[TenTec] Orion SWR protection

[Carl Moreschi]

The finals can take  25 amps times 14 volts of heat dissipation.  It's that
simple.

Carl Moreschi N4PY
Franklinton, NC
----- Original Message -----
From: "Mike Hyder -N4NT-" <N4NT_Mike.Hyder at charter.net>
To: <tentec at contesting.com>
Sent: Friday, May 09, 2003 2:26 PM
Subject: Re: [TenTec] Orion SWR protection


> Limiting PA current limits PA input power.  But output power can vary with
> the load impedance.  Since the dissipation is the PA difference between
> these, it would seem that limiting the current would not be sufficient
> protection except short-term.  Where is my thinking going wrong?
>
> 73, Mike N4NT
>
> ----- Original Message -----
> From: "Carl Moreschi" <n4py at earthlink.net>
> To: <tentec at contesting.com>
> Sent: Friday, May 09, 2003 10:09 AM
> Subject: Re: [TenTec] Orion SWR protection
>
>
> > The Orion has protective circuitry to limit the current in the finals to
a
> > safe value. There is no point where SWR "fold back" occurs.  It just
won't
> > let the current in the finals get too high.  This is an excellent
> protection
> > method.
> >
> > Carl Moreschi N4PY
> > Franklinton, NC
> > ----- Original Message -----
> > From: "Pete Smith" <n4zr at contesting.com>
> > To: <tentec at contesting.com>
> > Sent: Friday, May 09, 2003 12:35 PM
> > Subject: Re: [TenTec] Orion SWR protection
> >
> >
> > > At 05:33 AM 5/9/03 -0400, you wrote:
> > > >The specification of "25 amperes" covers ORION's performance under
all
> > > >specified
> > > >conditions, but if your antenna impedance is between 50 and 100 ohms,
> > > >including
> > > >moderate reactance, a 22-ampere power supply will run ORION at close
to
> > > >full power. If
> > > >you must have full power under all specified conditions, ORION needs
25
> > > >amperes.
> > > >
> > > >         Simple answer is, full rated power at SWR 2.0:1 and below.
> > >
> > > This looks suspiciously like a similar statement in my Mark 5 manual,
> but
> > > the Mark 5's protection kicks in rapidly and rather below 2:1
indicated,
> > > while that in the TS-930 comes into play more gradually.  I guess I
> could
> > > have asked the question better -- how aggressively does the Orion
> ACTUALLY
> > > reduce the output power as the SWR approaches 2:1, and what part does
> > > reactance play in that?  Presumably, it isn't just a question of
25-100
> > > ohms resistive... what is "moderate reactance," to borrow the term
used
> in
> > > the manual?
> > >
> > > 73, Pete N4ZR
> > > The World HF Contest Station Database was updated 11 April 03.
> > > Are you current? www.pvrc.org/wcsd/wcsdsearch.htm
>
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