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Power budgets.




Hello folks,
                For those that don't understand power budgets on satellites -
especially ailing ones - *PLEASE* make the effort to read up on the
subject - so you can honestly say "your" operating *DIDN'T* shorten a
particular satellites life ... or ... you were *NOT* being an alligator
... (all mouth and no ears) ... and using more than your fair share of
the available power.

Remember ... there are potentially many !!
users on AO-7 and the available power is distributed among them ... a
LINEAR transponder isd *NOT* like an FM transponder.

There is an
excuse for simply "not knowing" - but there is no !! excuse for knowing
and ignoring the facts - that's just plain anti-social.

If you're not aware of it, do please !!! take the time to read up on the subject.

73 John   <la2qaa@amsat.org>

From: la2qaa@hotmail.com
To: w7lrd@comcast.net
CC: eu-amsat@yahoogroups.com; allan_gm1sxx@hotmail.com
Subject: Oh - my - God - (AO-7 uplink power).
Date: Fri, 1 Feb 2008 09:41:04 +0100
.......................................................................................

Oh - my - God!,

>On 70cm I run about 80-100 watts to a 40 el cp 
>yagi.  I can pick up my down link when the sat 
>is about 7 degrees.

73 Bob W7LRD 
.........................................
Wow!, 
           That's not an AO-7 satellite class station Bob, it's an EME station. 

Have you not read the recommended operating proceedure for AO-7 !!.

<http://www.planetemily.com/ao7/ao7log.php>

5
watts or less to a decent aerial is adequate. Personally, I have
*NEVER* used more than 5 watts to a homebrew 6 element yagi but this
gave me 3rd place worldwide - (currently 5th) - when I was more active.

I
have taken the liberty of CC'ing part of your mail to the EU amsat
reflector because like me - they won't believe! the power you're using
... 100 watts to 40 elements is several kilowatts !! EIRP.

I
would respectfully suggest you do some research about *WHY* one should
maintain a reasonable power budget when operating satellites ...
afterwards - (hopefully) - you'll see what I mean.

AO-7 is not
in the best of health at at the best of times but hitting it with so
much uplink power is most certainly not going to prolong it's life.

It is also thoroughly recommended to use a "receiver" with an aerial attached - though with your uplink power - (if it's true) -
a wet shoelace ought to suffice.

NB.

You did say 40 elements ... did you mean 4 ???.

73 John.   <la2qaa@amsat.org>
......................................................................................

> From: w7lrd@comcast.net
> To: AMSAT-BB@amsat.org
> Date: Fri, 1 Feb 2008 03:58:29 +0000
> Subject: [amsat-bb]  antenna attenuation
> 
> Hello
>
Has anyone encountered this situation- My satellite antennas are about
15 feet off the ground. approximatly 18 feet away at that height is the
base of a 25 foot tripod that holds my HF quad. When aiming at a
certain direction about 15-20 degrees I can't seem to get through to
AO-7. I am trying to connect with OH8MBN. Other directions I can
usually hear my downlink almost down to the horizon. On 70cm I run
about 80-100 watts to a 40 el cp yagi. I can pick up my down link when
the sat is about 7 degrees.
> 73 Bob W7LRD
> Seattle
> 
> --
> "if this were easy, everyone would be doing it"
> __________________________
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