End fed half wave antenna 40/30/20m
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For my SOTA activities, i recently bought a QRP transceiver QRP SW-3B, which is a three-band QRP CW only for 40/30/20 m.
So, i needed an antenna that would allow to use these 3 bands in SOTA portable activity.
Already having some experience with the EFHW antenna, i decided to build one for 40/30/20m.
The main advantages of this EFHW antenna are :
- easy to build
- multiband
- needs only one support, can be installed in line, inverted V, zigzag.
- fed at its extremity, can be directed connected to the transceriver, without any coaxial cable.
- the radiating part is at the center
All these advantages are welcome for portable operations and make this antenna a perfect candidate for SOTA
Cushcraft traps repairing.
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I used the Cushcraft A3 et A4s yagis and soon or later, problems are appearing..
Here are the results of my investigations and repairing technic, that can be applied to other models and trades as well.
What is described here applies to a A4s triband antenna, but the reasoning can be made for any multi-band yagi or vertical.
Universal K3NG rotor interface PCB
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- Hits: 21223
Description of a PCB, also called "shield" allowing to build a universal rotator interface based on the K3NG software. Only the AZIMUT function is supported.
This PCB has been thinked to be used either with a LCD display or an Ethernet shield to allow a remote usage via IP, and for a rotator using a variable resistor for the azimut value . (HAM IV or CD44 in my case)
The board includes :
- a 5V/1A regulator
- a header to plug an Arduino UNO and an Ethernet shield
- a HE10 male connector for to LCD display with a ribbon cable
- a 5 pin DIN connector (+ ground shell) to connect the rotator control box
- 2 connectors for the "Clockwise" and "Counterclockwise" pushbuttons
- a multi-turn ajustable resistor VR2 for the azimut calibration
- an ajustable resistor VR1 for the LCD contrast
- 3 transistors for the CW, CCW, and BRAKE commands (open collector outputs)
I still have some naked pcb boards left. If interested, please feel to contact me.
The GR20 - Planning & advices
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The GR20 is a mythical long distance hiking trail that crosses the island of Corsica diagonally, from Calenzana in the North, to Conca in the South.
The 200km trail follows the granite backbone of mountains that divides the island in two, many of which soar above 2000m altitude. The GR20 is the best and toughest long distance hike in Europe !
I made my first GR20 in 2011 and promised myself to make it again with my son for my 60th birthday. So in 2017, i planned it and here are few advices. We made it in 10 days.
If you find this anything of helpful, please leave a post..
K3NG rotator via Ethernet
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- Hits: 33861
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While building up my remote station, i was looking for a solution to control one or 2 azimuth only rotators via the Internet. There are several solutions and i finally adopted the K3NG rotator project i already used for a rotator controller connected via USB to my computer. |
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