Hi Luis,
Lol. Yes, maybe an antenna analyzer helps to understand things.
For the coil i would use isolated mains electric wire. We have 1.5mm^2
and 2.5mm^2 here in DL. Also there is 0.75mm^2 for some installations.
0.75 or 1.5 is a good choice for you i would say. I think you can get a
Q of 250 or so, which is fine. But sooner or later you will need a
bigger PA, HI :-)
73, Stefan
Am 19.10.2015 17:24, schrieb VIGILANT Luis Fernández:
Hi Fausto, Stefan, MF
That's what I need. Discussion
and brain storming ! :-)
Yes. The coil has too many
wounds and should be about 3.9mH
It is the first time I ty to
make such a thing so I used all the wire I had to see what I can get. I
can redo it and it is part
of the game. No problem
The internal variometer is what
everybody uses in such a big coils. So, has sense to go that way
>>have you an idea about the Q of this
coil?
Hi Luis,
Nice looking coil. It has a good ratio between diameter and length
although it would have been better to have a small gap between the wire
turns. And i didn't expect that you need so much L. What is the L of
this coil? Looks like 3 mH or so. You will need about 2 mH. But i can't
se the actual number of turns. Probably it is just right :-)
I would build my own variometer, i.e. drill 2 holes into the tube, add
an axis and put another coil on this axis.
https://dl.dropboxusercontent.com/u/19882028/MF/20141027_203720.jpg
Like this image. Ehm, what you can see there will not happen to you i
think. But anyway, be careful with high voltage!
Good luck!
73, Stefan
Am 19.10.2015 12:52, schrieb VIGILANT Luis Fernández:
Hi Stefan
This is a picture of the coil
25cm diameter pipe, 90 cm high
I can also fit this variometer
on the top side of the pipe
The -3dB of my signals yesterday
are probably due to QRN on the Rx. We had a big storm down in south EA
Another one is predicted for
tomorrow just here and strong rain. No good for installing the coil
Hi Luis,
Am 18.10.2015 21:59, schrieb VIGILANT Luis Fernández:
For the transformer I plan to recycle the one
osed for the loop. It has two big toroids 80mm external diameter
and 8mm thick. Both joined make
16mm thick. Unfortunately don't know which is the material used
Hm, sounds not optimal, somehow :-) But just start with a 1:1
transformer and a 50 Ohm dummy load as a first test. If the transformer
stays cold and the load (e.g. power consumption, or current meter
reading of the power supply) is the same with or without the
transformer, everything is fine.
Can be primary and secondary be
wounded one on top of the other ??
Yes, this is recommended!
Tonight reports on my remote
monitor are 3dB down. I made a modification
I have finally connected a wire
from top terrace to the fire extinguish pipe which runs inside the
building down
to the basements, were pumping
system is located. The wire is not yet connected to the ground side of
the vertical
BUT the actual radial
counterpoise runs parallel to this wire for about 5m
Seems like this can be the cause
of 3dB looses.
...but maybe the situation is different when matching the PA properly.
In the moment you don't know at all what the feed point impedance is.
...and how the PA behaves at that impedance connected.
RR. GL,
73, Stefan
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