EMRFD Message Archive 5645

Message	Date	From	Subject
5645	2011-01-03 02:02:24	brainerdd	QRO FET
Freescale has announced a new device that looks real good for QRO operation. The MRFE6VP61K25 is 2 LDMOS FETS on a single die. It is rated for 1.8 to 600 MHz operation. It is rated for 1250 watts of CW output into an SWR as high as 65 to 1. It is rated for 50V operation. At 230 MHz, it has a gain of 24 dB at 1250 watts output with 50 V on the drain. Likely even higher gain at HF. That means less than 6 watts in = 1250 watts out! Digikey lists them as in stock and $270.90 each. Dave - WB6DHW <http://wb6dhw.com
5646	2011-01-03 04:41:07	w4zcb	Re: QRO FET
You might wish to take a look at the link. http://lists.contesting.com/_amps/2005-04/msg00451.html W4ZCB ----- Original Message -----
5647	2011-01-03 04:56:11	Robert Bennett	Re: QRO FET
That means less than 6 watts in = 1250 watts out! Hmm.......I guess getting 1250Watts of RF out is going to be lot easier than shifting 1KW+ heat!! 73 Robert
5651	2011-01-03 10:08:25	Jim Miller	Re: QRO FET
I wonder what Freescale recommends as heat sink arrangement. I would think they would have something if for no other reason to demonstrate performance in their datasheet. jim ab3cv [Non-text portions of this message have been removed]
5652	2011-01-03 16:07:19	kb1gmx	Re: QRO FET
The usual deal is a .25 inch (or thicker) copper plate backed up by a big heat sink possibly fan cooled to keep it smaller. The slab of copper is to spread the heat from the small area of the transistors and couple it to the aluminum heat sink. I'm doing a BLF278 (gemini VHF FET) 2M amp expected to do 350W out and about 600W in so thats the soluti
5653	2011-01-03 17:15:47	R Wall	Re: QRO FET
A good place to purchase electrical copper bus bar is a metal scrap dealer. Or a electrician or Switch Board manufacturer. Roderick Wall, vk3yc.