DRM Heard

Here in upstate NY I have heard and decoded to audio Nigeria, Kuwait, Romania, India HF. I have not heard even a trace on WINB or funklust
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Comments

  • DRM has been a real disappointment out here in San Diego. Few stations transmit it, and none of them have been strong enough to decode. Late at night I can regularly see, e.g., China on 6030 kHz or WINB on 7315, but their SNRs are never high enough to decode even with the new AGC fix. There's also co-channel interference from Radio Marti (and its Cuban jammer) on 6030 and from AM stations either on the same frequency or 5 kHz away from 7315.

    There's plenty of North Korean jamming especially on 49m but it doesn't seem to be near any DRM signals.

    BTW, users may have noticed how DRM omits the 0 Hz carrier. That was a very wise move. It buys a little immunity from co-channel AM interference since an AM carrier's power spectral density is so huge compared to its sidebands.

    Does Voice of Russia still exist? I read that they discontinued all shortwave broadcasting several years ago, but they're still listed in the DRM schedule. I have never seen any of them in a waterfall display, though.
  • I was just checking on Inida on 7550 with DRM but the time slot doesn't match the kiwi schedule
  • The Kiwi list is sourced from a number of places. I find that the drm.org and hfcc.org listings are very inaccurate in many cases. Plus the broadcasters sometimes change things frequently. The groups that do have more accurate info (specialty mailing lists, etc.) are often protective of their hard-earned data and have restrictions against re-publication.
  • I'll start adding actual loggings, freq and time here. Maybe others can too and then that info applied to the schedule.
  • jksjks
    edited January 14
    Yes please. Also pointers to authoritative websites having updated schedule info that I can follow (info not subject to use restrictions).
  • edited January 14
    Today 14 Jan @ 1925Z (times align with kiwDRM schedule):
    5995 Romania
    7235 Romania
    7550 India

    Enough SNR to get decode to confirm DRM

    at 2100Z
    6030 Romania
    7550 India

    at 2200Z
    9490 Romania

    2300Z
    6040 Romania
  • BBC DRM active on both frequencies 3955 & 15620, times align with schedule:
  • jksjks
    edited January 15
    These appear as narrow 15-minute slivers in the schedule because although I heard the signal I can't find any schedule info. Anyone know more?
    CNR: 9860, 11850, 13680
    AIR: 9445 (parallel 7550?)
    RNZI: 9780 (not in their online listing)

    Since newdelhi.twrmon.net:8073 is back online I was able to do a band-scan at 6AM local and verify a bunch of India MW DRM. Eleven are now shown verified in the schedule.
  • RNZI DRM changed to unregistered frequency from Jan 1.
    1651-1750 5975 (unchanged)
    1751-1850 11690 (ex 9780)
    1851-1958 13840 (ex 11690)
    https://rnz.co.nz/international/listen
  • All India Radio
    6100kHz and 9950kHz are actually AM broadcasts.
    Instead, DRM broadcasting is performed on the following frequencies that are not registered as DRM.
    1000-1100 15410kHz ch1:English ch2:Music
    1145-1330 15030kHz ch1:Chinese ch2:Tibetan
    https://short-wave.info/index.php
    www1.s2.starcat.ne.jp/ndxc/ (Aoki list)
  • Ron has a screen cap of RNZI on 9780 today (http://forum.kiwisdr.com/discussion/comment/9004/#Comment_9004) and 11690 on Jan 8 (http://forum.kiwisdr.com/discussion/comment/8901/#Comment_8901). So more verification needed. These published schedules are just not well maintained.
    fractional_n
  • 15620kHz BBC
  • edited January 15
    Verified what has been said: Have copied WINB on at least two frequencies (haven't manage to catch the 3rd yet). Although listed as being centered on 7315, 9625 and 13690, it appears that only the upper half of the 10 kHz wide signal actually carries anything and that they are really running a 5 kHz wide channel, according to the modem stats (e.g. Mode B, 5 kHz, SDC=4, MSC=64, One 8.28kbps AAC service).

    The bottom half of the 10 kHz wide signal seems to consist of unmodulated carriers, always present on their published frequencies, and it may be there due to a misconfiguration on their part. I get more reliable/quicker lock if I tune up by 2.5 kHz.
  • Another new one I think at 17:43 UTC on 6025KHz

    IF Level: -9.1 dB
    SNR: 16.2 dB
    DRM mode B
    Chan 10kHz
    ILV L
    SDC 16 QAM
    MSC 64

    Medium range use, multipath resistant

    Services:

    1. AAC (1001) SNR Tiganesti E1 EEP Audio 20.96 kbps

    Diffusion exprimentale DRM par TDF depuis Issoudun
  • funklust seems unlikely.... there's a kiwisdr right at the campus there and it hears nil
  • Christoph provided this link for DRM info http://stuckis.com/DRM/
  • 1/16 0950Z WINB 7315 in WNY
  • Jan 16, UTC 17:00 good reception of Radio Romanie DRM transmission in French on 6025 kHz in Eindhoven, The Netherlands :
  • I see it is also possible to use DRM in 2 AM channels: Unfortunately the KiwiSDR doesn't allow the bandwidth to be expanded ?
  • jksjks
    edited January 16
    Yes, a Kiwi running in 4 or 8-channel mode has an audio bandwidth of 12 kHz (which is the IQ input bandwidth from DRMs perspective). So an 18 kHz mode DRM signal won't decode (at least not completely). However a 3-channel Kiwi has a 20 kHz bandwidth. I am trying to get DRM working in 3-channel mode. There are some issues still..
  • Experimenting with 2 instances of DRM on my 8073 KiwiSDR which uses a BeagleBoard AI. It works, but not as well as one instance, or so it seemed.



    Ron
    KA7U
  • jksjks
    edited January 16
    Yes, there's something wrong currently with multiple instances of DRM on the AI. I used to be able to run 4 of them and they used less than 100% of cpu1. But now even a single instance is over 50%. So something has changed. I haven't had time to look at AI issues recently. DRM or otherwise.
    rz3dvp
  • All India Radio 15030KHz heard in UK at 13:14

    IF Level: -10.9 dB
    SNR: 6.7 dB
    DRM mode B
    Chan 10kHz
    ILV L
    SDC 16
    MSC 64 QAM
    Protect: A=0 B=1
    Services: A=2 D=0
    Medium range use, multipath resistant

    Services:
    1 AAC (1) CHINESE EEP Audio 10.48 kbps
    2 AAC (2) VB / TIBETAN EEP Audio 10.48 kbps
    KA7USM2BYC
  • Listening to RNZI @11690KHz, 17:51 - 18:50 utc. This signal is great on an active dual loop antenna and the 210' top dipole. Makes an echo listening to both of them, but fun to play with the KiwiSDR's and the antennas. What a great extension @jks ! I'm looking forward to the future enhancements, especially for the BBAI.
    Ron
    KA7U

  • In case you haven't noticed, I am continuously updating the schedule based on your observations. So thank you for those. You don't even have to reload the page to get the latest schedule. Just close and reopen the extension (e.g. click IQ and then DRM again). Currently the schedule is loaded on every extension popup.

    There are a bunch of small changes in the works. I am trying to find the source of crashes in the AAC/xHE-AAC code during marginal signal conditions (most easily noticed with some of the CNR signals). This is bad because it causes the entire Kiwi server to reboot.
    KA7U
  • Yes, I have noticed the sked updates.... thanks
  • Hi
    I have heard the following AIR local stations on DRM -
    AIR Lucknow 756 khz @ 13.15 UTC
    AIR Panaji 1296 khz @ 13.30 UTC
    Best time to listen is just after sunset on the Delhi and Bangalore rx on sdr.hu
    The DRM official site carrying frequencies of AIR local stations is the best reference for DRM in India
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