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Re: ERP on V and L for AO-40 (Shouldn't this be mode U and L?)??





  In addition to whatever power is required to 
work the uplink at its theoretical best,  don't forget
to add a sufficient reserve to allow for wet foliage/antennas,
antenna pointing deficiencies (my tx & rx antennas are always
slipping out of relative alignment) and non-favorable squint angles.

  I would imagine having a reserve of 6-10db would not be
unreasonable to allow for 'real world' operating conditions,
and the higher demands of any upcoming digital modes.


  (A similar margin on recieve would of course be required,
since all these factors will degrade the downlink  more
severely than the uplink.)


  -sl
  WB1BQE



Gary \"Joe\" Mayfield wrote:
> 
>       I would argue that 25 W ERiP is completely unrealistic at appogee.  I
> have made my share of AO-40 contacts, and my setup is as follows.  My FT-847
> gets about 25 Watts at 435 MHz  (50 Watts at 432 and 50 Watts at 446.00,
> just my luck!).  I have about 50 feet of LMR-400 UF coax,  I should loose
> less than 2 dB there, but I am going to say I loose 3dB to be safe.
> Cushcraft claims I have a 12 dBi antenna (RHCP), so I will say it is
> probably a 9 dBi antenna.
> 
>      My result is 25 Watts into 6dB of system gain or 100 W ERiP.  In
> reality it is probably a little more than that.  I am one of the weakest
> signals on the bird.  Leila is completely unaware of my existence (I would
> like to trip her once just so I could say I did!).  I often will answer CQs
> and the calling station doesn't hear me (I can hear myself so I know I'm on
> frequency).  In my opinion a 200 W EiRP is needed for reliable SSB
> communications.  I do not think LEILA will notice you untill you are well
> above 600 W EiRP.  I believe most of the good signals we work (easy copy,
> but not tripping LEILA or the AGC) are probably right around the original
> design spec of 400 W EiRP.
> 
> Just My Opinion,
> Joe
> ka0yos@amsat.org
> 
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