bestBentWire
New Member
Hello,
I've been experimenting with Franklin co-linear antennas made up from 14 gauge single strand
copper ( from scraps of stripped 14-2 electrical wire ). I'm getting a range of just over
100 mile radius with the antenna strapped to a broom handle about 6 feet off the ground,
using the RTL-SDR usb module and dump1090 driver.
The dimensions for my best effort are: 137mm verticals, 67mm stub lengths spaced at 10mm
with both 75 ohm co-ax feed and 110mm co-ax half wave balun connected on the central stub
20mm away from the vertical sections.
I've been using xnec2c modeling software and I've noticed many of the dimensions can
have a critical effect on gain and VSWR so it's necessary to make many nec runs,
editing the input file to change various dimensions each time. I wrote a simple python script
that automatically creates the NEC input text files, making a simple job of repeatedly making up
antenna files with different trial dimensions.
Here's the python script in case anyone else can use it:
( You will need to change the filetype back from .txt to .py after downloading)
I've been experimenting with Franklin co-linear antennas made up from 14 gauge single strand
copper ( from scraps of stripped 14-2 electrical wire ). I'm getting a range of just over
100 mile radius with the antenna strapped to a broom handle about 6 feet off the ground,
using the RTL-SDR usb module and dump1090 driver.
The dimensions for my best effort are: 137mm verticals, 67mm stub lengths spaced at 10mm
with both 75 ohm co-ax feed and 110mm co-ax half wave balun connected on the central stub
20mm away from the vertical sections.
I've been using xnec2c modeling software and I've noticed many of the dimensions can
have a critical effect on gain and VSWR so it's necessary to make many nec runs,
editing the input file to change various dimensions each time. I wrote a simple python script
that automatically creates the NEC input text files, making a simple job of repeatedly making up
antenna files with different trial dimensions.
Here's the python script in case anyone else can use it:
( You will need to change the filetype back from .txt to .py after downloading)