4th Oct 2022, 3:38 pm | #1 |
Hexode
Join Date: Jan 2018
Location: Cannock, Staffordshire, UK.
Posts: 268
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DAC90 help
Ok, so I acquired a DAC90 and am in the process of restoring it.
However, while I was just checking a few resistors i noticed a discrepancy on the trader sheet, R19 "Surge limiter" is 150ohm. But the one in this set reads as 8.2ohm. It's one of the dog bone type - do they ever go out that far? especially "down to" ? Also does anyone know the best way to clean smokers nicotine brown, this one is really bad. Everything on the chassis is brown. Thanks Derek |
4th Oct 2022, 5:28 pm | #2 |
Octode
Join Date: Dec 2010
Location: St Ives, Cambridgeshire, UK.
Posts: 1,180
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Re: DAC90 help
Screwfix's degreaser is good stuff, wear rubber gloves though. I've used it on several valve radio chassis with excellent results. Wash it off thoroughly afterwards.
https://www.screwfix.com/p/no-nonsen...ser-5ltr/88668 I've seen old 'dog bone' resistors go low yes, some high, some still within tolerance. I think the original is 1W from memory. Andrew
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4th Oct 2022, 5:59 pm | #3 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,550
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Re: DAC90 help
Firstly what does the colour code read (assuming it's still readable)? Secondly, when in doubt, disconnect one end of the resistor and measure it again. Unless obvious from the circuit, it might be in parallel with other components. The resistor might be connected across the scale lamp(s) in which case the total will be the resistance of the lamps in parallel with the resistor.
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4th Oct 2022, 7:13 pm | #4 |
Hexode
Join Date: Jan 2018
Location: Cannock, Staffordshire, UK.
Posts: 268
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Re: DAC90 help
I'm not sure it's the original resistor. Someone has worked on the radio befor, for example the smoothing cap is an RS-Componets one.
The resistor has no markings, i assumed they had "burnt" of with age, but not so sure. It has been checked out of circuit and it reads 8.2ohm I've ordered a 5w 150ohm one. |