Resistor colour code - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

AC/HL · 18th Jul 2018, 9:10 pm

Assuming they're faulty of course. They don't look damaged, although the ones with the brass caps can be deceptive.

Oldcodger · 18th Jul 2018, 9:37 pm

Last time I heard of the old Tip/spot idea was doing my R&LT "A" , way back in the late 60's. But being three banded resistors, I'd say they are 2.2 ohms , and 20% tolerance as in those days the default no tolerance band was 20%.
My best suggestion to the OP is to measure them out of circuit, but I'd suggest from past experience that the cap one will not like this. So why not as suggested get a pair of 2.2 ohm, half a watt to be on safe side. But from memory, to add confusion, if these are in the output of a class B stage, then there'll be an optimum value of quiescent current in the output pair that needs adjusted after a resistor change.
For the OP ,I remember the mnemonic I learned at college all those years ago for three banders, but I think I'd get at least a yellow card for posting it , so here's a link
https://en.wikipedia.org/wiki/List_o...code_mnemonics.

Freya · 19th Jul 2018, 9:03 am

Some digging reveals the OP also asked about a circuit for a Bush SRP52, being the same for the fidelity.
here are some previous posts containing the circuits
layout https://www.vintage-radio.net/forum/...6&d=1439636303
Schematic https://www.vintage-radio.net/forum/...8&d=1439648467

2.2k Resitors in question are R13 and R14, I would say R14 has obviously been previously replaced.

John10b · 19th Jul 2018, 10:35 am

Stephen I think you mean 2.2ohm ?
Cheers
John

18th Jul 2018, 9:10 pm	#21
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Resistor colour code Assuming they're faulty of course. They don't look damaged, although the ones with the brass caps can be deceptive.

18th Jul 2018, 9:37 pm	#22
Oldcodger Nonode Join Date: Oct 2014 Location: West Midlands, UK. Posts: 2,181	Re: Resistor colour code Last time I heard of the old Tip/spot idea was doing my R&LT "A" , way back in the late 60's. But being three banded resistors, I'd say they are 2.2 ohms , and 20% tolerance as in those days the default no tolerance band was 20%. My best suggestion to the OP is to measure them out of circuit, but I'd suggest from past experience that the cap one will not like this. So why not as suggested get a pair of 2.2 ohm, half a watt to be on safe side. But from memory, to add confusion, if these are in the output of a class B stage, then there'll be an optimum value of quiescent current in the output pair that needs adjusted after a resistor change. For the OP ,I remember the mnemonic I learned at college all those years ago for three banders, but I think I'd get at least a yellow card for posting it , so here's a link https://en.wikipedia.org/wiki/List_o...code_mnemonics.

19th Jul 2018, 9:03 am	#23
Freya Octode Join Date: Jan 2009 Location: Falmouth, Cornwall, UK. Posts: 1,990	Re: Resistor colour code Some digging reveals the OP also asked about a circuit for a Bush SRP52, being the same for the fidelity. here are some previous posts containing the circuits layout https://www.vintage-radio.net/forum/...6&d=1439636303 Schematic https://www.vintage-radio.net/forum/...8&d=1439648467 2.2k Resitors in question are R13 and R14, I would say R14 has obviously been previously replaced. __________________ Stephen _________"It`s only an old telly" ___

19th Jul 2018, 10:35 am	#24
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Resistor colour code Stephen I think you mean 2.2ohm ? Cheers John