20 Jul
2009
20 Jul
'09
10:19 p.m.
Hello Philipp,
On Mon, 20 Jul 2009 18:39:47 +0200, "dexter" <zero-kelvin(a)gmx.de> wrote:
We have a Toy-Spectrum-Analyser here, so i have measured the output of
our BS-11 when initalized with -f 123
http://www.root.runningserver.com/pub/openbsc_spektralanalyse.png
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.
I don't know what the specification for a BTS allows as level for
emitting on other frequencies, so I can't give you any numbers how
strong those other signals can be.
Best regards,
Dieter
--
Dieter Spaar, Germany spaar(a)mirider.augusta.de
20 Jul
20 Jul
8:49 p.m.
New subject: Spectrum analysis shows strange carrier
Hello Dieter,
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.
I think that is the most plausible explaination. The antenna of the
spectrum analyser was positioned very close to the BS11. That might be a
reason why unwanted Signal comes out so strong.
besides: An expert told me that the grounding in our laboratory is not
so good at all. That also might weak the shilding.
Thanks!
regards.
Philipp
9:49 p.m.
New subject: Spectrum analysis shows strange carrier
ok there are only downlink signals there since it s more than 935MHz.
If I understand one of the pike 1&2 vanishes when you stop the BTS and the
other one stays? Or is it the 3rd pike at 959.6 MHz who vanishes?
I am not sure but I think you said the pike 1 disapeared and the pike 2
(weaker) staid... right? and the 3rd pike?
The pike at 959.6 MHz corresponding to n = 123 is coming from the Tx0 for
sure as Dieter said.
Can you say what you can see when you load the bs11 with bs11_config query?
And which power did u setup? 30mW (default)?
Best regards,
Eric
2009/7/20 Dieter Spaar <spaar(a)mirider.augusta.de>
Hello Philipp,
On Mon, 20 Jul 2009 18:39:47 +0200, "dexter" <zero-kelvin(a)gmx.de> wrote:
We have a Toy-Spectrum-Analyser here, so i have measured the output of
our BS-11 when initalized with -f 123
http://www.root.runningserver.com/pub/openbsc_spektralanalyse.png
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.
I don't know what the specification for a BTS allows as level for
emitting on other frequencies, so I can't give you any numbers how
strong those other signals can be.
Best regards,
Dieter
--
Dieter Spaar, Germany spaar(a)mirider.augusta.de
5401
days inactive
5401
days old
2 comments
3 participants
participants (3)
-
Dieter Spaar -
Eric Cathelinaud -
Philipp Fabian Benedikt Maier