http://elecraft.85.s1.nabble.com/News-from-Visalia-tp4914396p4919366.html
It's not shown on the datasheet. However, the VRF2933 is
ARRL standard). Since the VFR2933 is a higher gain part
the IMD performance might be a bit worse at maximum output.
at 50V - the KPA-500 is not pushing them at 500W. I'd look
for IMD numbers on the mid to high 30's (ARRL spec).
... Joe, W4TV
> -----Original Message-----
> From:
[hidden email]
> [mailto:
[hidden email]] On Behalf Of juergen
> Sent: Saturday, April 17, 2010 7:50 PM
> To:
[hidden email]
> Subject: Re: [Elecraft] KPA500 active devices!!
>
>
>
> Hi Joe
>
> Have you seen any IMD data on these devices?
>
>
> John
>
>
> --- On Sat, 4/17/10, Joe Subich, W4TV <
[hidden email]> wrote:
>
> > From: Joe Subich, W4TV <
[hidden email]>
> > Subject: Re: [Elecraft] KPA500 active devices!!
> > To: "'Doug Faunt N6TQS +1-510-655-8604'" <
[hidden email]>,
> >
[hidden email]
> > Date: Saturday, April 17, 2010, 4:45 PM
> >
> > The VRF2933 is rated for 300 Watts each according to the data
> > sheet on the manufacturer's web site (Microsemi) ... That
> > makes
> > their use in a 500 W amplifier reasonable from an IMD
> > perspective.
> >
> > The VRF 2933 minimum gain is also 20dB (23 dB typical) so it
> > would appear that the KPA-500 should be capable of clean
> > operation with 5 W of drive (e.g., K3 in low power mode).
> >
> > 73,
> >
> > ... Joe, W4TV
> >
> >
> >
> >
> > > -----Original Message-----
> > > From:
[hidden email]
> >
> > > [mailto:
[hidden email]]
> > On Behalf Of Doug
> > > Faunt N6TQS +1-510-655-8604
> > > Sent: Saturday, April 17, 2010 6:45 PM
> > > To:
[hidden email]
> > > Subject: [Elecraft] KPA500 active devices!!
> > >
> > >
> > > There are two VRF2933's in push-pull, so they're not
> > 750
> > > watts each, but per pair. There are only three
> > amps in
> > > existance, and no devices have been destroyed
> > (yet). Again,
> > > 500 watts is a very conservative rating. It's been
> > key-down
> > > for 10 minutes withy no problems.
> > >
> > > 73, doug
> >
> >
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