RX antenna - K9AY loops switch with remotly VARIABLE Rload
This revision is from 2018/02/26 18:51. You can Restore it.
Current version 3.1 - Variable Rload with FIXed JUMPER
Quick Start Guide
- K9AY LOOPs design - more size variants
- Assembling KIT
- Schematic diagram
- Example of controller
Assembling KIT
The drill drawing
Paste the drawing on the box and fix it with some tape.
Capacitors
- solder 100nF YELLOW capacitors
Protection diodes
- solder 6 + 6 diodes
- these diodes protect Rload resistor against high power, electrostatic etc.
Insert PTC 100mA and rest parts
- PTC EX10
- rest parts
chooce the control way...
- By the jumper JP3 you can select 50 or 75 Ohm coax output
- Jumper JP1 must be short if you want to control direction over coax
- By the jumper JP2 you can select controlling over coax or DC voltage on connector X3
FIXed Rload !
- You can use this VARiable Rload KIT as FIXed one.
- Than you need only coax cable to control direction etc
- Conect JP4 to SHORT - and you have fixed Rload abt 460 Ohm / 4W
- DO NOT APPLY ANY VOLTAGE TO VTL!
TRANSFORMERS winding - very important thing!
- for 50 ohm coax feed line : 2 turns on primar (coax) and 6 turns on secondar side (loop)
- for 75 ohm coax feed line : 2 turns on primar (coax) and 5 turns on secondar side (loop)
- In version 2.3 and higher, you can select Coax impedance by jumper JP3.
- Transformer should have 5 + 1 turns.
Wind the coax
- Common mode current choke construction
- Wind 4 turns on one side than cross to another side of cores and wind rest turns.
Solder the coax
KIT - all parts assembled.
Example of controller
- Injector to coax line:
- direction and VAC Rload controller
K9AY loops design example.
- It is VERY recomended to place K9AY loop antenna as far as possible from metal towers, antennas and wires. This hepls to obtain better paramaters of antenna ( directivity and noise ).
- K9AY Loop design page
