From: Roman <rw3adb@YANDEX.ru>
To: rsgb_lf_group@blacksheep.org
In-Reply-To: <5B93B005.9030803@posteo.de>
References: <5B8FD14A.2080403@posteo.de> <14564361536176528@iva5-e9a4c5420a84.qloud-c.yandex.net> <5B904C48.9000302@posteo.de> <13745221536184440@sas1-0a6c2e2b59d7.qloud-c.yandex.net> <5B926595.4090705@posteo.de> <106526A3B629406BBA15C3AA514D9EA7@Clemens0811> <5B93B005.9030803@posteo.de>
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Date: Sun, 09 Sep 2018 07:03:42 +0300
Message-Id: <32320511536465822@iva1-16f33c6a446b.qloud-c.yandex.net>
Subject: Re: LF: RE: 137 kHz WSPR-2 on a 900m long ground loop, this weekend
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Congrats, Genosse Stefan!

Results are so optimisitc.
TNX for experiment!

73!
Roman


> Genossen!
> 
> I just matched the antenna and run some WSPR-2 transmissions on 137.425 kHz.
> 
> I'm getting 260 mA antenna current at 10 W RF power. So the overall loss
> resistance should be 150 Ohm (the wire has about 30 Ohm). For resonating
> i need about 2.5 nF in series to the wire.
> So the feed point impedance is Z = 150 Ohm + j450 Ohm, still behaving as
> a loop. Quite a comfortable managable impedance. I had to wind an output
> transformer on a "RIK20" core (Reichelt!), which works very well. The
> secondary number of turns was unknown at the beginning ;-)
> 
> Regular transmissions will start in an hour or so.
> 
> 73, Stefan
> 
> Am 08.09.2018 12:07, schrieb Clemens Paul:
> 
>> Hi Genosse Stefan,
>>
>>> Will someone catch the signal at all? At least i'm already
>>> asking for RX
>>> stations!
>>
>> I've just resonated my antenna aa inverted L on 137.5kHz (with 502µH)
>> and wil be ready to receive in WSPR-2 as soon as you start.
>>
>> 73
>> Clemens
>> DL4RAJ
>>
>>> -----Original Message-----
>>> From: owner-rsgb_lf_group@blacksheep.org
>>> [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC
>>> Sent: Friday, September 7, 2018 1:49 PM
>>> To: rsgb_lf_group@blacksheep.org
>>> Subject: LF: 137 kHz WSPR-2 on a 900m long ground loop, this weekend
>>>
>>> Genosse Roman, LF,
>>>
>>> Yesterday i built a small LF PA providing 10 W at 50 Ohm. It
>>> consumes 1
>>> A at 12 VDC. I intend to run an over-night WSPR-2 transmission (20% TX
>>> rate) on saturday night, using the ground loop or earth antenna in
>>> JN39WI. The signal generator is a Raspberry Pi running on a separate 7
>>> Ah lead gel accu. The PA has its own 7 Ah accu. The PA can switch from
>>> 2.5 W to 10 W :-)
>>>
>>> Will someone catch the signal at all? At least i'm already
>>> asking for RX
>>> stations!
>>>
>>> I'll carry some measuring equipment there, like my M0BMU LF tuning
>>> meter, some Cs, a T106-2 and some wire, also a small ferrite core to
>>> build a transformer if necessary.
>>> What could the feed point impedance be? I have no idea! My modified
>>> MFJ-259B covers LF but i expect it will be overloaded with strong
>>> signals on the antenna, so i try to match the antenna with the
>>> transmitter.
>>>
>>> More soon :-)
>>>
>>> 73, Stefan
>>>
>>> PS: Oh, i'm also going to connect two anti-parallel LEDs to
>>> the antenna
>>> to see if they shine. It is all a big game for old children!
>>>
>>> Am 05.09.2018 23:54, schrieb Roman:
>>>
>>>> OK Stefan.
>>>> Try it to do. may be wonderful results.
>>>>
>>>> Roman
>>>>
>>>>> Hello Roman,
>>>>>
>>>>> Yes maybe i'll build a quick PA tomorrow for LF and will
>>>
>>> transmit on LF
>>>
>>>>> for 24 hours, each 10 minutes, WSPR-2. I have no idea at
>>>
>>> all how this
>>>
>>>>> antenna performs on 137 kHz. Is it still a loop or rather a
>>>
>>> dipole or a
>>>
>>>>> mixture? At least it has about the length of a full size
>>>
>>> dipole for 137
>>>
>>>>> kHz. I would TX at 10 W RF power only, so that a small accu
>>>
>>> covers some
>>>
>>>>> hours. But i'm not yet sure if i can find the time to do it
>>>
>>> tomorrow.
>>>
>>>>> 73, Stefan
>>>>>
>>>>> PS: If the antenna acts as a dipole, then it is beaming to
>>>
>>> Russia directly.
>>>
>>>>> Am 05.09.2018 21:42, schrieb Roman:
>>>>>
>>>>>> Congrts, Stefan!
>>>>>>
>>>>>> We are follow by your success!
>>>>>> Listen, do you planning to operate 136 kHz, I hear, tell
>>>
>>> me pse - do you planing try to TX with that ant on 477 kHz and 160M?
>>>
>>>>>> I will be interestin to hear about results.
>>>>>>
>>>>>> 73!
>>>>>> Roman
>>>
>>> ---
>>> Diese E-Mail wurde von AVG auf Viren geprüft.
>>> http://www.avg.com
-- 
73!
Roman, RW3ADB