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RM-3 MOSFET TRANSISTOR

Discussion in 'Amplifiers' started by TonyV225, May 10, 2010.

  1. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    What do these RM-3 Mos transistors actually put out? I see these being used in different smaller amplifiers and was wondering how much power AM and SSB they will produce and what the drive is they will take??

    I see these little RM Italy amplifiers run these and I often wonder if their worth buying them as people do. Will they produce 50 watts even?? Or are they more like a 30 watt transistor?? That would be funny considering a dual final radio will do 30 watts.



    I was just looking around on the net and see these little KL-40 and KL-60 amplifiers and nobody really says what the heck they actually do for power. There so damn cheap I cant hardly believe they would do much for output but what do I know Ive never owned one so thats why I am asking who really knows about these transistors?? Curiosity killed the cat kind of thing. ;) :confused:
     

  2. dudmuck

    dudmuck Active Member

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    Ive seen claims that RM3 is HUF75345P3, but this is dubious since this fairchild part has gate charge/gate capacitance which is an order of magnitude worse. Not something you want for 27MHz.

    More likely its just like ERF-2030: cherry picked IRF520 for highest gain and/or efficiency.
     
  3. Highlander_821

    Highlander_821 Amour d'Ecosse

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    I have heard several techs say that they are IRF-520 mosfets.
     
  4. bob85

    bob85 Supporting Member

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    tony,
    the last rm3 amp i have had on a watt meter was the kl203, it made 122w fm from 10w drive, thats pushed very hard, 5w drive makes about 100w fm,

    id say neither hufs or 520's are rm3's,
    rm3's got too expensive to warrant repairing the little rm's so i tried both in rm3 amps even rebiased them,
    neither work right.
     
  5. earthquake

    earthquake Member

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    sorry its an old post now only just seen it!! not sure if iam on the right track here but! i thourght they were ms1307!!!!??? the same that was in some of the cte amps!!! ive replaced the rm 3s with these and all seems good!!! not sure if this is any help but thats what i have found anyway 73s.
     
  6. Dodgem250

    Dodgem250 Active Member

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    The "RM3", also known as 2N6045, is a 75 watt/100v NPN power transistor. The mystery behind the RM3 is they use what ever transistors they get their hands on in bulk pricing and cross the factory stand and restamp the transistors, in house, with the RM3 number. Not all RM3 transistors that come from RM Italy are the same, there is about 15 different variations that have been used over the years.
     
  7. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    You gotta love it when they stamp their part number on someone elses part!!
     
  8. RatsoW8

    RatsoW8 Supporting Member, W9WDX ARC Member - WD8T

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    I had an RM amp that was dead out of the box. Opened it up and there were three Chiclets painted black in there. Those sneaky europeans...:whistle:
     
    Chop and psycho like this.
  9. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    LMAO!!! Were they fruit or peppermint flavor??
     
  10. Superidgit

    Superidgit Active Member

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    This might be a little off topic, but I make rachet wrenches. I can say for a fact Snap-On, Craftsman, Kastar, Bluepoint, and a few others are all the same. Just the stamp is different.:mellow:
     
  11. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    i actually want some of those i was just looking at them!!! I worked at Broan Manufacturing in Hartford Wisconsin and they make ceiling fans bathroom fans stove range hoods with fans and I can also tell you a secret....PSSSSSST I made product with Broan,Sears Kenmore, Nautilus and a few other namebrand tags and tacked boxes for shipping with all these names ;)
     
  12. mackmobile43

    mackmobile43 Jock Supporter

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    They aren't the only manufacturer who makes the very same items for those "NAME BRAND" stores.:whistle:
     
  13. Grogan

    Grogan W9WDX Amateur Radio Club Member

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    I had often wondered about RM amps and the RM-3 transistor value. Is there any more info or any updated info on this mystery? and what do they really put out and what input wattage and swing will they handle safely on AM and SSB...........solve the mystery?
     
  14. Mudfoot

    Mudfoot Sr. Member

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    I can spot the difference between a Snap-On and an Craftsman anyday.
     
    2 people like this.
  15. 9C1Driver

    9C1Driver Sr. Member

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    Nothing really has changed. An amp like a KL203 is still very much a low drive amp good for 100-150 watts depending on how you drive it. For 68 bucks it's a cheap light duty throwaway amp when it brakes.
     

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