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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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15th Jul 2017, 3:12 pm | #1 |
Nonode
Join Date: Jul 2010
Location: Folkestone, Kent, UK.
Posts: 2,172
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Resistor confusion
what does the team think the value of this is please? There's 2 on the board, this one reads 270k, t'other open
many thanks |
15th Jul 2017, 3:15 pm | #2 |
Nonode
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,571
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Re: Resistor confusion
Brown, black, black, yellow with a brown tolerance band . I'd say it was 1M 1%. Did you measure the 270k with it in circuit?
Keith |
15th Jul 2017, 3:18 pm | #3 |
Heptode
Join Date: Aug 2009
Location: Liverpool, Merseyside, UK.
Posts: 704
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Re: Resistor confusion
Yep, I'd read that as 1M 1%
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15th Jul 2017, 3:20 pm | #4 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Resistor confusion
Ditto.
Lawrence. |
15th Jul 2017, 3:28 pm | #5 |
Nonode
Join Date: Jul 2010
Location: Folkestone, Kent, UK.
Posts: 2,172
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Re: Resistor confusion
thanks guys. Keith, yes 270k in circuit
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15th Jul 2017, 3:54 pm | #6 |
Nonode
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,571
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Re: Resistor confusion
Looks like there's a parallel circuit causing the lower resistance. Try lifting one end and re-measuring.
Keith |
15th Jul 2017, 4:38 pm | #7 |
Nonode
Join Date: Jul 2010
Location: Folkestone, Kent, UK.
Posts: 2,172
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Re: Resistor confusion
Thanks Keith. I admit that value had me foxed, I still read resistors in 'old money' !
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15th Jul 2017, 5:24 pm | #8 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: Resistor confusion
This is a handy site for us old'uns. Just select the number of bands. The tolerance band is the wider spaced one. Several other conversions as well.
https://www.digikey.co.uk/en/resourc...or-code-4-band |
15th Jul 2017, 5:41 pm | #9 |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
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Re: Resistor confusion
Resistors (through hole ones) are now so small and have so many bands I have to use a magnifying glass to read them.
And even then there can be ambiguity. Brown black black brown brown can be 1k (brown black black brown) 1% read one way, and 110 ohms (brown brown black black) 1% read the other. Although the brown 1% tolerance band ought to be wider than the value colours, it is often not clear. So after using a magnifying glass I then use a DVM to measure the darned thing to eliminate possibility of error. And don't get me started on the cryptic labeling of surface mount parts.... Craig |
15th Jul 2017, 6:26 pm | #10 |
Heptode
Join Date: Dec 2014
Location: Lincoln, Lincolnshire, UK.
Posts: 583
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Re: Resistor confusion
Recently bought some of these - 1MOhm. The way I see modern ones is an extra number band with standard multiplier so 100 with 4 zeros - 1MOhm.
My 10MOhm are brown, brown and black with green multiplier - 100 and 00000. My 10 kOhm are brown, black and black with red muliplier - 100 and 00 That way it just seems like the old method with an extra band. I do agree that the banding is not easy to read though |
15th Jul 2017, 7:40 pm | #11 |
Hexode
Join Date: Jan 2007
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 453
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Re: Resistor confusion
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15th Jul 2017, 8:05 pm | #12 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,562
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Re: Resistor confusion
Hi.
For most of used to the old 4-band system it certainly can cause confusion trying to interpret the 5-band and 6-band codes. With the old 4-band system it was so easy to recognise values quickly. We got used to the third band multiplier, black (tens of Ohms), brown (hundreds of Ohms), red (thousands of Ohms), orange (tens of thousands of Ohms) etc. It definitely takes longer to decide the correct value with the 5 and 6-band codes. Regards Symon. |
16th Jul 2017, 7:03 pm | #13 |
Heptode
Join Date: Dec 2014
Location: Lincoln, Lincolnshire, UK.
Posts: 583
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Re: Resistor confusion
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17th Jul 2017, 1:02 pm | #14 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,527
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Re: Resistor confusion
It gets even more interesting with proper E96 1% or E48 2% resistors when the second two bands are totally "unexpected" colours. 29.8 ohms would be red white grey gold brown for instance, though at least that would be a nonsense read backwards, unlike say 120R vs 10k.
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