|Subject:||Re: VLF: Ground loop improvements and test carrier...|
|From:||Markus Vester <[email protected]>|
|Date:||Fri, 5 Apr 2019 14:36:44 +0000 (UTC)|
|Dkim-signature:||v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1554475008; bh=iFQ3Ws8mLbs2PE3SjG7bc2MbCpa8dkwb4lt3ihd042k=; h=Date:From:To:Subject:References:From:Subject; b=twmWbVkBlUVwLXfnCjqgmBl5PQaPZPHR2RzHOKaHx2jsALfqq9W7nHFTr2RE7AR3SUKQTu9Q6hzEKZbAaH+OaG7D5lv25Vhv/CbXVydY5RITUcPpzyvMxoAJY27gyL9JL5i/X2L8PfzAw5gCFGw+b2BVzQY0JABNvik3bdQrlGPFUQooHhZEqMJgAWSBnpLH7/iXkhqksYLRNrZ2Uu0w6oVFN267xQG7Up2uKf9xLOI3Yjih+a7ytVsMrgWfSIe8yjSdbKTQbiVcPUqmt092XsM7SfHjS9YJiNTj9coQLRpDf6r/NR03BJj+3RmKyi1Z8iWfTuKSML8bV+bLkDjasw==|
At DL0AO, we produced spectrograms and plots during the 5.17 kHz test last weekend. During the first session with the shorter guiderail antenna, signficant fading and a dip occured, most pronounced on the H-field receive antenna. Another deep dip happened immediately after Stefan switched to the long antenna, however that period may perhaps have been affected by a short retuning interruption at 12:58. Considering around 17 dB SNR in 1.5 x 3.8 mHz, the 6 dB variations seems to be too large to be explained by random noise alone. Thus we have been speculating about ionospheric variations or scintillations on a ten-minute timescale. Note that no solar x-ray or SID event had happened at the time.
Therefore I asked Stefan to repeat the test, which he did today, this time starting on the long antenna (10:39 - 11:15) and then going to the short one (11:19 - 12:10). This time the SNR was even better, and only small variations occured, perfectly within the range of noise statistics.
Von: DK7FC <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Mi, 3. Apr. 2019 20:26
Betreff: Re: VLF: Ground loop improvements and test carrier...
PS: Earlier that day, the same test was done at 5170.1 Hz. But there, the antenna current was different:
900m: T2019-03-31_12:31,+19m at I = 2.74 A
1130m: T2019-03-31_12:57,+31m at I = 2.12 A
|<Prev in Thread]||Current Thread||[Next in Thread>|
|Previous by Date:||Re: LF: Re: What's all thos then?, Markus Vester|
|Next by Date:||Re: VLF: Ground loop improvements and test carrier..., DK7FC|
|Previous by Thread:||Re: VLF: Ground loop improvements and test carrier..., DK7FC|
|Next by Thread:||Re: VLF: Ground loop improvements and test carrier..., DK7FC|
|Indexes:||[Date] [Thread] [Top] [All Lists]|