Have you hit the wall looking for 2879's? Here is a possible replacement

[freecell]

seriously though, if you're looking for rf power transistors that can provide 100W apiece then don't pass up the 50 mhz. devices, the gain of which increase by 3 dB. when operated @ 27 mhz.. this includes the MRF492, SD1446 and the SRF3800. be warned though because with the increased gain the devices become more (drive) input sensitive

 

[357]

The "C" version is RoHS compliant. When you have a choice, you want to avoid compliance here since it eliminates the Beo ceramic which has better thermal conductance.

The 950 is more difficult to mod than other HF rigs because just about every part of the audio circuitry, gets replaced with a custom modulator PC board.

RD100HHF1-101
RD100HHF1-102
RD100HHF1-103
RD100HHF1
RD100HHF1C
RD100HHF1C-501

are these all the same?
I can source RD100HHF1-103


orange is the RD100HHF1-101 black is RD100HHF1C-501
What am I seeing here?

 

[VA7JHI]

The 28 volts might be a problem for mobile use…

Try this. <—LINK

That will give you 24VDC at 12A from 12VDC… at least, according to the specs.

 

[Captain Kilowatt]

Try this. <—LINK

That will give you 24VDC at 12A from 12VDC… at least, according to the specs.

Oh I am well aware of such devices but they are generally just a bandaid with most of the sticky stuff gone. IOW they do not work that great, especially at high power demands. I have tried them at low power with acceptable results but high power applications and they start to fail.

 

[VA7JHI]

Oh I am well aware of such devices but they are generally just a bandaid with most of the sticky stuff gone.

Well, the first one I bought would put out 20 amps at 40 volts into a 2Ω load (800 watts) on a giant heat sink, pretty much indefinitely.

Then, I ordered four more.

Whenever I hear someone say "such devices" I know it means they don't have any experience with the specific device I was talking about.

 

[linearone]

Well, the first one I bought would put out 20 amps at 40 volts into a 2Ω load (800 watts) on a giant heat sink, pretty much indefinitely.

Then, I ordered four more.

Whenever I hear someone say "such devices" I know it means they don't have any experience with the specific device I was talking about.

That exact same device is sold in a few places online. Actually that's wrong. It's sold in a ton of places. I bought a few of them to experiment with. 1200 w is a bold lie no matter what the heatsink is. The point is you just can't get that much heat off the die of those transistors. I'll be very honest. I didn't think of even seeing where they would reliably run at. I was just trying to dial them up to 1200 w and they would blow.

 

[Captain Kilowatt]

Well, the first one I bought would put out 20 amps at 40 volts into a 2Ω load (800 watts) on a giant heat sink, pretty much indefinitely.

Then, I ordered four more.

Whenever I hear someone say "such devices" I know it means they don't have any experience with the specific device I was talking about.

The term "such devices" simply means those devices that do as you pictured. There are a lot of different ones out there, and ANY of the cheaper types OF THOSE DEVICES will NOT meet what they claim for results. They are fine for low current applications but performance drops off quickly with high current demands.