Re: Re: VLF: DJ8WX

[uwe-jannsen@kabelmail.de]

Hi all,

Stefan, the DC R of the coils in toto is 107,5 Ohm and the L is 284mH.

 

Your idea to arrange the coils in a pile made me brooding for a while.

 

solution: nearby the shed is located a stand (raised hide) abt 4,5m high.

 

Ill modify it, means to “gut” it, means removing the floor

and install a rack to fasten the coils

and find some materials to coat the lower part of the tower

and

and

 

so Ill be busy outdoors and the stn wont be on the air coming weeks.

 

The last transmission stopped at 1028UTC today.

 

GL

Uwe/dj8wx

 

 

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 06.05.2011 10:16
An: rsgb_lf_group@blacksheep.org
Betreff: Re: VLF: DJ8WX

---

Uwe,

QRO, big antenna and a low loss coil!
Uwe, i somewhere saw a photo of your loading coil. It consists of 3 coils that are separately placed, so not magnetically coupled. You may improve things if you couple them (i.e. put one above the other), This results in a higher L (yes yes, some losses come up as well) and so you maybe can take out one of them and reduce the losses in that way.
This may be the easiest way to increase efficiency but it does not solve your high voltage problem ;-) To reduce the voltages you need more wire in more height and then, less L.

BTW, do you know the DC resistance of your overall loading coil?

73, Stefan

Am 06.05.2011 09:57, schrieb mal hamilton:

Uwe

Go for BOTH  ie QRO es Big Antenna = Arm chair copy for the RX operator.

 

mal/g3kev

 

----- Original Message -----

From: uwe-jannsen@kabelmail.de

To: rsgb_lf_group@blacksheep.org

Sent: Thursday, May 05, 2011 9:07 PM

Subject: Re: Re: VLF: DJ8WX

Hi Mal,

instead of QRO I would prefer a more effectiv antenna.
I feel the day will come.

GL
Uwe/dj8wx

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 05.05.2011 18:35
An: rsgb_lf_group@blacksheep.org
Betreff: Re: VLF: DJ8WX

---

Uwe

I can see u mean business with plenty of QRO, this should be the aim for all LF operators to avoid eye strain and ear ache at the RX end

de g3kev

 

 

----- Original Message -----

From: uwe-jannsen@kabelmail.de

To: rsgb_lf_group@blacksheep.org

Sent: Thursday, May 05, 2011 6:18 PM

Subject: Re: VLF: DJ8WX

Hi Stefan,

 

The stn was on the air from yesterday 1442UTC until today 0856UTC

and sporadic ZOA in mode QRS30.

I didnt measure the PA output and I didnt measure the aerial current.
matching coils and PA  are located in a shed at abt 90m from the shack.
the shed is  shut. the key is somewhere hidden.

but Im doing something else: Im trying to meassure the FS using calibrated aerial and RX (ESH3).
but until now the noise makes the results problematic.
so I have to increase the output pwr step by step (day by day).
old days max pwr is not reached today. I estimate todays output pwr of 450W.

the max would be 750W.

750W is the  limit because otherwise (751W)  my XYL would  agn shriek when touching her metal garden tools.

 

Oh horror: neighbors boy climbed our fence and asked my wife if the fence wire is electric. No, she said, it isnt.

Secretly I connected a phasing tester to the fence wire: yes, it was (electric).

 

GL

Uwe/dj8wx/jo43sv

 

 

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 05.05.2011 12:52
An: rsgb_lf_group@blacksheep.org
Betreff: VLF: DJ8WX

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VLF,

Today DJ8WX is as strong as before (March 2011). About 20 dB SNR in 47
uHz and traces in the 600-window.

Uwe, what is yout TX power and antenna current? What does your wife
think about that? :-)

73, Stefan/DK7FC