The infamous "RM3 MOSFET", best deal in CB history

[garikfox]

I was wondering If anyone knowing transistors may help out a bit here.

Iv'e been reading on the web that the RM3 MOSFET used in the Italian KL-203ver.6.0:(4xRM3's) is a more less a secret MOSFET, But I also hear that it's just a common MOSFET renamed by RM Italy themselves.

So I actually found out that the "Transistor" used is a Fairchild HUF75343P3

Here's the spec sheet(s):

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So I'f what I'm reading correctly this amp would be the best buy to get in CB history ! Also since the RM3's can reach a MAX of 175c thats 347f, Wow !

[garikfox]

"P.S- I thought U put a "?" in the main topic subject at the end, sorry.

[garikfox]

wow, I must be dumb, lol.

heres for above. = [/i] , LOL

[Black Lightning]

What makes you think it's the best buy to get in CB history?

[garikfox]

Price of Performance per watt ? I think that's what I mean.

[garikfox]

Off topic: How do I get a Text Sig going like u all ?

[Bow]

Iv'e been reading on the web that the RM3 MOSFET used in the Italian KL-203ver.6.0:(4xRM3's) is a more less a secret MOSFET, But I also hear that it's just a common MOSFET renamed by RM Italy themselves.

So I actually found out that the "Transistor" used is a Fairchild HUF75343P3

Where did you get this information?

[garikfox]

Iv'e been reading on the web that the RM3 MOSFET used in the Italian KL-203ver.6.0:(4xRM3's) is a more less a secret MOSFET, But I also hear that it's just a common MOSFET renamed by RM Italy themselves.

So I actually found out that the "Transistor" used is a Fairchild HUF75343P3

Where did you get this information?

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[garikfox]

Ooops wow, that lonk sucks Ill try again.


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[garikfox]

Sorry all, I guess this site doesnt like that site, lol

here is what the poster "Rick" said:

"The right MOSFET to replace the RM3 is HUF75343P3.
Amps using the RM3 have been around in the UK and Europe for over ten years now.
The IRF520 will work but with lower power output and how it will last is any ones guess.

You can find the datasheet at this URL
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If you wish to do the right job you the right device.

There are to many people guessing about MOSFET’s, one think I keep coming across is that the ERF2030 is the same as the IRF520, but they are not, if you put them on a transistor curve tracer you will see that they are not the same device and do not match."

[grimace]

can you use HUF75343P3 insted of IRF520 in the MOSFET mod and get more watts

[littlesilver3]

I read somewhere that this HUF75343P3 is also a direct replacement for the erf2030. Many people say the irf520 is but accordinf to what i read its not.

[KW KID]

How many watts are each of these good for?

[mav391]

I tried these in place of the erf2030 mod... Did not work.

I tried it in one of the rm stinger boards... did not work.

I got 8 of them from Fairchild direct and they did not work...

[elmer fudd]

Man you guys are technical! Lmao!!!

[Crusher]

You have to pay special attention to the capaitance of these mosfets.

[Wing Ding]

How many watts are each of these good for?

That's what I'd like o know, too.

[sparky17]

About 50W PEP. I've done 60W with volting.. I think they're rated at 60W also..

I replaced RM3's with IRF520's. It works, and swings the same, but the SWRs are higher (2.5:1 where it was 1.1:1 before). (Input capacitance difference?). It's worked for a couple weeks now and if it blows out, I'm out another $5, oh darn.

[Bigbadwolfb4u]

[*]I have a RM- KL-503 amp that supposedly uses the same 520 MOSFETs,I over drove this amp and fried either one or more of the MOSFETs.
I replaced the first MOSFET in the board which gave me different readings than the rest (8 total),but no luck,the amp still didn't work.
I didn't realize how little wattage you have to drive these amps with ( my mistake).
I have looked everywhere for RM schematics for this amp that shows the correct values of these MOSFETs with no luck.
My question now is,does anyone out there fix these amps?
Only spent a little over 200 bucks for it brand new but would like to repair it.
The 503 HD( high drive) will take more input wattage,which I wish now that I had bought,
Stuck with what I have.
Help!???

[Bombero]

[Bigbadwolfb4u]

Thanks for the update on the schematic,however it still doesn't say what type of MOSFETs these are( #,or values)
I guess this is their big secret.

[Bombero]

KL503 has 9 irf520 type mosfet transistors in a 1 driving 8 configuration. You are limited by the single driver as to what you can put into it.