Ham Radio . Magnum Experimentum
Antennas, experiments, engineering and other articles of interest to radio folks.
Yet another 40m Cloud Burner design featuring a folded dipole driven element plus one reflector wire to facilitate 40m NVIS contacts without need of a tall mast. The design uses electric fence posts for support and needs no balun.
Data from W4GO’s Virginia QSO Party operation confirms how well NVIS works from his SUV.
Near Vertical Incident Skywave (NVIS) propagation works wonders when the bands cooperate, but can slam the door shut at any moment.
Observations from the Virginia QSO Party confirm simulation results concerning horizontal antennas and NVIS propagation.
The Asymmetrical Hatted Vertical Dipole (AHVD) prototype is an easy to build, portable alternative to other freestanding vertical HF antennas such as the Buddipole.
Big HF loop antennas provide great performance, but they can’t do everything. 160 meter full wave loops won’t work well for NVIS when used at 3.8 MHz.
The EZNEC simulations of the 43 Foot Vertical and the BigIR Vertical HF antennas are summed up with some final thoughts on which to select if you can have only one.
Jim (K9YC) Brown’s toroid winding recipes provide a superb RF choke balun for 30-10m using RG316 and a #43 toroid.
In the name of science I cut the wire laying on the ground underneath my 40m fullwave horizontal loop to see what would happen.
QSO data from a state QSO party reveal trends in HF usage correlating with sunspot numbers.
Antennas shipping with ineffective antenna decoupling are on the rise as manufacturers daringly advocate 1/12 wave radials work.
The origins of two Virginia QSO Party awards: one for club, the other for single operator.
Tame the predictable mast currents found in any j-pole antenna grounding conductive mast using a simple stub. Shown is empirical evidence why this is a problem and a very simple solution all future grounded j-pole antennas should incorporate.
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.
One example of how amateur radio provides safety and service to the pubic providing otherwise impossible communications using the “Magic Band.”
A 1/4 wavelength of 75 ohm coax inline with a full wavelength of 50 ohm coax is all one needs to make a simple 80m dipole become a wideband dipole antenna.
My first journey to the mountains as SOTA activator was a success using minimalist VHF FM gear.
Basic tests of the LNR Precision EF-10/20/40 multi-band portable HF EFHW antenna including S11, SWR and a bandwidth check of the match box.
The background and details of the LNR (Par Electronics) EF-10/20/40 end fed half-wave multi-band portable HF antenna. Come see what’s inside the mysterious “black box.”
Real measured data reveal the UHF (PL259 and SO239) connectors have real limitations.
