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In article <a919cc1me83i0bm0lbdv5ebbrfrubikp9e@4ax.com>,
oldschool@tubes.com says...
Now that I know what the initials mean, I know what these are. I have
seen them. As far as I'm concerned, they are the devices which cant not
be repaired, unless the whole boards are replaced. Yes, i am sure they
can be repaired, but it wont be me working on them. Poor eyesite is just
part of the reason. Thats why I prefer the old tube stuff to work on, or
at least the early transistorized stuff on single layer boards, which
contain parts that can be touched without using a tweezers....
For me, IC chips and SMDs took the fun out of electronics as a hobby...
(Not that they are bad, but they are not for the home workshop, they are
made for robots in factories that create them, and people who have very
expensive test gear to trace them). I still recall trying to unsolder
some IC chips, and ruining them every time. Then spending days or weeks
trying to locate replacement parts, because they are factory numbers
that cant just simply be purchased.
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.
According to this chart (and others like it), One Ohm is black -black -
black...
In article <ihi8ccl5742kl5ca5me3d21fou4h5erbv6@4ax.com>,
oldschool@tubes.com says...
Here we go with those initials "SMD" again. I keep seeing that in posts
on here and elsewhere. So I better ask...
What the heck does SMD mean?
SMD is surface mounted device. For resistors and capacitors they are
usually small and flat. They are usually silver colored on the ends.
That is there you solder them to the circuit board. The ICs will often
have what seems like very short leads. They lay flat on the circuit
board also.
Check out this youtube video as to what they are and ways to work with
them. For very much work it helps to have a good 10 to 20 power
stereo microscope.
I believe you are reading that chart wrong.
I have some resistors and checked them out. One is a brown black gold
and is 1 ohm. Another is brown black silver and is .1 ohms. That is
measured with a Fluke 87 VOM.
I don't know for sure, but maybe the resistors do not start off with a
black band. Don't have any loose resistors to check, but many on
circuit boards are a solid color with a black band in the middle.
Yes, after a while, you aren't so much "decoding" but just recognize theIn article <b529cc5scqie1d5qsj10tqk7rfh42ik7jd@4ax.com>,
oldschool@tubes.com says...
I never had any problem with the color codes in the old days, because I
dont recall ever running into any resistors less than 10 ohms on the old
tube gear. It's just these small value ones that are tricky.
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.
On Sat, 11 Mar 2017 13:13:56 -0600, oldschool@tubes.com wrote:
According to this chart (and others like it), One Ohm is black -black -
black...
No, that is not correct. Notice that the fourth band says
"multiplier".
The chart shows four bands plus tolerance, which means three digits
plus a multiplier, plus tolerance.
You multiply the first three bands with the multiplier value. Since
the three first bands in your example are all zero, you must multiply
zero by one ohm, which is still zero.
An easy way to remember how the multiplier band works, is to think of
it as "number of zeroes".
Now that I know what the initials mean, I know what these are. I have
seen them. As far as I'm concerned, they are the devices which cant not
be repaired, unless the whole boards are replaced. Yes, i am sure they
can be repaired, but it wont be me working on them. Poor eyesite is just
part of the reason. Thats why I prefer the old tube stuff to work on, or
at least the early transistorized stuff on single layer boards, which
contain parts that can be touched without using a tweezers....
For me, IC chips and SMDs took the fun out of electronics as a hobby...
(Not that they are bad, but they are not for the home workshop, they are
made for robots in factories that create them, and people who have very
expensive test gear to trace them). I still recall trying to unsolder
some IC chips, and ruining them every time. Then spending days or weeks
trying to locate replacement parts, because they are factory numbers
that cant just simply be purchased.
I never had any problem with the color codes in the old days, because I
dont recall ever running into any resistors less than 10 ohms on the old
tube gear. It's just these small value ones that are tricky.
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.
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.
In article <a919cc1me83i0bm0lbdv5ebbrfrubikp9e@4ax.com>,
oldschool@tubes.com says...
Now that I know what the initials mean, I know what these are. I have
seen them. As far as I'm concerned, they are the devices which cant not
be repaired, unless the whole boards are replaced. Yes, i am sure they
can be repaired, but it wont be me working on them. Poor eyesite is just
part of the reason. Thats why I prefer the old tube stuff to work on, or
at least the early transistorized stuff on single layer boards, which
contain parts that can be touched without using a tweezers....
For me, IC chips and SMDs took the fun out of electronics as a hobby...
(Not that they are bad, but they are not for the home workshop, they are
made for robots in factories that create them, and people who have very
expensive test gear to trace them). I still recall trying to unsolder
some IC chips, and ruining them every time. Then spending days or weeks
trying to locate replacement parts, because they are factory numbers
that cant just simply be purchased.
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.
In article <b529cc5scqie1d5qsj10tqk7rfh42ik7jd@4ax.com>,
oldschool@tubes.com says...
I never had any problem with the color codes in the old days, because I
dont recall ever running into any resistors less than 10 ohms on the old
tube gear. It's just these small value ones that are tricky.
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.
There are some sellers on ebay who are selling assorted resistors in
quantity. Some of them claim these assortments contain 0 ohm
resistors.... WTF. Wouldn't that be a piece of wire?
What would be the point of that?
How would you even color code it?
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.
I think that accounts for why in hobby circles, their attraction wasIn article <p7bacclrj1eke4biu9jg5ekkcqsctep33h@4ax.com>,
oldschool@tubes.com says...
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.
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!
On 10/03/2017 13:30, oldschool@tubes.com wrote:
There are some sellers on ebay who are selling assorted resistors in
quantity. Some of them claim these assortments contain 0 ohm
resistors.... WTF. Wouldn't that be a piece of wire?
What would be the point of that?
How would you even color code it?
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.
In article <MPG.332e6d0ab85d4d1f989893@news.east.earthlink.net>,
rmowery28146@earthlink.net says...
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.
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.
Now that I know what the initials mean, I know what these are. I have
seen them. As far as I'm concerned, they are the devices which can't > not be repaired, unless the whole boards are replaced. Yes, I am sure > they can be repaired, but it wont be me working on them. Poor
eyesight is just part of the reason. That's why I prefer the old tube stuff to work on, or at least the early transistorized stuff on single
layer boards, which contain parts that can be touched without using a
tweezers....
For me, IC chips and SMDs took the fun out of electronics as a
hobby... (Not that they are bad, but they are not for the home
workshop, they are made for robots in factories that create them, and
people who have very expensive test gear to trace them). I still
recall trying to unsolder some IC chips, and ruining them every time.
Then spending days or weeks trying to locate replacement parts,
because they are factory numbers that can't just simply be purchased.
Please note that there are SMD versions of these as well. They will be
marked with a single zero(0).
You will often see these used to jump a trace in SMD applications.
On Saturday, March 11, 2017 at 8:34:48 PM UTC-5, Ralph Mowery wrote:
In article <a919cc1me83i0bm0lbdv5ebbrfrubikp9e@4ax.com>,
oldschool@tubes.com says...
Now that I know what the initials mean, I know what these are. I have
seen them. As far as I'm concerned, they are the devices which cant not
be repaired, unless the whole boards are replaced. Yes, i am sure they
can be repaired, but it wont be me working on them. Poor eyesite is
just
part of the reason. Thats why I prefer the old tube stuff to work on,
or
at least the early transistorized stuff on single layer boards, which
contain parts that can be touched without using a tweezers....
For me, IC chips and SMDs took the fun out of electronics as a hobby...
(Not that they are bad, but they are not for the home workshop, they
are
made for robots in factories that create them, and people who have very
expensive test gear to trace them). I still recall trying to unsolder
some IC chips, and ruining them every time. Then spending days or weeks
trying to locate replacement parts, because they are factory numbers
that cant just simply be purchased.
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.
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.