Message-ID: <5B93C483.9070706@posteo.de>
Date: Sat, 08 Sep 2018 14:45:55 +0200
From: DK7FC <selberdenken@posteo.de>
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To: rsgb_lf_group@blacksheep.org
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> <0EF5260A733244EA81696DDC9EA5D1E1@Clemens0811>
In-Reply-To: <0EF5260A733244EA81696DDC9EA5D1E1@Clemens0811>
Subject: Re: LF: RE: 137 kHz WSPR-2 on a 900m long ground loop, this weekend
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RR,

Now, since 12 UTC the TX is in its final position and runs each 10 
minutes. It will run for 24 hours or so.
So far the results are quite satisfying, for just 10 watts. With 100 W, 
we could have a CW QSO in the groundwave range. Did you expect that?

Let's see what the night brings. Also the radiation pattern will be 
interesting...

More reports from more stations are welcome :-)

73, Stefan


Am 08.09.2018 14:02, schrieb Clemens Paul:
> Hi Genosse Stefan,
>
>   2018-09-08 11:56   DK7FC   0.137425   -17   -1   JN39   1   DL4RAJ   JN68kj   449   103
>   2018-09-08 11:56   DK7FC   0.137425   -11   0   JN39   1   DL0AO   JN59vk   349   89
>   2018-09-08 11:08   DK7FC   0.137425   -10   0   JN39   1   DL0AO   JN59vk   349   89
>   2018-09-08 11:56   DK7FC   0.137425   -22   0   JN39   1   PI4THT   JO32kf   306   359
>   2018-09-08 11:08   DK7FC   0.137424   -22   0   JN39   1   PI4THT   JO32kf   306   359
>   2018-09-08 11:56   DK7FC   0.137429   -18   0   JN39   1   DC0DX/RF   JO31lk   218   0
>   2018-09-08 11:56   DK7FC   0.137425   -26   0   JN39   1   DC5AL-R   JO31lk   218   0
>
> 73
> Clemens
> DL4RAJ
>
>
>
>
>    
>> -----Original Message-----
>> From: owner-rsgb_lf_group@blacksheep.org
>> [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC
>> Sent: Saturday, September 8, 2018 1:18 PM
>> To: rsgb_lf_group@blacksheep.org
>> Subject: Re: LF: RE: 137 kHz WSPR-2 on a 900m long ground
>> loop, this weekend
>>
>> 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
>>>>
>>>>
>>>>          
>>>
>>>        
>>      
>
>