Fuse ratings, use smaller amp fuses or not.

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original45
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Fuse ratings, use smaller amp fuses or not.

Post by original45 » 14 Jun 2018, 06:42

Went through a few fuse holders I had on radios some from decades back not used since.
On radios they range from 1,5amp to 5amp fuses.

So do use a smaller amp fuse inline than required ,and does it offer any real extra protection or benefit as opposed to the specified fuse.

One I noted was the Lincoln mk1, I understand it should require a 10 amp fuse but actually has a 5amp fuse inline ?.

So what's your choice,do you use smaller amp fuse

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cb4ever104
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Re: Fuse ratings, use smaller amp fuses or not.

Post by cb4ever104 » 14 Jun 2018, 07:30

original45 wrote:
14 Jun 2018, 06:42
One I noted was the Lincoln mk1, I understand it should require a 10 amp fuse but actually has a 5amp fuse inline ?.
The manual says 4.5A , so I've no idea why you have a 10A there . A 5A seems fine .
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Re: Fuse ratings, use smaller amp fuses or not.

Post by original45 » 14 Jun 2018, 08:19

What threw me was before I even checked the fuse in the original cable with the radio I looked online for spare cables, those I found all stated comes with 10amp fuse.

So being a fool bought ten amp spare fuses along with the new cable.

When I finally got the cable out that came with my radio it had a 5amp fuse. So again I ordered 5amp fuses for spares.

In honestly I hold my hands up I quickly scanned the manual but didn't spot it's fuss rating in.

It then got me looking at all the radio gear I have and fuses.
One had a screw in side ,yes I kid you not.others were 5amp 3amp .

So looks like more fuses are needid.
I think the old school cb were a2amp fuse? .but have spotted some 1.5amp fuses

But because I have found them all diff rated and was interested to hear if anyone uses under rated fuses if theirs any point.

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Re: Fuse ratings, use smaller amp fuses or not.

Post by cb4ever104 » 14 Jun 2018, 08:27

I'd use a 3A in any single final stage radio , and a 5A for the rest . Some of the newer higher power mosfet radios might need a bigger fuse , but I don't have any .
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Re: Fuse ratings, use smaller amp fuses or not.

Post by Tim » 14 Jun 2018, 08:56

Fuse rating largely depends on the output power of the radio, the higher the output the more Amperage drawn the higher rating both fuse and power cable needs to be and always use fast blow fuses.

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Re: Fuse ratings, use smaller amp fuses or not.

Post by The Collector » 15 Jun 2018, 19:15

I use "fast blow" fuses on our hairdryer ;)

I'll get my coat.

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Re: Fuse ratings, use smaller amp fuses or not.

Post by original45 » 15 Jun 2018, 20:35

Lol, Thank you all . Got a better idea now and will stick with your advices.
Ta

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Re: Fuse ratings, use smaller amp fuses or not.

Post by ch25 » 15 Jun 2018, 21:08

Since my power supply acts faster than a fuse, i got rid of them long time ago.
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Re: Fuse ratings, use smaller amp fuses or not.

Post by Tim » 15 Jun 2018, 22:27

So that means your radio IS the fuse. :eh:

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Re: Fuse ratings, use smaller amp fuses or not.

Post by ch25 » 15 Jun 2018, 22:43

No, power supply does the job. Over voltage, over current, temperature, shortcut protection.
When I connect cross wired radio it just shuts down.
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Re: Fuse ratings, use smaller amp fuses or not.

Post by spyder3 » 18 Jun 2018, 15:09

My approach:
Power (W) = U * I
Means I = W/U and roughly
12w radio up to 2A fuse
35w radio up to 5A fuse
500W linear 60 A fuse

However, the fuse protects your equipment and assets from fire if shortcut happens but doesn’t save your radio from the damage.
If you want to protect your radio use electronic current stabilizer or electronic fuse. Some power supply units have it as ch25 mentioned.
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