[NLRS] [Mw] 1296 Amplifier Transistors

[Zack Widup]

I have yet to put together the kit with the MRF9045 LDMOS device I got from
WA5VJB at the CSVHF conference. It looks promising. a couple watts in for 45
watts out on 1296. Kent said I could probably get more like 50 out if I used
higher quality cermaic chip caps on the input and output.

73, Zack W9SZ

On Fri, Sep 11, 2009 at 12:13 PM, Bill Ress <bill at hsmicrowave.com> wrote:

> Hi Darrell,
>
> The web site shows the device as "refurbished." Now I'm not sure what
> that means relative to a semiconductor device. These could well be
> devices that fell out of the Motorola manufacturing specification
> limits. Aaah, but the price is right.
>
> Regards...Bill - N6GHz
>
> Darrell wrote:
> > Hi Scott and Group;
> > I would caution against purchasing those MRF286 devices from China. I
> > purchased a number from them Directly through PayPal on their Web.
> > Problem:
> > Motorola specks input Capacitance as 140pF, theirs is close to 165 to
> > 170pF Input and their output Capacitance is approaching 100 relative
> > to 51pF as in TRUE Motorola Specks.
> >
> > So unless you can model the PCB and change Device Pinch Off Voltage
> > as well as Ciss & Coss in the modeling software there are problems in
> > replacing the TRUE MRF286  device.
> >
> > Regards & Thanks, Darrell
> >
> > At 08:51 AM 9/11/2009, Scott wrote:
> >> Here's a source of the MRF286 transistors as used in the W6PQL 1296
> >> amplifiers.  These are the flange mounted devices so they should be
> >> easier to build with as you don't have to try to solder them to a heat
> >> spreader.  I have no affiliation with this guy (Hong Kong), but it sure
> >> seems like a decent deal....
> >>
> >>
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360183767487&ssPageName=ADME:B:WNASIF:US:1123
> >>
> >> --
> >> Scott N0EDV
> >> http://corbenflyer.tripod.com/
> >> Flying Corben Junior Ace - Building RV-4
> >> Gotta Fly or Gonna Die
> >>
> >>
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