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Ham Radio . Magnum Experimentum

Antennas, experiments, engineering and other articles of interest to radio folks.

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inductance

Antenna radiator decoupling stub flub?

February 18, 2019December 29, 2018
The pursuit of the single half-wave at 3rd harmonic.

Measurements and analysis suggest why quarter-wave stubs fail to completely isolate radiator conductors on multi-band antennas including the popular rollup 2m/440 J-Pole products. Possible improvements are shown.

Categories Antennas Tags 2m, 70cm, choke, coaxial choke, collinear, dual-band, inductance, J-Pole, NEC, portable, resistance, Simulation

Mast Mountable J-Pole Antenna

December 8, 2017June 17, 2015
Overview highlighting novel features of mast mountable j-pole antenna.

The J-Pole antenna’s long and storied design history is due for one more chapter to mitigate the longstanding mast current and reliability issues.

Categories Antennas Tags inductance, J-Pole, Simulation, stub, UHF, VHF

80 Meters for BigIR

February 26, 2014August 17, 2008

The BigIR antenna from Fluid Motion looks like a winner, but there are some concerns about the 80 meter option.

Categories Antennas Tags 10m, 15m, 20m, 30m, 40m, 60m, 80m, BigIR, inductance, relays, stepper, SteppIR, taps, toroid, verticals

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Topics & Keywords

2m 6m 10m 15m 20m 40m 43 foot 70cm 80m AHVD APRS Baluns battery BigIR copper Diamond dipole DX-Eng. EFHW Elecraft end-fed EZNEC Field Day Golden Packet hexbeam J-Pole Kenwood kj4faj KX3 kx4o measurement mobile NEC NMO NVIS packet PL259 QRP sdr Simulation SteppIR UHF vertical dipole verticals VHF
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