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Old 06-05-2015, 23:43   #46
mitajohn
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The CIR turned better and I got audio. Except of a TX break down the rest was almost perfect.
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Old 07-05-2015, 06:48   #47
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I noticed the break too.
Perfect otherwise
It seemed to me that the signal was slightly stronger after the break.
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Old 07-05-2015, 08:47   #48
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Last night's transmission was again a success. Including the short TX failure around 1932 UTC the decoded audio for the whole transmission was 99.35%. The DRM configuration was the same as the night before. 8.08 kbps gives 3000 Hz audio bandwidth, but the audio was relatively pleasant anyway.
I noted a new record of max. 29.24 dB SNR at 21:35 UTC. The average SNR for the transmission was 24.13 dB. Both values would have been slightly better if there hadn't been the TX break.

The latter part of the log was unattended. The CIR improved slightly during the evening.
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Old 07-05-2015, 18:35   #49
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Like Alan mentioned, there is a data churner around 7557 kHz now at 1730 UTC, but it ought to be outside AIR's DRM spectrum. More later.
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Old 07-05-2015, 19:40   #50
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Quote:
Originally Posted by mitajohn
... SODIRA sw shows a sample rate of 12 kHz? is this correct?

John,

I can't explain it, just verify it - my SoDiRa shows 12000 Hz too.
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Old 07-05-2015, 20:22   #51
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Like Alan and Terje mentioned, there is a data churner around 7557 kHz here too, outside the DRM spectrum. It seems that it does not affect the decoding, may be only the SNR, but I'm not sure...
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Old 07-05-2015, 21:07   #52
F1BJB
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Same adjacent signal on 7557.
It is weaker and spectrums don't overlap.
For the 12 Khz sampling rate it is not a default and allows a 6 Khz theorical audio bandwidth reduced to 3Khz in practice by the 8Kbps codec used.
In fact the real question is why do some DRM signals use a 48Khz
sampling rate.
Sodira doesn't allow listenning to the second audio channel only Dream
can do it and for some strange reason Dream 1.6.1 works better than
Dream 1.17 here.
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Old 07-05-2015, 21:13   #53
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Quote:
Sodira doesn't allow listening to the second audio channel only Dream can do it

Not quite correct, DRM Software Radio 2.0.38 allows too.
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Old 07-05-2015, 22:49   #54
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... neither does the DR111 from Newstar. I can see both services in the submenu, but only the Regular Service is possible to decode. I tried my DRM Software Radio 2.0.38 too.

Regarding DReaM, I also tend to stick with the 1.6.1 cvs although I have collected different versions during the years. But 1.6.1 sometimes won't work on Journaline.

On 7550 DRM Software Radio 2.0.38 says "Text 80 bps" on both Regular Service and Test Music, but something crashed (see picture). John?
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Old 07-05-2015, 23:13   #55
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Terje, it works fine here...
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Old 07-05-2015, 23:22   #56
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AIR 7550kHz

The usual good strong signal into the UK this evening on 7550kHz.
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Old 07-05-2015, 23:46   #57
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Strong signal >60dBuV, decoding problems started after 21H20 and SNR dropped.
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Old 08-05-2015, 06:42   #58
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Perfect reception even when the Doppler started to vary after 2025 UTC. Max SNR was 29.94 dB at 2138. The dip shortly after the max. SNR could have been caused by my PC during my tests with the DRM Software Radio.
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Old 08-05-2015, 20:07   #59
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An early TX shut down ?
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Old 08-05-2015, 20:26   #60
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Yes, though why I'm not sure. I was just listening to it as normal when it suddenly vanished. Maybe just a technical problem, so I'll leave the decoder running for a while and see what happens.
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