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CX2SA > SATDIG 21.04.10 20:06l 159 Lines 4451 Bytes #999 (0) @ WW
BID : AMSATBB5182
Read: GUEST
Subj: AMSAT-BB-digest V5 182
Path: IZ3LSV<IW0QNL<F4BWT<F4DUR<CX2SA
Sent: 100421/1904Z @:CX2SA.LAV.URY.SA #:54945 [Minas] FBB7.00e $:AMSATBB5182
From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: XE1AO @ DK88 on AO-27 today (Rafael Valdez G.)
2. Re: Arecibo on 432 MHz Moon Bounce (some calculations) (i8cvs)
3. AMSAT-TAPR Banquet (Martha)
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Message: 1
Date: Wed, 21 Apr 2010 10:36:31 -0700
From: "Rafael Valdez G." <rafavaldez@xxxxxxx.xxx>
Subject: [amsat-bb] Re: XE1AO @ DK88 on AO-27 today
To: <amsat-bb@xxxxxx.xxx>, <amsat-bb@xxxxx.xxx>
Message-ID: <BAY111-W92D62337EE28CFDAAEB53DB090@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
> Omar did not mention if he would use his normal call or
> 4B1AO with the special prefix XE hams are allowed to use this
> year.
>
He will be using 4B1AO
Good luck everybody.
Rafael / XE2RV / DM41mh
_________________________________________________________________
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Message: 2
Date: Wed, 21 Apr 2010 19:49:23 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: "Fabio A" <iw8qku@xxxxx.xxx>, "AMSAT-BB" <amsat-bb@xxxxx.xxx>,
"Mateusz" <sq7dqx@xxxxxx.xxxx.xx>, "G8IFF/KC8NHF Nigel A. Gunn"
<nigel@xxxxx.xxx>
Message-ID: <00a601cae17a$faced880$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "Fabio A" <iw8qku@xxxxx.xxx>
To: <AMSAT-BB@xxxxx.xxx>
Sent: Tuesday, April 20, 2010 8:26 PM
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some calculations)
> Hello all,
> just a curiosity, how did you found that the ERP is "... 243,902,443
> Million Watts".
>
> Thanks
>
> 73s
> Fabio
> iw8qku
>
Hi Fabio, IW8QKU
The only official data given for Arecibo by WF1F are the following :
> The 1,000 foot dish has 60 dBi on 432 mc and 400 watts.
> That comes out to be approximately 243,902,443 Million Watts ERP.
>
> enjoy
>
> wf1f
To answere your question:
"how did WF1F found that the ERP is "... 243,902,443 Million Watts".
THERE ARE TWO POSSIBLE OUTCOMES:
Outcome Nr 1 or first possibility:
Since the given ERP is 243,902,443 Million Watts (see the WF1F above
statement ) and since 60 dB is equivalent to 1000000 (one Million) time
in power it comes out that the power reaching the feed of the dish must be:
243902443 / 1000000 = 243 watt
The rest of the power 400-243 = 157 watt must be losted in the feed line
because the 400 watt amplifier is non mounted inside the feet but there
should be a feed line long half the diameter of the dish from the feed and
the operating point made of low loss big coax cable almost 150 or 200
meters long wich attenuation is 10 log (400/ 243) = 2.16 dB
10
Outcome Nr 2 or second possibility:
The 243,902,443 Million Watt ERP has been calculated in a wrong way
considering the gain of the dish not 60 dBi or 60 dB over the isotropic
antenna but 60 -2.14 = 57.86 dB wich is the gain over the dipole or
57.86 dBd and infact the wrong calculation showes:
10^ 5.786 = 610942 Million time in power and
400 watt x 610942 = 244,376,810 Million Watt ERP wich match very
close with the value " 243,902,443 Million Watt" given by WF1F but it
is a wrong value because it has been calculated with a gain of 57.86 dB
instead of 60 dB
In order to know the real numbars a more informative clearification from
the Arecibo Observatory Amateur Radio Club is welcome and necessary.
I hope this helps
73" de
i8CVS Domenico
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Message: 3
Date: Wed, 21 Apr 2010 14:14:33 -0400
From: Martha <martha@xxxxx.xxx>
Subject: [amsat-bb] AMSAT-TAPR Banquet
To: AMSAT BB <amsat-bb@xxxxx.xxx>, Board of Directors <bod@xxxxx.xxx>,
senior-officers <senior-officers@xxxxx.xxx>
Message-ID:
<u2j956751cf1004211114yd170283fyb6e2a3311cb2e996@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Please be advised that tickets for the AMSAT-TAPR banquet at Dayton will not
be sold at the booth. All tickets must be purchased at the AMSAT store
found on the AMSAT website.
--
73- Martha
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End of AMSAT-BB Digest, Vol 5, Issue 182
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