re: Uniden ARX-1250/ARX-2125 220MHz amp update
I've sent pictures of the Uniden ARX-2125
amplifier to Roland at Amplifier Tech to
see what he can do for us.
I have a modified unit (removed the hybrid
driver and the first polyfet driver module),
which delivers over 130 watts all day long,
no problama. You should expect your unit to
do the same power level.
Uniden (Micom made) amps were sold with the
ARX-2125 and the ARX-1250 model numbers,
making the same basic amp, just a different
physical package. The ARX-2125 unit appears
to be made in/for the multi unit shelf design
and the ARX-1250 is the stand alone single
package.
It's my opinion the ARX-2125 amps should do
well over 125 watts output when biased and
driven properly. You might take out the hybrid
and pre drive module to directly drive the
output stage power divider like I do. I don't
see any need to run the amplifiers in AB linear
mode when class C should work better. I will
compare the various bias points if & when I
receive the bias board information.
I can Email pictures to anyone who cares to view
them. It's my hope that Roland has some paperwork
on the Milcom ARX-2125 bias board and control circuit.
Milcom morphed into Cresend and they were nice
enough to fax me the basic manual for the similar
current 450 MHz amp, but there is no actual
technical information in the paperwork, just
operational and led light description type info.
If you're chasing your tail for any technical
information, you can look up the Polyfet F1004
device on the Polyfet web site (it's not that
great of a data sheet). With an 80 watt rating,
these devices should easily do the 130 plus
watts from the 2125 chassis, only limited by
power supply and heat sink.
cheers,
skipp
www.radiowrench.com/sonic
> "John Everson" <[EMAIL PROTECTED]> wrote:
>
> > "Rick & Charlotte" <[EMAIL PROTECTED]> wrote:
> > I am running one of these amps right now
> > with around 100mw drive I am getting around
> > 55 watts at 224.420 stable output with no spurs
> >
> >
> Right On Rick,
> It's good to hear that you have the amp up
> and running. Nice that you were able to do
> what I was never able to get around to. 55
> watts with 100 Mw drive.... Awesome.
> 73 de John AB6LI
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