RM HLA 150 Plus RF Transistor Replacements

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kilimax
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RM HLA 150 Plus RF Transistor Replacements

Post by kilimax » 27 Sep 2017, 15:22

Hello,

I have one of the above amplifiers that has went lame on me, only producing around 50% of the rated output. I suspect that one of the MRF 455 transistors has went the way of the Dodo but before I order replacements, I was considering replacing these with more efficient devices so that I am not driving these too hard into saturation for the same given output power.

Unfortunately, I'm limited to a transistor case size the same as the 455 so my choice might be limited. I can purchase a matched pair of SD1446 devices which are rated slightly above the 455s. MRF 454s also seem to have higher rating at around 80 watts per device but not sure of the size. I'll most likely get my devices from rfparts so I may drop them an email to ask.

So, does anyone have any recommendations on any different devices that could be used?

Thanks
Kilimax - Drew
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speeddemon
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Re: RM HLA 150 Plus RF Transistor Replacements

Post by speeddemon » 27 Sep 2017, 23:51

Hi kilimax I would Go with match pair of sd1446 or match pair of 2sc2879's :ugeek: for even more power output bro :thumbup:

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Re: RM HLA 150 Plus RF Transistor Replacements

Post by kilimax » 28 Sep 2017, 11:34

speeddemon wrote:Hi kilimax I would Go with match pair of sd1446 or match pair of 2sc2879's :ugeek: for even more power output bro :thumbup:
Yeah 2sc2879s would be my choice but they won't fit. That's my problem.

Looks as though the 1446 is the only practical alternative.

Thanks
Kilimax - Drew
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Re: RM HLA 150 Plus RF Transistor Replacements

Post by speeddemon » 28 Sep 2017, 20:33

Hi kilimax your welcome ..take care n cheers n 73's. :thumbup:

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kilimax
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Re: RM HLA 150 Plus RF Transistor Replacements

Post by kilimax » 29 Sep 2017, 21:29

In the end, I went for the matched pair of SD1446 devices from rfparts.
Kilimax - Drew
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I've changed my equipment so many times, I've forgotten what I have

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speeddemon
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Re: RM HLA 150 Plus RF Transistor Replacements

Post by speeddemon » 29 Sep 2017, 21:51

Hi kilimax. its the wise n best choice for transistors for the amp . Gd luck n cheers n 73's

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