0 (ZERO) Ohm Resistors (WTF)........

While it does say multiplier, it is not the traditional 'multiply any number by zero and you get zero. It is more like the number of zeros to put at the end. That is why a red red black is 22 ohms and not zero ohms.

I am 67 and just started working with the SMD about 2 years ago. If your hands do not shake too much it is easy if you have the right tools. For the hobby people like me that does not want to spend too much, it takes about 300 to 350 to really get the right equipment. A good microscope can be bought for about $ 190. A hot air and small soldering iron combination is about $ 60. Then a few tweezers, very fine solder,liquid solder, liquid flux and some kapton tape round up most of the other items you need. Get some old computer boards and practice for several days and it will be easy. Be sure to look on youtube for some videos to see how the pros do it. They make it look very easy.

One easy way to replace the ICs is to cut the legs from the plastic case and remove them a pin at a time. Don't try to save them.

The odd ball factory numbers are something else. There should be some kind of rule they can not use house numbered parts unless it is especially made for that piece of equipment and not used by anyother company. Some companies even sanded off all the numbers on the parts.

For the standard resistors it was almost second nature for me to just look at a resistor and call out the value. There were only a few values used most of the time, and then the last band for the multiplier. Especially when most were the 10 % type.

Probably getting a bit off topic, but when removing SMD parts, I use ChipQuik. Check it out, it works great and the removed part can be used again if it is not the problem.

Dan

Yes, after a while, you aren't so much "decoding" but just recognize the value connected to the coding. Three red stripes? Of course that's 2200. I can't even tell you what 4.7K is, but I'd know one when I saw it.

SO much effort put into mnemonics to remember the color code and cardboard decoder rings, when all you have to do is spend some time looking at resistors, like when you are sorting them out.

Michael

The multiplier is ten to the power of the colour. Any number to the power of zero is one. Hence the result you cite.

Mike.

cardboard

After I had spent a while scrabbling through my Dad's random collection of resistors looking for an acceptable value, I got a strong urge to pick out any one and re-paint the colours...

Mike.

The old tube stuff was made to be repaired. You'd unplug a tube and stick it in a tester. If it was not the tubes, you'd begin checking the passive parts.

With ICs, you cant unplug them or test them. They DO make sockets for them, but they are never used on consumer products, and if they could be unplugged, there are no testers, at least not a general purpose tester for all ICs. I suppose companies have testers for specific ICs that they use. Cutting the leads on the ICs is a good idea if you know they need to be replaced, but much of the time you want to remove them to test them (as best as possible) out of the circuit.

At least single transistors could be unsoldered and tested. When I used them for some projects that I built, I always put them in sockets.

Things just are not made to be repaired these days. And like you said, the part numbers are often "house numbers", which makes it impossible to fix the stuff. I guess thats why computers are made wih boards that are just unplugged and replaced. The boards themselves are the components, but often times the boards cost more than the whole device.

It's been nearly 40 years since I did any serious work on electronics. But I still remembered the color codes, many of the common resistor sizes, common cap sizes, and the numbers on the most used tubes. I dont think I ever used a resistor below 10 ohms, except the wirewound types, such as the old huge 8 ohm WW ones that I used to use for speaker loads. I think they were rated at 100 watts. I saved a lot of that stuff, but much of it has vanished over the years.

The really funny thing is you can buy them in 1% and 5% tolerance. I'm betting that none of them are within tolerance though.

There's also the problem that at the speeds stuff works at these days, the extra spacing is electrically significant.

I remember playing with a tunnel diode in the 1960s when they were commercially available and they were quite difficult to stop oscillating!

Mike.

I think that accounts for why in hobby circles, their attraction was mostly as an oscillator. "WIreless mics", QRP transmitters on the amateur six metre band, oscillator/mixer in various receiver circuits. Offhand, I can't remember much of their use as amplifiers in hobby circles.

Michael

Bien vu !!

SMD is easier to work with than old point to point wired chassis. I am in my mid 60s, and I have had poor eyesight all my life. I worked with SMD boards daily at Microdyne. I now have a nice B&L Stereozoom 4 boom microscope for my projects now that I'm retired. I purchased an adapter to be able to record video from the microscope, so that I can post video of the techniques I use.

You need the right tools and some practice to work with the small parts. I routinely removed and replaced 288 pin ICs without damaging the PCB or to IC.

ASIC (Application Specific Integrated Circuits) are what you referred to as "can't just simply be purchased". They only make sense for products built by the millions, or for unlimited budget high end industrial electronics.

A lot of what you think are unavailable is because you don't know actual part numbers, VS what they have room to mare a component with.

They occasionally double as test points on SMD boards.

I use a modeller's pencil blowtorch to heat the bare side of the board - when any SMD part moves; I tap the edge of the board on the bench and a whole pile of parts just fall off.

The hobby magazines of that era were full of TD bugs.

I've never seen any with more than 1 black band round the middle.