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Dear Dick and All,
yes, we will measure the antenna current
and tell after the test and we will be glad to receive the report from your
W&G.
About the mast: It is half of a halfwave-dipole - or let`s say
a folded groundplane. One of the two vertikal branches of this
groundplane is the mast, about 3 by 3m. It is connected to ground - 120 radials,
each 360m long (perfect ground?). As the groundplane is too short for 153KHz the
mast has a topload consisting of 3 ropes. Length is unknown (maybe 100m??), we
will estimate that when being there. The other branch of the folded groundplane
consists of 3 ropes, connected to the mast in a height of about 300m, at first
leading off the mast and then down and back and meeting in the
matching building. It looks a little confusing. We will have the mast
without any matching network, so have to take along our own
equipment.
73 Walter
-----Ursprüngliche Nachricht-----
Gesendet: Donnerstag, 18. Juli 2002
11:17
Betreff: Re: LF: Activity from DLF´s
360m mast
Dear Walter and the LF-gang,
Assuming
the 360m mast has no top load my antenna simulation program gives a feedpoint
impedance of
Z = 11.9 - j149 ohm over perfect ground. The reactive part
depends on the diameter of the mast of course which I have arbitrarily
put at 3m.
Be sure to measure the current into the mast so the EMRP
can be calculated.
I will probably not be at home to work you as we
will spent the day with several amateur radio friends at a camping site near
Eindhoven. But I will take my W & G SPM-12 with me, together with a frame
aerial so I hope I can measure your field strength.
Looking forward to
an interesting experiment I wish you and your friends good luck and a good
match.
73, Dick, PA0SE
At 22:24 15-7-02 +0200, you
wrote:
Hello to all LF`ers,
on Wednesday, 24th of July, the
153KHz transmitter of Deutschlandfunk in Donebach (JN49ON, 50Km SSE of
Frankfurt) will be off air due to scheduled maintenance. By the friendly
cooperation of the site personnel and with consent of the regulation
authorities, a small group of German LF amateurs has been granted access to
one of the 360m masts between 7:00 and 15:00UTC. With a little luck we might
be able to achieve about 30dB more radiation efficiency than at
home.
We
will probably need some time to work out the impedance matching. After that,
we intend to operate preferably in CW and Slow-CW modes. As we expect a
rather high noisefloor from the Frankfurt area, we will bring along a tuned
loop for receiving, and we will be QRV on 7030KHz in CW as well. If nothing
else works, please give us a phone call on+49 174 3692499, or send an email
note via the reflector or to [email protected] or [email protected].
Let`s look forward
to a successfull day, hopefully without thunderstorms or strong
noise.
73
The group: Markus - DF6NM, Walter - DJ2LF,
Ralph - DL2NDO, Ralph - DK3GH, Roland - DL3NDR, Franz - DL5NER
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