[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Not QRP on L-band!!



    My 1.8 meter dish is rated at 24.6 dB circular.  I calculate 1,445 watts
EIRP is the estimate so I confirm and agree with you it is about 1.5 Kw.
    I ran these figures in the AO-40 Ground Station Evaluation tool and I
see that there are cases during low squint angles where I could produce an
uplink that would be greater than -10dB from the beacon level.  I don't see
cases during normal operating conditons where I would equal or exceed the
beacon level.
    If the definition of too much power is -10dB below the beacon then I
agree that I could exceed that threshold with this setup.
    I stand corrected !  Hi.  Thanks for the feedback.

    Best regards,
    Jim KL7QR Phoenix Arizona


----- Original Message ----- 
From: "Scott Townley" <nx7u@cox.net>
To: "Amsat Mailing List" <amsat-bb@AMSAT.Org>
Sent: Friday, August 22, 2003 11:33 AM
Subject: [amsat-bb] Not QRP on L-band!!


> Sorry Jim, have to disagree.
> 5W may be "QRP", but 5W to a 1.8m dish is NOT QRP.  That's 1.5kW EIRP or
so, which is well above the recommended few-hundred-watt category.
> Power is irrelevant...EIRP is everything.
>
> >
> > From: "Jim Tudehope (Peoria Arizona)" <jtudehope@cox.net>
> > Date: 2003/08/22 Fri PM 01:22:11 EDT
> > To: "Amsat Mailing List" <amsat-bb@AMSAT.Org>
> > Subject: Re: [amsat-bb] working split on DXpeditions
> >
> > " Wayne replies:
> >
> > L-band uplinks aren't notched by LEILA, but the loud siren is still
there.
> > I would argue that you are running TOO MUCH UPLINK POWER if your voice
is Q5
> > copy on top of the LEILA siren.
> >
> > Wayne Estes W9AE
> > Mundelein, IL, USA
> > "
> >
> >     Jim - KL7QR responds ...
> >
> >     In my case I use just 5 watts on L mode with a 1.8 meter dish and I
can
> > be heard through LIELA.   I respectfully disagree based on practical
> > experience.
> >     Your premise:  IF ( a station can be heard Q5 through LIELA on L
mode)
> > THEN ( they are using too much power ) is false.  Therefore any
conclusion
> > of any arguement that uses this mistaken premise is also false.
> >     I have had several situations on the air where I was Q5 through
LIELA
> > even though I am a QRP station.  It may not be 100% of the time but
often
> > this is true in the SSB mode.
> >     I would venture to say if I were to operate in the CW mode the
receiving
> > stations would have even more success copying my QRP signal through the
> > LIELA.
> >     I think if a DXpedition were to operate split in the L mode it would
> > work better than if they were in U mode.  I think that if LIELA was
> > triggered by the U band uplinkers then I would still be heard often
times Q5
> > while always using acceptable power levels on L mode.
> >     Practical case in point.   On the 19th of July 2003 12:13 GMT there
was
> > a pileup on station HK3GAL Ger from Bogota Columbia.  There was lots of
U RX
> > AGC receiver attenuation causing "QSB"  from the number of U band
uplinkers
> > trying to call this station.  I made one call using 5 watts on L mode
and
> > got him the first try.
> >     My conclusion is that L mode works better.  You can often times
> > outperform U band uplinks with just a fraction of the power.  My guess
is
> > one major reason is the L1 RX AGC attenuation is often less than 1 dB
while
> > the U RX AGC attenuation is always much higher.
> >
> >     Best regards,
> >     Jim KL7QR / 7
> >     Phoenix Arizona DM33up
> >
> > Jim Tudehope
> > 10553 W. Sands Dr.
> > Peoria, Arizona, 85383
> > Phone: 623-566-9955
> > Fax: 602-650-0669
> > T. Inc. http://www.tudehope.com
> > Ham Station KL7QR:  http://www.members.cox.net/jtudehope/KL7QR.htm
> >
> >
> >
> >
> > ----- Original Message ----- 
> > From: "Estes Wayne-W10191" <W10191@motorola.com>
> > To: <amsat-bb@AMSAT.Org>
> > Sent: Friday, August 22, 2003 8:22 AM
> > Subject: Re: [amsat-bb] working split on DXpeditions
> >
> >
> > > I wrote:
> > >
> > > There is one major problem when a DX station works split-frequency on
> > AO40.  The station calling the DX station never knows when LEILA is
notching
> > his uplink.
> > >
> > > Then Rick KG6IAL replied:
> > >
> > > One more reason to go up on L-band.  ;>)
> > >
> > > Wayne replies:
> > >
> > > L-band uplinks aren't notched by LEILA, but the loud siren is still
there.
> > I would argue that you are running TOO MUCH UPLINK POWER if your voice
is Q5
> > copy on top of the LEILA siren.
> > >
> > > Wayne Estes W9AE
> > > Mundelein, IL, USA
> > > ----
> > > Sent via amsat-bb@amsat.org. Opinions expressed are those of the
author.
> > > Not an AMSAT member? Join now to support the amateur satellite
program!
> > > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> > >
> >
> > ----
> > Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> > Not an AMSAT member? Join now to support the amateur satellite program!
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
>
> Scott Townley NX7U
> Gilbert, AZ  DM43di
>
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>

----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home