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Re: UO-11 Beacon



I appreciate Domenico's information about UO-11. I became so frustrated not
being able to hear the AO-40 beacon that I removed the 2.4 GHz antenna and
downconverter. I'll put it back up and try to hear the strong UO-11 signal,
and I also need to come up with a local 2.4 GHz signal source.

Again, thanks Domenico.

Mike
K9QHO
AMSAT 33589

----- Original Message -----
From: i8cvs <domenico.i8cvs@tin.it>
To: ken durham <kendurham@home.com>; AMSAT-BB <amsat-bb@AMSAT.Org>
Sent: Wednesday, July 04, 2001 6:44 PM
Subject: R: [amsat-bb] UO-11 Beacon


> Hi  Ken,
>
> The nominal UO-11 beacon frequency is 2401.505 MHz  at TCA or time of
> closest approach.
>
> At AOS or aquisition of  signal you must look and tune approximately 50
KHz
> higher  in frequency for Doppler i.e. at 2401.555 MHz
>
> At LOS or lost of signal  the frequency  will appear approximately 50 KHz
> lover for Doppler  i.e. at 2401.455 MHz
>
> In total the rate of chage of  frequency for Doppler is about 100 KHz in a
> pass and you have to tune the carrier continuosly at a rate of about  6
> KHz/min at TCA
>
> Try to tune your IF  from around  145.555 MHz  at AOS to 145.455 MHz at
LOS
> because in a LEO satellite the frequency  is always higher than nominal
for
> Doppler as soon you get the aquisition of  signal  i.e. + 50 KHz in this
> case.
>
> The UO-11 beacon is very strong and it is a very good reference to
evaluate
> the S band receiver performance time to time.
>
> 73 de i8CVS Domenico
>
> ----- Original Message -----
> From: ken durham <kendurham@home.com>
> To: <amsat-bb@AMSAT.Org>
> Sent: Wednesday, July 04, 2001 10:55 PM
> Subject: [amsat-bb] UO-11 Beacon
>
>
> > Well, using the UO-11 beacon for a signal source doesn't work for me
> either. It just went
> > nearly overhead and I couldn't hear anything
> > near 2401.500. Guess the system isn't near good enough for AO-40
> > yet. Got a .7dB NF primp ordered from Down East Microwave. Maybe
> > this will help enough. Maybe a helical feed on the BBQ dish might
> > give some improvement too. At this point, I don't know how far
> > the LO is off in the Drake downconverter. The IF is at 145 MHZ for
> > 2401 MHZ input and the NF is supposed to be tested at 3 dB. Don't
> > have a way to calibrate either one. Wonder if there is a local HAM
> > who could xmt on 2400?
> > Ken K5MBV Garland, TX
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>
>
>
>
>
>
>
>
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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>

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