hello all,
>From the old box.
It takes me 28 years back, when we needed to produce about 60w composite for
TV supervision on the high way. freq was in the 460 Mc/s band.
Tried with QQE06/40 something ( like a 829B ) but we had no stable results.
So we thought about this 90? combiners and transister power amplifiers. Our
power transistors devellopment dept. ( Philips Eindhoven ) Mr Zwanen just
finished the first prototypes of the BLYxx serie . He builded the Amps in
the research lab. 7 Amps of different power were used with 6 combiners and
10 dummy loads with adapted power ratings. We had good stable results for
over 7 years, when in the early eighties the whole system was replaced.
Sure the dummy loads had'nt that much power to dissipate over the years.
The whole system cost was about three years of sallary i earned at that
time. And we even did'nt get the CD " If I was a rich man " with it .......
Jos on4kj
----- Original Message -----
From: "Phil Clements" <philk5pc@tyler.net>
To: "Brian Moran" <brianmo@yahoo.com>; <amps@contesting.com>
Sent: Friday, July 11, 2003 5:16 PM
Subject: Re: [Amps] Revisited: Power Combiners, cheap amps.
> Sent: Thursday, July 10, 2003 3:09 PM
> Subject: [Amps] Revisited: Power Combiners, cheap amps.
>
>
> > I perused the ~19 meg archive for "power combiners" --
> > from my read, the suggestions were mixed for trying to
> > sum the outputs of two HF amps. Has anyone tried the
> > following?:
> >
> > Take two relatively-inexpensive amplifiers, say,
> > heathkit sb-220's. Make sure that they both work
> > reasonably well. With the hybrid combiner available
> > from CCI (make sure to use those resistors in case of
> > failure of one amp!), combine their outputs.
> >
> > Again, WITHOUT having done this, it seems to me that:
> >
> > With SB-220's at about $0.57 a watt (700 watts) or so
> > OUT (CW), $~400 recent prices used (conservatively))
> > they are seemingly inexpensive...
> >
> > Tuning would have to be done individually, then the
> > amps switched into the network.
> >
> > Has anyone tried this?
> > Brian, N9ADG
>
> An easier and cheaper method is to put up another antenna and feed each
one
> with a seperate amp. OH2BH does this at his contest station. Another beam
is
> cheaper than a combiner unless you have a closet full of big carborundum
> resistors.
>
> (((73)))
> Phil, K5PC
>
>
>
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