sale, but even though they were super cool, I passed them.
God, save any air variable caps you encounter! I think they are not difficult to make, and most people will not be useful to them, but I don't think they make them the same as before!
High-quality bottle caps are actually still available, but even Chinese caps are easily sold for $10-15-so saving them is worth it.
But up to now, the equipment with variable air caps has also begun to have a long history.
I thought the article cited by tye looks very fictitious. He found a set of circuit breakers, but was excited about common parts. This is something I noticed elsewhere, anyone can post it, but it does not mean the best information.
I have posted a long reply there, suggesting something better that can be learned, but I also suggest that for some esoteric parts, it is best to keep them intact, because the circuit board will provide the data of these parts and how to use them they. In addition, sometimes when using electronic parts, you may need the original circuit block, so it is best to also cut off this area of the circuit board (if it is not a separate module).
This is a good comment.
Without the rest of the circuit, it will be difficult to separate the oscillator coil from the RF tuning coil and everything else.
I once took apart a radio and did not restore it, but carefully marked the names of all the different coils in the circuit. Therefore, I have [radio model, component name] IF coil 452KHz attached to the jar.
Of course, you can put the coil in the oscillator circuit and see what its span is, but this is a lot of extra work. Due to the presence of radio frequency shields, it is difficult to check them with a micrometer.
I haven't really had a "harvest" meeting in a while. When I was a kid, AM radio seemed very rich, so my first project had many points. Then in the millennium or so, I had a little understanding of VCR, the output and variety looked good, and in the end it did not deal with too much awkward garbage like CRT. Then we encountered the disaster of capacitors. I used a large number of motherboards as organ donors for other motherboards. But, last time, I tend to choose them according to your needs.
However, a few times, I had a "part" thing, and then I found it interesting in itself. There is some kind of S-100 board. Galaga arcade board. I haven't found a motherboard with 8088, please continue to try if you want to peel it off or try to run it somehow.
For me, the motherboard is an important source of surface moutn MOSFETs, some are 12amp or higher, usually 3 to 5
In the 1990s, I bought a small hanging basket with Pcop-11 board (single width, with two edge connectors) in a thrift store. I think one of them is a UART board, but there is nothing more special than a CPU or memory board, otherwise I might care more.
In the early 1990s, when I was a teenager, I encountered an adventure story. My grandfather’s microwave oven is broken-a micro switch somewhere is malfunctioning. It sat in our basement for a while. A few years later, a colleague of my father brought a broken Amiga 500 and several Epyx 500XJ joysticks. He started looking for parts, then kept a low profile, and found that the 500XJ used the same micro switch as the microwave. I took that microwave oven to college... I remember telling my roommate this story. One of them said: "This shift must make 1988 "Switch Journal" an editor's choice."
I changed the door switch 3 times on the old (now retired) microwave oven.
Alternatives come from various donors. The other switches of the door did not malfunction.
I do this for work (automotive electrician), such as repairing electronic organs, etc., sometimes driving chips/FETs or anything that is difficult to purchase with reasonable quality. Therefore, I try to keep stocks of some good donors of common boards. Fortunately, most manufacturers usually either dice the internal parts of their ECUs or throw the dice on potentially junk parts from China. . I am sure that the repair locations of mobile phones/laptops/game consoles are the same, there are many proprietary things.
All the things I used to do when I was a kid (old radio, TV, etc.) were caused by getting parts, because I can’t afford new parts for the project, I have to say that surface mount things are easier to rebuild once I get the know-how use.
About ten years ago, I reinstalled the ECU on Suzuki.
*Clear...
I stopped doing this a few years ago and spent hours rooting in useless outdated consumer trash to find a 7-cent transistor,
It's the same for me. Of course, if you happen to need some rare or hard-to-find components, and happen to need these scraps, but apart from "meh", my position is the same.
My problem is to know when not to salvage what, let it go. "I will use it someday" quickly became "I must get rid of all this nonsense".
My neighbor who grew up had a "garbage day" every year. My father went shopping with me. The amazing things that people throw out only need some adjustments here or there, otherwise we peeled it off and used it for test tubes, spent a few hours on the bench for test tubes, and thus inherited the humidor, except for me Indeed throw away all 1B3. I bought my first recording device in this way before I was in the second grade. It was a well-functioning Webster recorder with extra spools. The old garrard and BSR turntables were once a complete wooden stereo speaker, and everything is still inside. Speaker Jason, this is interesting.
I cannot tell you how many items have been thrown away because of the thermal fuse that I replaced and sold to make a profit. At the age of 12, my mother bought me a set of Encyclopedia of Popular Mechanics. Since then, all my knowledge of electromechanics has been popularized. I got a degree in mechanical engineering, but I have always been rooted in electronics. I should have been a double major. Today I am still looking for food, and my wife thinks I am addicted. I only accept useful things. true!
Everyone should have 3 sets, namely 50s version, 60s version and 70s version. Skip the 80s (eventually?), this was a problem with magazines at the time, it was a "how do we spend money" publication, not how to do things. There are also popular scientific and practical handymen worth mentioning.
I still have some boxes, they were cleaned in the 50s and 60s. Does anyone need a selenium rectifier?
Most things are no longer worthy of scrap, but every month I will dispose of the rubbish at our local garbage collection office. There must be something worth scrapping here. There, I opened up the entire through-hole life cycle monitor in the 90s (a lot of electro-pneumatic parts, expensive instrument lights, to3 volt reference voltage, etc.), several desktop power supplies, and a hp200a Audio oscillators, and many other things that can be fixed or equipped with high-end mysterious parts.
Well, I believe that we are at a time when parts one by one disappear from our eyes due to miniaturization. PCB space is left to store more and more dedicated ICs. These ICs are more difficult to inspect and reuse. It is difficult to find a home in another device.
Looking to the future, I believe there is "thing" only in the nonsense of the entity level. From a weird point of view, today's through hole is a wooden board. In this direction, the new trend of circularity has some very interesting concepts. With a lot of engineering work and social interest, these concepts can lead to more standardized, separable, repairable and reusable equipment. But the reality on the ground seems to be different.
There are "11m" CBs with SSB in the United States...Despite the common noise in this frequency band, I even made an incredible 1,000-mile contact with a back during the solar cycle in the 90s. Changing the IF of one of these units is not much different from the more common-mode CB-at least as far as the older model is concerned. Modern units use chip-based oscillators, which are more difficult to modify in most cases. The real problem is that in the past few decades, the 10m band of DX has died out. This is due to long-term sunless conditions, which are extremely active during this period.
Haha nope. not dead. Whenever I need a switch or similar thing like a prototype or a singular project that doesn't require ten things, I often use a hoarded parts warehouse.
I cleaned an ISA debug board from an old computer. It has 5 TIL311 and some other goodies. I also found 33 am27c4096 EPROMs during dumpsterdiving.
Like a treasure hunt
After taking it out of the box, I have started storing the PCB. They take up less space and it is easier to identify the parts if you have the entire circuit board.
I did shoot many parts on some old telecommunications boards with a propane torch by tapping the end of the board hard to loosen the parts. It works, but it's not as good as I wanted. For this, I do need to make bumpers to clamp on the board.
DIP is the challenge of effective removal. I am still looking for a better way. I am very disappointed with the desoldering gun. The remaining solder is enough to keep the material in place.
Yes, part of my comment on the original site was to keep the board intact.
On the other hand, once I started to carry some tools to strip the e-waste, I saw it waiting for a garbage truck. It is easier to grab a power transformer or variable capacitor than to drag the whole thing home. Or turn on the computer to get memory, hard drives or exotic peripheral boards.
Sadly, I see less and less e-waste in the dump or garage. I think this will be waste collection. As someone once suggested, this collection will ensure that people buy new products.
Before I waste things (VCR, DVD, etc.), I take them apart. Then, I only need to pay a higher return fee for the circuit board itself and a lower rate for the rest of the circuit boards. They did not charge me for direct entry into the metal bin.
I have always wanted to make a tool for DIP. I can see something like two miniature claw hammers, used for the curved part of the claw hammers, connecting those claw hammers to two arms and a handle, so when you push it, they roll together and pull up. Or just a better chip puller. I used the ISA slot punching mechanism to become a spring clamp type, which can take out some RAM chips at a time, but its size is just right, so it is not very useful for anything else. Like some SOJs, it won't help if the damn thing is abused on the board.
However, it is best to use a suction cup to fix it end by pin. It is usually best to use the tip of the soldering iron from the side and align the suction cup exactly to the top of the pin before triggering. Then they will usually become very clean. If not, row down and "flat" each with iron, which will break the connection. If your hole is too tight with large rivets, it seems too narrow to suck in... Then sometimes the only way is to pull the chip upwards about a millimeter at a time until it moves the chip upwards. Come out immediately. Heat, lift one side, heat the other side, lift, repeat. When one of my techniques is worn with a 30W iron soldering iron, I cut it off, then cut it open, and cut a one-inch-wide triangular copper sheet into it, then drilled a small hole, and then fixed it with a small bolt it. Now, it is a pin heater/slicer/bulldozer for some awkward things. Either heat a row of pins at a time, lift one side of the SOJ at a time, or push away some small Rs and Cs.
The quick chip test has helped me remove the bad IC several times, but please clean the circuit board thoroughly before trying to install a replacement product.
The county’s state parks have 1920s farms, houses, and outbuildings. We provide piano players, which are typical digital music players today. My boss restored the finish of the battery radio and grill cloth in the front hall. It lacks knobs, molded Moderne style. The monkey ward has been around for a while. I looked at a box of old radio and TV knobs with a preserved treasure in it that matched the missing knob. Once on the broadcast, okay! Back to Indiana again.
Don't ignore the possibility of using existing knobs to make silicone or Bondo molds and casting epoxy replicas for missing knobs.
As seen on Hackaday(TM) servers a few years ago.
My favorite is the Marantz tube power amplifier front panel I found on the side of the road-nothing but a thick aluminum front panel.
I built a modular (22 panels) synthesizer with most of the cleaned parts. I have to buy some potentiometers, jacks and switches, and some more specialized ICs that I can't find in radios, etc.
When I was a kid in the 1950s, there was a radio/television repair shop about half a mile from my home. They have a shed where they throw away equipment that the customer does not want to repair or equipment that they have repaired but the customer does not pick up. Several times a year, they will let our children fill the carriage with what we want. What happiness do we have! I remember that Zenith Transoceanic I found at the time was still working. I tasted that shortwave radio for the first time. Later, I worked at Zenith as a TV engineering technology for a period of time.
Finding the Zenith Transoceanic SW suit is very cool! I have been a licensed amateur radio operator for 43 years and I have been working since I was 6 years old, listening to shortwave radio in the heyday! I like this hobby and built my own equipment. It is very educational at all levels, including geography and world culture!
interesting. Last year I received a message from a child who pulled a 22-year-old agricultural control box from the trash can. At that time I put the email address on the S/S layer. At that time, my (competent) partner insisted on clearing the IC ID. Therefore, the child wants to know the content on the PCB and the purpose of the box. And his roommate wanted a part of it. After replacing the lid and transistor, he made the box work normally.
We have been talking for a while, and we have recruited another person from the dark side. When he returns to school, he will switch to EE major. Everyone cheered Lord Vader.
Or as they said recently.
B ^)
I use a bunch of stereo speakers from the 70s and 80s. Usually used as an endless supply of replacement covers. Suitable for newer Jankier electronic products.
The board must be the correct year.
Too early: They have old useless DIP parts on double-sided PCBs. It is difficult to remove and not worth the effort. I have 20 tubes of various unused parts and trash cans. I haven't touched it in the past 20 years, and it feels like there is no tomorrow. Since there are only a few stitches, the simulant is easier to delete.
Just right: SMT parts are easy to desolder with hot air tools. The boards are still made of soft candy, so they can still be used.
It's too late: a large SoC with only one function. They are not useful for anything other than design purposes. BGA or other difficult-to-use packages that require multilayer boards. Mainly choose the passive.
Goldilocks Dilemma
My problem is that you want to kill the original work, and it is difficult for me to do so. A long time ago, I had a bunch of Unix machines that could hold 300 MB SCSI drives, the memory of which could be modified to fit a PC, and each machine was 20 megabytes. I sell them at a price lower than the value of the drive, just because I cannot take them apart by myself. They still work. I do have a few boxes of rubbish boards. Although these items are indeed made of hoses, I still make scarves. I find that few surface mount parts are much more difficult.
Write here. This used to be a problem for me, but I overcame it. I woke up one day and said, "This thing gathers dust and is of no use to anyone, or I can take it apart, and at least I am very happy to take it apart." "But it's retro!" Someone said. Yes, there are? Useless is useless, no matter how old it is. The 23-channel CB is neat, but as useless as the CB. When was the last time someone had fun with one of these radios? A long, long time. I have had more fun from it than anyone has imagined in the past 25 years. Now *that* is valuable, and make them valuable.
In fact, this reminds me of some things that came to my mind when thinking about this topic the other day:
For historians and archaeologists, sentimentality makes sense. I am neither
what are you saying? That is our daily bread in Africa. I have been doing it for 35 years. Professor of physics.
Old industrial gears = a source of expensive high-value parts, otherwise expensive or not available at all!
Wow! Check out all these replies. And I thought I was the only one who likes to tear garbage into pieces. I have nothing to add. It's nice to see other people evolve like me.
This is the way of the past, and it will be the way of the future. Resources are limited, and learning by connecting different source components is the best form of learning. And save money...
A few weeks ago, I assembled an electric guitar amplifier. The pickup is a solenoid. Random stereo system speakers. Printer power supply. Switch to vintage wine from the 1950s, made in the US :) The jars are newer. Knob on old test equipment. The audio transformer is actually a 120/24 V power transformer... I used a new transistor, but this is optional. There are hundreds of old and new things around me.
The end is almost here! Prepare... :)
I have some boxes with old through-hole assembly boards instead of removing all parts. Now, I have a deal with a local recycling station: I can take any mechanical/electrical equipment-they return some repaired equipment (free of charge), and I have an unlimited supply of parts. 20 LCD TVs must have been collected by now. Best find: Almost brand new washing machine, showing error code. The error is: clean the filter. And coffee machine with error. Use vinegar and preservatives for a few cycles!
The good things that fools throw away are amazing! I have never bought a new TV, but over the years, I have collected many great TVs from the garbage dump on the roadside and repaired them at very little cost. The latest TV I'm currently using with great results is a 50-inch LED TV with an excellent thin screen! I don't even need to fix it! The reason that guy threw it out was because the rhythmic "ticking" sound from the center speaker was almost below the human hearing level! I don’t even have to worry about installing it correctly, just disconnect the speakers! The left and right stereo speakers are working properly, enough to meet my requirements! Lol!
* scavEnging!
Are you sure we are not writing sc-Avenging?
The best cleaning unit I just found is a 512 Canon printer. The sum of the parts I cleaned greatly exceeded the price of this old printer. 30 micro switches, 6 small stepper motors, 150 small screws, a small matching kit of 22 springs, 26 plastic gears with different transmission ratios, many ribbon wires and connectors and everything I can recover from the board Electronic parts. And I can send all plastic parts to a recycling center instead of landfill. These are part of the honey scavenger hole. Never give up all these parts. The main finding...
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