Fuse resistor substitute 68ohms 60mA

[Hifibythekg]

There is a a 68 ohms 60mA fuse resistor found in the Yamaha A-1 and other Yamaha amps of the same period.

Could anyone tell me what is the best substitute?

 

[avionic]

68Ω 1/4 watt flame proof

 

[Martin.Ca]

https://www.audiokarma.org/forums/index.php?threads/fusible-resistor-in-a-1.703867/

 

[Hifibythekg]

Thanks Martin, that’s a good reference. Avionic provides a specific link to Mouser but they now list that component as obsolete.
In the UK, Farnell offer 8 that are similar does anyone know which of these is an appropriate substitute?
https://uk.farnell.com/w/c/passive-...-leaded&power-rating=250mw&range=inc-in-stock

 

[Martin.Ca]

68ohm 60ma fusible flameproof resistors are no longer available, and I think Avionic says a fusistor is a bit of overkill where it is, they apparently wander over time anyways. Just replace with Avionic's suggestion, the 68Ω 1/4 watt flame proof resistor.

would one that's got "Flame retardant epoxy conformal coating (red brown
color)" suffice maybe?

https://www.mouser.ca/ProductDetail/Vishay-Dale/CCF0768R0GKE36?qs=QKEOZdL6EQrIkUKwpnqdug==

 

[Hifibythekg]

Thanks Martin. The Mouser one you suggest looks likely to be a good replacement but in the UK I’d incur big shipping charges for an item of a few cents. In my Farnell list, can you tell me which of these 8 similar resistors looks to be the best replacement?
https://uk.farnell.com/w/c/passive-...-leaded&power-rating=250mw&range=inc-in-stock

 

[petehall347]

try at RS you will need an account for free shipping

 

[Hifibythekg]

Thanks Pete, yes, good tip, RS are a very good option over here.
However, for these components they have high minimum orders.. and I don't think they have the right one as quite a lot are on long backorder.
Are you able to judge whether one of those eight from Farnell might be appropriate?

 

[petehall347]

i use metal film .
it would be lots cheaper getting from a trusted ebay seller unless of course you are buying enough parts to make it worthwhile

 

[Hifibythekg]

Yes, I think that's correct but the originals had a flame retardant quality as well.
How necessary is this? It's hard to find all these specs in one resitor. Is there another spec to look out for that will cover this flame retardant / flameproof spec?

 

[petehall347]

metal film don't set on fire .. well i have never seen one do that .

 

[Hifibythekg]

So fair to say that any metal film, 68 ohm 250mW resistor from a known brand / supplier should be fine to replace the originals?

 

[petehall347]

yes so long as they are flameproof ones . i just looked it up and apparently not all are .

 

[Hifibythekg]

Exactly.. did you see a metal film, 68 ohm 250mW resistor that was flameproof?

 

[petehall347]

the ones i have have not set on fire when overloaded .
reading this suggest metal oxide would be a better choice . https://passive-components.eu/resistors-non-wirewound-resistors-metal-film-foil-and-metal-oxide/

 

[Hifibythekg]

Just found this at Farnell
https://uk.farnell.com/neohm-te-con...ial-metal-oxide/dp/3229769?st=flame resistor#

 

[Hifibythekg]

Now this is a 500mW rather than a 250mW. The spec sheet says that the firm offers them but I can't see them supplied by anyone in the quarter watt spec.

 

[Hifibythekg]

In this position on the board will a 500mW one be ok?
Original spec was 68ohms 60mA.

 

[Hifibythekg]

RS do the same / similar one, again in 500mW.
https://uk.rs-online.com/web/p/through-hole-fixed-resistors/1870755/

Very hard to source these in a 250mW spec

 

[petehall347]

do not go higher wattage as its same as putting a higher amp fuse in a circuit .