Irf520 mosfet question

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Damselfly
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Irf520 mosfet question

Postby Damselfly » Saturday 24th Jan 2009, 11:03

Hi. My rig used 2 x irf520 mosfets for its final stage. What would be a safe operating power for both of these on fm and ssb without frying them please? Would they have longevity coping with 10w carrier on fm and approx 25 watt pep on the ssb? It's a new radio and i don't really want to be replacing components regularly. Regards. Damian.

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Animal
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Irf520 mosfet question

Postby Animal » Sunday 25th Jan 2009, 5:38

Set it to factory settings.
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Damselfly
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Re: Irf520 mosfet question

Postby Damselfly » Sunday 25th Jan 2009, 7:02

Animal wrote:Set it to factory settings.
Everything is still set to factory settings apart from the alc. I needed to turn up the alc slightly as the ssb power was going no higher than about 2-3 watts even when shouting down the mic which isn't really acceptable. Now, back on topic? Anyone know if these mosfets will happily survive under these parameters please? Regards.

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Animal
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Irf520 mosfet question

Postby Animal » Sunday 25th Jan 2009, 21:40

Factory recommendations are there for a reason.

If you exceed these parameters then don't expect your finals to last as long as they would in normal service. You're also likely increase the risk of IMD, degrade the signal to noise ratio, etc, etc

I haven't looked up the factory recommendations but you should.
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violator
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Re: Irf520 mosfet question

Postby violator » Wednesday 10th Jun 2009, 5:18

The irf520 is a 20 watt transistor. Hope this helps.


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