Spectrum analysis shows strange carrier

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Dieter Spaar spaar at mirider.augusta.de
Mon Jul 20 21:48:31 UTC 2009


Hello Philipp,

On Mon, 20 Jul 2009 20:19:16 CEST, "Dieter Spaar" <spaar at mirider.augusta.de> wrote:
>
> Not sure what you are measuring on peak one and two, but channel 123
> should be 959.6 MHz, this is most certainly the third peak. There might
> be small signals (e.g. from the oscillator of the BS-11) on other
> frequencies, but they should be much smaller than the main signal.

In the meantime I did check with my spectrum analyzer. There is
indeed a signal coming from the BS-11, even if nothing else is
connected to the BS-11 (no serial connection, no E1). The signal
starts to be emitted after the firmware download is complete.

I could measure the signal at 942.4 MHz, the level is about -42 dBm
(cable connection from the spectrum analyzer to TRX0, low-quality
cable). The signal strength does not depend on the power amplifier
setting, I wonder where it comes from (some internal oscillator
working at that frequency ?). The signal is not very strong, so
it should not cause major trouble (besides disturbing a weak
signal which might be there from an "official" source if you
are close to the BS-11).

Best regards,
  Dieter
-- 
Dieter Spaar, Germany                           spaar at mirider.augusta.de




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