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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Help reading 5-band resistor?
I have a resistor in an analog VOM meter that I suspect is bad. It is
exclusive to the 1x ohm scale, which is now reading as if it were the 1000x ohm scale. The color bands are as follows: Red Grey Violet Gold Red There is a larger space between the gold and red bands than between any other adjacent bands. .... and it is of this type: http://upload.wikimedia.org/wikipedi..._Resistors.jpg I read this as 280,000,000 ohms with 5% tolerance and 50 ppm temperature coefficient, but when I use a digital meter to read the resistance it comes in at 270,000 ohms. I noticed a small hairline crack in this resistor and when I poked it with a pin a small flake of the outer coating fell off. 280,000,000 ohms seems like an awfully large value to me. Could this be a correct reading? Thanks |
#2
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Help reading 5-band resistor?
On Sun, 24 May 2009 10:41:43 -0700, Readily Visible
wrote: I have a resistor in an analog VOM meter that I suspect is bad. It is exclusive to the 1x ohm scale, which is now reading as if it were the 1000x ohm scale. The color bands are as follows: Red Grey Violet Gold Red 287 / 10 (e.g. 28.7) at 2% tolerance. -- Rich Webb Norfolk, VA |
#3
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Help reading 5-band resistor?
Readily Visible wrote:
I have a resistor in an analog VOM meter that I suspect is bad. It is exclusive to the 1x ohm scale, which is now reading as if it were the 1000x ohm scale. The color bands are as follows: Red 2 Grey 8 Violet 7 Gold 5% Red ? (I never learned this) The trick I learned was bad(black 0 boys (brown 1), rape (red 2) our (orange 3), young (yellow 4), girls (green 5), but (blue 6), Violet (7) gives (grey 8), willingly (white 9). For the tolerance bands get (gold 5%) some (silver 10%), now (none 20%). This was long before political correctness existed and the few women in engineering had to "just live with it". There is a larger space between the gold and red bands than between any other adjacent bands. So that's 28 followed by 7 zeros, or 280,000,000. Here's a good description http://wiki.xtronics.com/index.php/Resistor_Codes and here's a website that decodes them for you. http://www.dannyg.com/examples/res2/resistor.htm Poor me, I had to use a little cardboard thing. :-) I read this as 280,000,000 ohms with 5% tolerance and 50 ppm temperature coefficient, but when I use a digital meter to read the resistance it comes in at 270,000 ohms. I noticed a small hairline crack in this resistor and when I poked it with a pin a small flake of the outer coating fell off. 280,000,000 ohms seems like an awfully large value to me. Could this be a correct reading? Either you meter is way off, you are reading it wrongly, or the resistor has really changed with age. 280m ohms is just about right. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM |
#4
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Help reading 5-band resistor?
Rich Webb wrote:
On Sun, 24 May 2009 10:41:43 -0700, Readily Visible wrote: I have a resistor in an analog VOM meter that I suspect is bad. It is exclusive to the 1x ohm scale, which is now reading as if it were the 1000x ohm scale. The color bands are as follows: Red Grey Violet Gold Red 287 / 10 (e.g. 28.7) at 2% tolerance. I figured that was probably closer to reality so I salvaged up a 100 ohm and a 39 ohm resistor and put them in parallel to get 28 ohms and the 1x ohms scale is reading close to normal. Thanks! |
#5
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Help reading 5-band resistor?
Readily Visible wrote:
Rich Webb wrote: On Sun, 24 May 2009 10:41:43 -0700, Readily Visible wrote: I have a resistor in an analog VOM meter that I suspect is bad. It is exclusive to the 1x ohm scale, which is now reading as if it were the 1000x ohm scale. The color bands are as follows: Red Grey Violet Gold Red 287 / 10 (e.g. 28.7) at 2% tolerance. I figured that was probably closer to reality so I salvaged up a 100 ohm and a 39 ohm resistor and put them in parallel to get 28 ohms and the 1x ohms scale is reading close to normal. It seems the 5 and 6 band codes are different than the 4. Here's a correct caclculator: http://samengstrom.com/nxl/2020/6_ba...e_page.en.html Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM |
#6
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Help reading 5-band resistor?
On Sun, 24 May 2009 20:04:03 +0000 (UTC), "Geoffrey S. Mendelson"
wrote: Readily Visible wrote: Rich Webb wrote: On Sun, 24 May 2009 10:41:43 -0700, Readily Visible wrote: I have a resistor in an analog VOM meter that I suspect is bad. It is exclusive to the 1x ohm scale, which is now reading as if it were the 1000x ohm scale. The color bands are as follows: Red Grey Violet Gold Red 287 / 10 (e.g. 28.7) at 2% tolerance. I figured that was probably closer to reality so I salvaged up a 100 ohm and a 39 ohm resistor and put them in parallel to get 28 ohms and the 1x ohms scale is reading close to normal. It seems the 5 and 6 band codes are different than the 4. Here's a correct caclculator: http://samengstrom.com/nxl/2020/6_ba...e_page.en.html Or this free app from Schematica. http://www.schematica.com/resistor_color_codes/Resistor.htm I'm okay with the normal bands but always screw up the gold/silver multipliers -- and the tolerance bands? Fuggedaboudit. -- Rich Webb Norfolk, VA |
#7
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Help reading 5-band resistor?
Geoffrey S. Mendelson wrote:
Readily Visible wrote: Rich Webb wrote: On Sun, 24 May 2009 10:41:43 -0700, Readily Visible wrote: I have a resistor in an analog VOM meter that I suspect is bad. It is exclusive to the 1x ohm scale, which is now reading as if it were the 1000x ohm scale. The color bands are as follows: Red Grey Violet Gold Red 287 / 10 (e.g. 28.7) at 2% tolerance. I figured that was probably closer to reality so I salvaged up a 100 ohm and a 39 ohm resistor and put them in parallel to get 28 ohms and the 1x ohms scale is reading close to normal. It seems the 5 and 6 band codes are different than the 4. Here's a correct caclculator: http://samengstrom.com/nxl/2020/6_ba...e_page.en.html Geoff. Thanks Geoff. I bookmarked it. |
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