From: Roman <rw3adb@YANDEX.ru>
To: rsgb_lf_group@blacksheep.org
In-Reply-To: <5D134198.8070003@posteo.de>
References: <9ec649ed-7852-89b8-cb0e-d646de9538a9@rtv5.cz> <5D124169.1080309@posteo.de> <5D1268E1.9020500@posteo.de> <15144271561539491@myt5-cf6d29327892.qloud-c.yandex.net> <5D134198.8070003@posteo.de>
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Date: Thu, 27 Jun 2019 12:50:22 +0300
Message-Id: <6142931561629022@sas1-0a6c2e2b59d7.qloud-c.yandex.net>
Subject: Re: ULF/VLF: amateur stair case / carrier transmissions
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Gut Abend Genosse Funkamateur Stefan!

Do not understood exactly - whats model of drone? Quadrocopter?
20 min so little time, of course.
We are discuss about transmit power for copter by wires from the ground, not batteries.

73!
Roman

> Hello Genosse Funkamateur Roman,
> 
> I'm sorry, the 'drone' was just a typo. I simply meant 'done' instead.
> 
> 73,Stefan
> 
> Am 26.06.2019 10:58, schrieb Roman:
> 
>> Guten morgen Genosse Funkamateur Stefan!
>>
>> Congrats with your success!
>>
>> Let us to know more details about drone antenna?
>> We are discuss about that way in 2011 on 136.su forum.
>> Very interesting!
>>
>> 73!
>> Roman
>>
>>> Hi all,
>>>
>>> Today, some 20 minute long carrier transmissions were drone from JN39WI
>>> again. The main intention was to calibrate my local RDF spectrogram
>>> (still to be done) in the range below 16.4 kHz (JXN) and above 82 Hz
>>> (ZEVS). So that was a amateur radio ULF/VLF staircase somehow, despite
>>> the weak signal strength relative to commercial transmitters.
>>>
>>> It was a hot day! Far> 30 C here. I started early in the morning and
>>> enjoyed the fresh air in the forest.
>>>
>>> The DC resistance of the 1130m ground loop increased to 73.2 Ohm
>>> (measured at 1 A) due to the dry soil. It confirms the dependency shown
>>> in the last year! In 2018 i saw the resistance rising up to 94 Ohm in
>>> late October, then it dropped to 57 Ohm (-40 %) in just 2 months.
>>>
>>> It was interesting to see that the antenna current is much higher at
>>> lower frequencies (always at resonance | the PA output voltage is nearly
>>> constant). This effect was very clearly expressed.
>>>
>>> IF of interest for other stations (having a data storage):
>>>
>>> Frequency/Hz Start time/UTC Antenna current/A
>>> 970.005 2019-06-25_08:36:20,+20m 2.26
>>> 2970.005 2019-06-25_08:13:30,+20m 2.19
>>> 5170.005 2019-06-25_07:51:00,+20m 2.09
>>> 8270.005 2019-06-25_07:23:00,+25m 1.85
>>> end of the official part.
>>>
>>> BTW, since a few days, the VLF RX site at DL0AO has a 3 axis VLF
>>> receiver recording data from a Octo-soundcard and a Raspberry pi 3,
>>> saving data to a 4 TB HDD so there is one more station that won't miss
>>> anything from now on (for example unannounced transmissions by SAQ).
>>>
>>> Some spectrograms may be shown later.
>>>
>>> Evetually there was a problem with the sample rate correction due to the
>>> upheating car, which caused a high deviation of the tracked sample rate.
>>> The max allowed range of 10 ppm was left in the end of the experiment
>>> but this was noticed a bit late, maybe.
>>>
>>> 73, Stefan
-- 
73!
Roman, RW3ADB