Uwe,
OK, fast convincing ;-)
Good luck! The WX would be excellent here for such a work!
107 Ohm for 284 mH sound very good! I have 180 Ohm for 190 mH. But the
coil was dimensioned for 550 mH. If i would use the biggest possible
wire to get 190 mH on that water barrel (about 0.8 mm diameter
enamelled wire) i think i would achieve about 60 Ohm. This would almost
be worth the effort but usually i want to serve different bands where i
need more L. And my car is to small for 2 of these coils, even when
stacked ;-)
73, Stefan
Am 06.05.2011 21:54, schrieb [email protected]:
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
Von: [email protected]
Gesendet: 06.05.2011 10:16
An: [email protected]
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 -----
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
Von: [email protected]
Gesendet: 05.05.2011 18:35
An: [email protected]
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 -----
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
Von: [email protected]
Gesendet: 05.05.2011 12:52
An: [email protected]
Betreff: VLF: DJ8WX
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
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