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Re: AO40 U-AGC question



On Tuesday 15 July 2003 2:03 pm, Estes Wayne-W10191 wrote:
snip
>
> I'm curious what your downlink antenna is, and what percentage of the
> stations you contact considered your 5W uplink to be "easily copied".  I'm
> sure I could get Q5 copy of your signal under ideal conditions, even though
> your signal is probably 12-13 dB below the beacon under the best of
> circumstances.  Unfortunately, I rarely have ideal conditions this time of
> year because of tree obstructions.  I have no doubt that a LOT of AO40
> stations won't answer you because they can't hear you well enough to have a
> pleasant conversation.
>
> Even with my 2-foot dish (patch feed, low noise preamp) I hear stations on
> AO40 who are significantly more deaf than me.  It's a fact of life on AO40,
> especially because there is no downlink that penetrates trees.  Some of the
> "deaf" stations may have GREAT receiving setups, but just have tree
> obstructions at that time.
>
> Since you are so knowledgeable about the AGC subject, I'm curious what
> motivated you to operate with 5W during Field Day.  You knew very well that
> the AGC would be seriously affected.  It's a lot of work to put together a
> Field Day satellite station.  I wouldn't go to all that trouble to put
> together a Field Day station that I knew in advance wouldn't be suited to
> the expected operating conditions.
>
> Wayne Estes W9AE
> Mundelein, IL, USA
> ----


Wayne,
lets stop and look at this....

you acknowledge that  YOU have a problem...
 "Unfortunately, I rarely have ideal conditions this time of year because of 
tree obstructions"

so how do you respond to YOUR problem.... you run more power....  so now the 
trees are not a problem for you but your banging the AGC is a problem for 
everyone else....

A better response would have been ... I have a problem... TREES... so I have 
put a larger dish than would be normally needed to compensate for MY 
limitations...   

get the picture???


     I have a clear shot from the top of my roof and I run a 3 foot dish with 
a g3ruh patch with a db6nt DC ... pretty good stuff... and I consider the 3 
foot dish OK when squint is low... when the squint is high I have a 6 foot 
dish in the back yard...  the 6 foot dish is overkill but I did not want my 
receive to be my limiting factor...

The point to all of this, if your hearing of the sat good  i.e. "you hear the 
noise floor..."  you don't need much power, sometimes less than a watt is a 
good QSO and 2 watts is gravy.... low power by all, means no AGC.... no AGC 
means no fades.... 

   I have been on AO40 enough to know that it was going to stink on field day 
because I KNEW everyone would drag amps and big antennas for transmit and 
then bring a foil lined cardboard P.O.S. or something worse for receive  and 
then blast away.... and once you get a couple doing that then the AGC goes up 
signals go down and everone cranks up... and there you have it... solid high 
AGC for the entire pass...

When will anyone learn that with this sat in the mode its in right now...  
this little receive big transmit caca ain't gonna cut it......


73
Kevin 
WA6FWF

 



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