From: Gerhard Hickl <gerhard.hickl@aon.at>
To: rsgb_lf_group@blacksheep.org
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Date: Tue, 07 Dec 2010 17:05:04 +0100
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Subject: Re: LF: Searching for Power Supply 24V/10A
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Mal, Rik!

I'm aware, that usual ATX power supplies only deliver high current on
the +12V supply, whereas the -12V  supply is rated relatively low.

And yes Mal, you're right: The +5V output usually delivers the highest
current.

The hint I gave, is only valid if you've got TWO power supplies,
delivering a sufficient current (>10A) at the positive 12V-Voltage. Then
you can connect them in series.

Mal: I'm with you.....I also prefer power supplies with a lot of
iron/copper instead of switch-mode technology because usually
"old-fashioned" power supplies radiate much less QRM especially at MF to
VLF....but sometimes it's a matter of costs. Copper is expensive
nowadays.

73
OE3GHB
Gerhard


Am Dienstag, den 07.12.2010, 14:01 +0000 schrieb mal hamilton:
> Gerhard
> It depends how much I(current you need) some only give about 1amp at 12v
> whereas at 5v you get several amps.
> also
> you do not need a regulated psu for the PA just a good transformer capab=
le
> of delivering the amps you need and plenty of C for smoothing.
> I do not use regulated psu's on any of my class D or E amplifiers, but=
 I
> have plenty of C
> mal/g3kev
>=20
> ----- Original Message -----
> From: "Gerhard Hickl" <gerhard.hickl@aon.at>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Tuesday, December 07, 2010 1:36 PM
> Subject: Re: LF: Searching for Power Supply 24V/10A
>=20
>=20
> > Hello Horst!
> >
> > The cheapest way is to obtain 2 computer-power supplies from the
> > junk-yard (=3D for free). Then you have to open both, disconnect the
> > negative supply from earth-potential (but of course NOT disconnecting
> > the earth from chassis!!!) and connect the 12V supplies in series.
> >
> > This is simple and cheap!
> >
> > 73
> > OE3GHB
> > Gerhard
> >
> > Am Dienstag, den 07.12.2010, 12:44 +0100 schrieb pa3abk:
> > > I'm using a Conrad PSU 24VDC @ 10.5A EA-PS 524-11-T from EA - German
> > > technology made in China ;-)
> > > Best.-Nr.: 510120 - 62   [Teilenummer: 35 320 133]
> > >
> > > Didn't find any spurious yet of MF and HF although  using open feede=
rs.
> > > There is also a sensor available to eliminate the voltage drop over=
 the
> > > cables.
> > > It comes with mounting brackets.
> > > A 48VDC version is available.
> > > Just check Conrad.de for details.
> > >
> > > It's also possible to use the cheaper "mousetrap" PSU's, but as QRM=
 and
> > > noise is not acceptable I choose for this one.
> > > The few euro's more doesn't justify the irritation and trouble to
> > > eliminate the QRM.
> > >
> > > Initally I had the TX with unstabilized PSU, because Class E final=
 is
> > > calculated with a certain voltage and associated L/C result was rath=
er
> > > irratic.
> > > This PSU gave me a stable PA  24VDC/5,6A in and over 100W out.
> > > Jan/pa3abk
> > >
> > >
> > > Op 7-12-2010 11:33, Horst St=C3=B6cker schreef:
> > > > Hello,
> > > > I am looking for a power supply 24V/10A. Swiching power supply wou=
ld
> > > > be the best choice to me.
> > > > I got a new PA unit for my beacon DI2AN, but without power supply.
> > > > Power can also be higher (up to 48V).
> > > > vy73 Horst DO1KHS/DI2AN
> > > >
> > > >
> > >
> > >
> >
> >
> >
>=20
>=20