Skip to content

Ham Radio . Magnum Experimentum

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

  • Home
  • Radio Shorthand
    • Morse Abbreviations
    • Morse Code
    • Phonetic Alphabet
    • Q Signals
    • RST Signal Report
  • Tech Talk
    • Antenna Gain
    • Antenna Counterpoise
    • Digital
    • Logging Software
  • Amateur Radio, Why?
  • About
    • Privacy Policy
    • Terms and Conditions
    • Request Account
    • Contact
    • Sitemap
    • Advertise
  • Subjects
    • Activities
    • Antennas
    • contesting
    • Connectors
    • Digital Modes
    • EmComm
    • Installations
    • interfaces
    • Introspection
    • Lab Shootouts
    • Miscellaneous
    • mobile
    • NEC Shootouts
    • News
    • Operating Tips
    • power supply
    • Accessories
    • Promoting
    • Propagation
    • Public Service
    • Radios
    • Repair
    • Reviews
    • Safety
    • Software
    • station
    • Test Gear
    • Tomfoolery
    • Whackers
  • Home
  • Radio Shorthand
    • Morse Abbreviations
    • Morse Code
    • Phonetic Alphabet
    • Q Signals
    • RST Signal Report
  • Tech Talk
    • Antenna Gain
    • Antenna Counterpoise
    • Digital
    • Logging Software
  • Amateur Radio, Why?
  • About
    • Privacy Policy
    • Terms and Conditions
    • Request Account
    • Contact
    • Sitemap
    • Advertise
  • Subjects
    • Activities
    • Antennas
    • contesting
    • Connectors
    • Digital Modes
    • EmComm
    • Installations
    • interfaces
    • Introspection
    • Lab Shootouts
    • Miscellaneous
    • mobile
    • NEC Shootouts
    • News
    • Operating Tips
    • power supply
    • Accessories
    • Promoting
    • Propagation
    • Public Service
    • Radios
    • Repair
    • Reviews
    • Safety
    • Software
    • station
    • Test Gear
    • Tomfoolery
    • Whackers

Search Results for: LNR

EFHW LNR Precision EF-10/20/40MKII Test Data

May 18, 2019April 16, 2012
SWR Measurements of LNR Precision EF-10/20/40 End Fed Antenna

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.

Categories Antennas, Reviews Tags 10m, 20m, 40m, EFHW, end-fed, half wave, LNR Precision, measurement

EFHW LNR Precision EF-10/20/40MKII Examination

May 22, 2018April 15, 2012
Schematic of LNR Precision 10/20/40 Portable Antenna Matchbox

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.”

Categories Antennas, Reviews Tags 10m, 20m, 40m, EFHW, end-fed, half wave, LNR Precision, NEC, portable, QRP, Simulation

Electrically isolated end-fed vs. center-fed dipole radiation

January 1, 2021June 3, 2019
Measured magnetic field in vicinity of no-feedline end-fed and center-fed 10 MHz dipoles.

Testing confirms an end-fed dipole can energize the radiator nearly as well as a center-fed without need of additional counterpoise or other extraneous conductors.

Categories Antennas Tags center-fed, dipole, EFHW, end-fed, half wave, measurement, raspberry pi

Of end-feds and feed-lines

June 12, 2019March 3, 2019
Grounded EFHW feedline

Simulations suggest end-fed and center-fed half-wave dipoles share sensitivity to various feedline lengths, but in differing and manageable ways.

Categories Antennas Tags 4nec2, autotransformer, counterpoise, dipole, EFHW, end-fed, feedline, NEC, Simulation, transformer

EFHW transformer two ways

May 2, 2019February 12, 2019

I take a moment to document observed differences between end-fed antenna transformer topologies with and without ferrite core materials with a focus on the reactance compensation.

Categories Antennas Tags autotransformer, EFHW, end-fed, ferrite, transformer

Of fields and feedpoints

June 14, 2019December 31, 2016

Understanding how feed position along the half-wave dipole antenna affects the electric and magnetic fields around it.

Categories Antennas Tags AA5TB, Balanis, capacitance, dipole, E-field, EFHW, FDTD, Griffith, H-field, high impedance, Kirchhoff, link, link coupling, LNR, Simulation, Terman, voltage

KX4O/P VQP 2015 Expedition from MPX

April 28, 2015April 27, 2015
KX4O/P VQP MPX Portable Operation

Operating QRP portable from the back of a Subaru during activation of the rare VQP city of Manassas Park (MPX).

Categories Activities Tags Elecraft, Forster, KX3, Manassas Park, MPX, portable, PX3, QRP, Subaru, VAQP

SOTA HNY Activation

March 5, 2015January 2, 2014
View of gear

KX4O/p Summits on the Air (SOTA) activation of Hawksbill Mountain (W4V/SH-001) on New Year’s Eve on 40, 20 and 10 meters.

Categories Activities Tags 10m, 20m, 40m, KX3, kx4o, LNR Precision, SOTA

Asy Hat Vertical Dipole

April 8, 2020July 14, 2013
Three views showing a how a planed vertical need not always be the classic 1/4 wave monopole.

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.

Categories Antennas Tags 10m, 12m, 15m, 17m, 20m, AHVD, asymmetrical, Bravo, dipole, DX-Eng., kx4o, NEC, Simulation, vertical dipole, verticals

Help support this site

Become a Patron!
Antenna and repeater parts

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

Recently popular

  • Improving the Super-J
  • Airspy YouLoop LF/MF/HF Möbius Receive Antenna
  • Build this Vertical Portable HF Antenna
  • Slim Jim vs. Traditional J-pole Antenna
  • Small Loop HF Antenna
  • J-Pole Antenna – Should I ground it?
  • EFHW LNR Precision EF-10/20/40MKII Examination
  • Simulating the end-fed half-wave (EFHW) dipole antenna
  • The 43 foot vertical – The answer to ...
  • Mast Mountable J-Pole Antenna
© 2007-2023 John Scott Huggins and other authors and creators, All Rights Reserved.