1250W CW from a single power FET!!

[eagle1911]

New from Freescale, the MRFE6VP61K25H LDMOS RF power MOSFET is capable of 1250W CW power output @ 50VDC from 1.8-600MHz. My how far things have come..

MRFE6VP61K25H Product Summary Page

I had heard a price of ~250 per unit.. not too shabby for better than a kW.

EDIT: the device is actually a push-pull pair of FETs in one package.. still pretty amazing power output though.

 

[dudmuck]

That is great news!
This device can handle very bad SWR, so it should be difficult to kill.

Also take a look at the ARF15xx parts from microsemi, where you can get 750 watts per pill on HF.

In all cases, such high power devices need a copper heat spreader on the heatsink. Such heat in small space requires extra measures to dissipate adequately. Hopefully the added efficiency is worth the burden of dissipation.

 

[BOOTY MONSTER]

so that means it'll do 5000 watts in a class C crap box ?

 

[GnG8d]

so that means it'll do 5000 watts in a class C crap box ?

5000 is a conservative figure

 

[BOOTY MONSTER]

on a serious note .....
since that thing will do 1250 watts and its spec'ed to be a 22.9 db gain device does that mean it can reach that power level with just a hair over 6 watts ?

1250 - 10db is 125
125 - 10db is 12.5
round 2.9 to 3 .... a little over 6 watts

or am i misunderstanding something ?

 

[eagle1911]

That looks about right to me..

Those numbers work when I plug them in here: http://www.sengpielaudio.com/calculator-amplification.htm

 

[BOOTY MONSTER]

damn , so a old school 8719pll cb radio could fully drive a pair of them to 2500 watts !!!
pretty fricken cool

so how many hundreds of dollars do they cost .

 

[RatsoW8]

damn , so a old school 8719pll cb radio could fully drive a pair of them to 2500 watts !!!
pretty fricken cool

so how many hundreds of dollars do they cost .

Yes..and a **'er somewhere is going to buy one to feed their mag mount antenna or mobile beam. yay.

 

[eagle1911]

damn , so a old school 8719pll cb radio could fully drive a pair of them to 2500 watts !!!
pretty fricken cool

so how many hundreds of dollars do they cost .

While it certainly did not come from the manufacturer, I have heard that they run around $250 each..

 

[BOOTY MONSTER]

that doesn't seem bad when you consider it would take 12 2879s for the same power level ... and the associated transformers and other parts and pieces .
will this thing need transformers the size of paper towel rolls ??

 

[eagle1911]

Not sure on that.. possibly on the output, but possibly not. I'd have to see some sort of engineering bulletin on them or something similar to get an idea. I just ordered the Ferromagnetic-Core Design and Application Handbook by Doug DeMaw.. Once I'm done reading it I'll hopefully be able to answer questions like that without referring to other people's work.

 

[eagle1911]

so how many hundreds of dollars do they cost .

MRFE6VP61K25HR5 Freescale Semiconductor RF MOSFET Small Signal

Still very new.. 0 on hand, 50 on order. Lead time 15 weeks.

 

[Se7en]

MRFE6VP61K25HR5 Freescale Semiconductor RF MOSFET Small Signal

Still very new.. 0 on hand, 50 on order. Lead time 15 weeks.

sexy mosfet:

 

[Shockwave]

The family of these dual N-channel devices sure has changed in the last 5 or so years. The use to be twice as expensive, half the power dissipation and about 5 times more fragile to any mistakes in design or loading. I predict it won't be long now before we see hi end HF rigs on the market capable of near legal limit output. Today's switching supplies make the foundation possible in a much smaller package that could even be outboard and lightweight. The load mismatch ratings mean it's not required to have an internal antenna tuner.

The FPA should easily handle any foreseeable extreme mismatch for the brief time it would the VSWR foldback to clamp the power output at a safe level through the ALC line. As has already been pointed out the biggest problem is cooling these small devices that will develop massive heat in linear applications. The technology exists to accomplish this in a reasonably sized heatsink. Using the copper spreader, specialized thermal compounds and forced air cooling, it's on the way.

 

[Robb]

Yeah; but what about the cost vs efficiency to build one of these current-gulping beasties?

$500 in materials to build a DIY 1250 watt amp.
Thoughts/estimates?