Re: [amsat-bb] Calling SO-41, can you hear me ?

[Emily Clarke <emily@xxxxxxxxxxxxxxx>]

Hi Ron,

I don't know about running 50 watts ERP that seems high to me.  But it's 
possible. I was running about 10W into a 9db yagi today when I worked 
it.   And you won't get that with any Arrow and a W32 - here's why:

Icom W32 on 9.6V Battery Pack:  ~3.5W  (3W on 7.2V Battery Pack)
Estimated maximum gain of 3ele Arrow 2m Antenna  7db (probably more like a 
standard 3 ele yagi - 5db)
7db = 4.92 x 3.5W=17.3W ERP

Even with a 12V power source, the Icom will put out 5W and your ERP would 
be ~25W - 25W short.

My ERP was about 80W.

One other thing I have noticed (and have to track down on my end) is that 
the SaudiSat birds seem to run narrow FM.  This means that you probably 
need to correct more precisely on your transmit frequency than you would 
for UO-14.   Either that and/or my FM IF stage is slightly off frequency 
which I won't be able to check until later today.  I didn't seem to get 
into the bird until I tuned my tx for doppler.  Alternatively I could have 
the incorrect frequency, but I think it is the same as SO-50.

Hope this helps!

- Emily



At 04:35 PM 8/31/2003 -0400, you wrote:
>I tried both passes this afternoon and could hear SO-41 clearly but couldnt
>get anyone to respond to me.  I am using my trusty ICW32 icom handheld and
>Arrow dual band beam that worked on UO-14 and works on SO-50 when it is on.
>I reviewed the Amsat red cover satellite book and found the note that I need
>to be running around 50 watts ERP to use SO-41.  Since Al @ Arrow hasnt been
>able to provide any dB gain figure for his antennas, I am running blind.  I
>think it is safe to say that the antenna probably doesnt have over 2 to 3 db
>of gain.  Correct me if this figure is wrong.
>
>This means that I will need to get some type of amp to be able to use the
>handheld.  Any suggestions ?
>
>Ron
>Ka4kyi
>
>
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