Message-ID: <002401cb962b$8dd99c40$0401a8c0@xphd97xgq27nyf>
From: "mal hamilton" <g3kevmal@talktalk.net>
To: <rsgb_lf_group@blacksheep.org>
References: <34B6B123BCCD45749F47DE8CDEF8225A@ns94d01ae4d850> <4CFE043E.30609@online.fr> , <896D62DB781D4F0CA8CC2DB3479399A3@ns94d01ae4d850> <1285386885.3721767.1291717992842.JavaMail.fmail@mwmweb079> <4CFE1E26.1030903@kpnmail.nl> <1291728984.1600.15.camel@gerhard-desktop> <001601cb9617$35c861d0$0401a8c0@xphd97xgq27nyf> <1291737904.1637.15.camel@gerhard-desktop>
Date: Tue, 7 Dec 2010 16:26:51 -0000
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Subject: Re: LF: Searching for Power Supply 24V/10A
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Gerhard
If you lived near me I have plenty of surplus transformers hi current=
 from
12 to 50 volts also another point to consider,  a linear psu can be
controlled by a variac on the primary to adjust the voltage to that re=
quired
whereas a smpsu can not.
The only advantage of  a smpsu is the small size and light weight.
Interference could be a problem.
I also have lots of hi voltage transformers up to 1500 volts at around=
 1
amp for tube amplifiers.
I am also using vintage xtals at least 60 yrs old for both 137 and 500=
 Kcs
and steady as a rock after all these years !!! ex military surplus
Probably out of a Lancaster of a B17 bomber!!


73 and gl de mal/g3kev

----- Original Message -----
From: "Gerhard Hickl" <gerhard.hickl@aon.at>
To: <rsgb_lf_group@blacksheep.org>
Sent: Tuesday, December 07, 2010 4:05 PM
Subject: Re: LF: Searching for Power Supply 24V/10A


> 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 highe=
st
> 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
capable
> > 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
> >
> > ----- 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
> >
> >
> > > 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 disconne=
cting
> > > the earth from chassis!!!) and connect the 12V supplies in serie=
s.
> > >
> > > 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
feeders.
> > > > 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 wa=
s
rather
> > > > 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 supp=
ly
would
> > > > > 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
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> > >
> >
> >
>
>
>