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Re: LF: EA5DOM going vertical

To: [email protected]
Subject: Re: LF: EA5DOM going vertical
From: DK7FC <[email protected]>
Date: Mon, 19 Oct 2015 14:45:20 +0200
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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
 
73 de Luis
EA5DOM


De: [email protected] [mailto:[email protected]] En nombre de DK7FC
Enviado el: domingo, 18 de octubre de 2015 23:20
Para: [email protected]
Asunto: Re: LF: EA5DOM going vertical

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.
 Keep tuned !
RR. GL,

73, Stefan
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