Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: leevc5 on May 10, 2016, 09:23:42 am
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When Hoffman ships kit parts they ship a bag of resistors that do not have values marked on them. How do I match the resistors to the values on the board layout and schematic? If someone has a link to a chart that shows the color code on the resistors and the value that code represents it would be a tremendous help.
Lee
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Click on the "resistors" link at the bottom of this page. Since you are not familiar with the color code it may be a good idea to verify values using an ohmmeter.
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And sooner or later, you'll have to learn the color code system.
Here's a resistor color code calculator: http://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-resistor-color-code-4-band (http://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-resistor-color-code-4-band)
But sometimes the colors are hard to read on certain resistors, due to the background color they use or the specific color of the band itself (or because you have some mild, undiagnosed color-blindness). You need a multimeter anyway to check voltages & such, so you might as well verify your interpreted color codes by measuring resistance with the meter.
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Even when you have the color code memorized like your phone # or the alphabet,
always measure your resistors with your meter before putting them in your circuit layout.
This will save you lots of trouble. :w2: :icon_biggrin:
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lol, for sure
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lol, for sure
Sounds like you've been there done that too, Shack. :l2:
Orange and Red seem to be frequently misinterpreted.
Some manufacturers Red looks rather Orange and vice versa.
Then it's easy enough to get distracted and just grab the wrong resistor.
I've been doing this long enough to know to follow that simple rule.
But whenever I get in a hurry, or just neglect to do it.
It always seems to bite me in the ass. :l2:
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Even when you have the color code memorized like your phone # or the alphabet,
always measure your resistors with your meter before putting them in your circuit layout.
This will save you lots of trouble. :w2: :icon_biggrin:
^this^
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Here some links that will help a lot !
http://www.hobby-hour.com/electronics/resistorcalculator.php (http://www.hobby-hour.com/electronics/resistorcalculator.php)
http://www.electronics2000.co.uk/calc/capacitor-code-calculator.php (http://www.electronics2000.co.uk/calc/capacitor-code-calculator.php)
http://www.justradios.com/uFnFpF.html (http://www.justradios.com/uFnFpF.html)
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Maybe y'all haven't seen it but Hoffman provides links to 4 band and 5 band resistor calculators right on the page that you buy his resistors.
Click on the "resistors" link at the bottom of this page.
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Maybe y'all haven't seen it but Hoffman provides links to 4 band and 5 band resistor calculators right on the page that you buy his resistors.
Click on the "resistors" link at the bottom of this page.
You can lead a horse to water, but you can't make him scan the catalog page...
4 Band Resistor Calculator (http://el34world.com/charts/resistor/4BandResistor.htm)
5 Band Resistor Calculator (http://el34world.com/charts/resistor/5BandResisitor.htm)
Even I overlooked them the first time.
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hard to read on certain resistors, due to the background color
as an aside, this problem came to light in the early *Chinese import days* for painting artists, The Chinese idea of blue (or most any color) and ours were nowhere close! there was a lot of back n forth, The Chinese are good at mimicking so; *here, make it look like this*, now my phthalo blue looks like it should!
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There is a saying that I cannot remember that helps remember resistor values. Worry not tho, if you do this for a couple of years you will remember them. In amps resistor values become redundant in a lot if instances.
I think the biggest mistake I make is with 4k7 and 47K. One part of my brain knows the difference, but another part doesn't remember and neither brain ever agrees. :laugh:
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I can only remember the non politically correct saying for those color code values. :l2:
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non politically correct
After the Navy taught me the *colorful* jingle, college had the *clean* version;
"Bad Boys Race Our Young Girls Behind Victory Garden Walls Get Some Now"
black brown red orange yellow green blue violet gray white, gold silver no color
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I have a hard time reading the bands on the metal films too. I sort the resistors into groups by color bands, then measure 1 out of each group. I prefer buying 10-packs though, that's even easier. ;)