Adelaide 2m.jpg
Interesting 144 MHz Spectral captures
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VK6ZRY
Re: Interesting 144 MHz Spectral captures
just looks like intrastate aircraft reflections, in your path.
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VK2KRR
Re: Interesting 144 MHz Spectral captures
Just posting this up for Colin VK5DK who is testing new 2m beacon VK5RSE
- VK5RSE 2m beacon test
Re: Interesting 144 MHz Spectral captures
The pic you have shown shows S/N in excess of 30dB, perhaps 35dB. If your effective noise bandwidth in SL was say 0.5Hz, then S/N in 2kHz would be around 0dB... plenty good enough to copy the Morse ident that occurs during the fuzzy bits. Could you read the Morse ident?VK2KRR wrote:Just posting this up for Colin VK5DK who is testing new 2m beacon VK5RSE
If the signal was 20dB weaker, you would still have an obvious spectrum trace, but you would not be able to identify the signal using its Morse callsign (as it would be unreadable).
The new VK1 beacons send a low speed ident as well, which allows identification some 20 to 30dB lower in level than by possible by ear.
Owen
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VK2KRR
Re: Interesting 144 MHz Spectral captures
Hi Owen,
It was 5/1 signal most of the time, I was just showing a copy of the graph to Colin VK5DK (and anyone else interested) so he could see how stable and clean the TX was looking on test, as the TX is now set up with GPS ref lock. Its looking quite good from what I can see.
It was 5/1 signal most of the time, I was just showing a copy of the graph to Colin VK5DK (and anyone else interested) so he could see how stable and clean the TX was looking on test, as the TX is now set up with GPS ref lock. Its looking quite good from what I can see.