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Re: My 'First AO40 FD ' question



Hi Greg,

I can only relate my experience a few years ago on AO-10 during FD.  It
sounded like 20m!  There were so many stations on that the weak ones were
having difficulty being heard.  Now AO-40 is different due to LEILA.  I use
a big UHF yagi (18-foot with 16.5 dBd gain) and find at times I need my
full 50w.  Usually this is when squint is high and activity high (and
alligators on the bird).

I would expect a good turnout if there is a good orbit window during FD.
If so you may find a small UHF yagi and 10-15w not enough for ssb.  If you
use a 10-12 element yagi I would try to have an adjustable power up to at
least 50w.  That will get you 500 to 1000w EIRP.  Normally, I would say
having 150-200w EIRP is adequate.  Glad to hear you have a good hearing
system, but realize that some FD stations will not hear well because: 1)
they are using inadequate dishes and equipment and/or 2) the are trying the
satellite for the first time (newbies).

I hope most who do try FD prepare ahead of time and get some experience
operating.  AO-40 is not like throwing up a wire and operating on 20m ;-)
Yet I am guilty of trying to work a LEO sat in FD with no practise...total
failure (years ago).

GL, Ed - AL7EB

At 10:34 PM 5/20/03 -0700, you wrote:
>I'm preparing for my first AO40 FD with new portable antennas, hoping to 
>uplink  with my FT847 and a 14 element CP GulfAlpha antenna on 70 cm.
>
>June's QST suggests at least 100W uplink power to an 11 element (or 
>more) antenna for mode U/S operation, because Field Day is 'not like any 
>other weekend'. This has me wondering exactly HOW much activity there 
>might be! All I have is the AO40 QSO party to compare to. Is FD busier? 
> Is the minimum 100W uplink power an exageration?  Elsewhere I've read 
>'you better bring along your key' if you expect to make contacts without 
>alot of power.
>
>Bye the way, I believe my downlink portable system will be sensitive 
>enough to compare with my base station. (1 meter P* dish, 0.9 NF 
>downverter)  I think I will hear the bird fine.
>
>Should I expect it to be a struggle to make voice QSO's due to 
>congestion, or AGC levels?
>
>Any realistic advice appreciated!
>
>K7YDL
>Greg
>
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