[Elecraft] Power Supply?

[Edward R. Cole]

Another example of "reading the manual" or in this case the "info sheet".

I have run Basecom20 for a 50w VHF-FM radio for up to ten years 
onboard 200-foot oil field work boats.  I did have one "croak" but 
that might have been due to the highly regulated (joke) ships 
generator: 115vac +/- 50vac!  Ten years in continuous duty is not 
bad.  These look to be re-labeled Astron RS-20 PS and have been 
supplying multiple radios on a boats.  250w => 18 amps.  A 150w 
marine SSB will have a dc load of about 250w.

I use a 50A Tait PS (14.1 vdc) to power my home station 12volt 
needs.  The No. 6 welding wire supply line is fused at 30A at the 
radio table distribution point.  Been in service for about 9 
years.  This is a re-labeled Astron VM-50.

So, yes, I derate them about 60% for long-term service.

Ed - KL7UW

At 06:16 AM 7/3/2011, Eugene Balinski wrote:
>All,
>
>    Please be advised that Astron supplies are generally
>over rated.  The RS-20 is rated at 20A peak and 16A
>continuous.  It is more like 12 -14 continuous.  I have
>seen people try to use them at their "continuous" ratings,
>only to have them fail.  The heat sinking is just not
>there.  Be careful when using any of the supplies at their
>top ratings.  If you need to use one at rated, then put a
>good fan on the heat sink.
>
>
>73
>K1NR
>
>
>
>On Sun, 03 Jul 2011 00:17:46 -0800
>  "Edward R. Cole" <kl7uw at acsalaska.net> wrote:
> > I sure Elecraft can answer this better.  I would make a
> > guess that
> > power supplies in much equipment is bought from a vendor
> > and
> > installed as a module; the vendor having taken care of
> > all necessary
> > certifications.  Perhaps in high volume production the PS
> > is ordered
> > to the manufacturers spec but supplied by a vendor the
> > makes power supplies.
> >
> > The Basecom20 is sold by Motorola but it is identical to
> > the Astron
> > R20.  My guess Motorola contracts Astron to manufacture
> > the power
> > supply re-labled for Motorola to sell.
> >
> > When I was making custom equipment I didn't build the
> > power supply as
> > it was cheaper to buy something off-shelf at wholesale.
> >
> >
> > 73, Ed - KL7UW, WD2XSH/45
> > ======================================
> > BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
> > EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-?
> > DUBUS Magazine USA Rep dubususa at gmail.com
> > ======================================
> >
> >
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73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-?
DUBUS Magazine USA Rep dubususa at gmail.com
======================================