Ham Radio . Magnum Experimentum
Antennas, experiments, engineering and other articles of interest to radio folks.
The Airspy YouLoop is a no tune, broadband, small footprint, affordable LF to HF receive antenna that works indoors. Its modular construction facilitates experiments to understand where the Möbius inspired electrical design provides benefit.
Measurements reveal the effects of common mode current on the J antenna.
Antenna patterns from a Diamond X50NA reveal how radials of proper size mitigate current running down the feedline and mounting structure.
Despite some antenna gain hype, the Diamond Antenna CP22E 2m base station antenna is a remarkable design achieving 5 dBi directivity in a slim low-profile design.
Using modest gear, station #6 of the Appalachian Trail Golden Packet exercise confirms 9600 bps works well for passing packets north and south.
With components from a variety of vendors, custom machining and a bit of trial and error, another variant of a small loop HF antenna is born.
Station #6 of the ATGP using modest gear and within a comfortable shelter.
Shown is a better configuration to fasten a choke to the Asymmetrical Hatted Vertical Dipole antenna.
2014 Appalachian Trail Golden Packet report from Hawksbill (aka Northern Virginia) Station #6
Shown is a minimal, but effective collection of gear for the APRS Golden Packet Appalachian Trail event.
I measured the SWR and Return Loss of a loaner Diamond X50 antenna.
Presented is a 3D E-Drawings rendering of the Asymmetrical Hatted Vertical Dipole antenna.
Jim (K9YC) Brown’s toroid winding recipes provide a superb RF choke balun for 30-10m using RG316 and a #43 toroid.
The Asymmetrical Hatted Vertical Dipole (AHVD) prototype is an easy to build, portable alternative to other freestanding vertical HF antennas such as the Buddipole.
We re-introduce the theory and origins of Cebik’s (W4RNL) Asymmetrical Hatted Vertical Dipole (AHVD) antenna with the hope to facilitate a vertical polarization portable 20-10m aerial for portable operations.
Build the venerable Hoverman TV antenna and watch digital broadcast high definition HDTV television this weekend. This version of a HDTV antenna uses amateur radio antenna building techniques to make a lightweight structure.
Some simple tweaks to a few text files try to make OpenWebRx more compatible with wider AM and FM RF bandwidths.
Try this microphone only technique to get you on the digital ham modes today.