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Ham Radio . Magnum Experimentum

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

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  • 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

HF

KX4O SDR Receiving Electronics

October 23, 2024January 8, 2023
SV1AFN J310 Preamp into Mini-Circuits Limiter

With a bit of work, one can successfully feed an array of LF-HF receivers from one broadband antenna.

Categories Electronics Tags 43 foot, DXE, HF, kiwisdr, LF, MF, Minicircuits, sdr, spotting, SV1AFN, WSPR

Wolf River Coils – Silver Bullet vs. Silver Bullet Platinum 1000

March 17, 2022March 16, 2022

We examine the differences between the original and higher power version of Wolf River Coils’ Silver Bullet 1000 tunable loading coils.

Categories Antennas Tags coil, HF, inductor, mobile, Wolf River, WRC

NVIS works very well… except when it doesn’t

May 24, 2018May 22, 2018
QSOs made into NoVa in the Virginia QSO Party

Near Vertical Incident Skywave (NVIS) propagation works wonders when the bands cooperate, but can slam the door shut at any moment.

Categories Propagation Tags 40m, 60m, 80m, HF, ionosphere, NVIS, solar

Sunspots and HF propagation

May 22, 2018January 26, 2018
VAQP QSO Percentages

QSO data from a state QSO party reveal trends in HF usage correlating with sunspot numbers.

Categories Operating Tips, Propagation Tags 40m, 80m, HF, NVIS, qsoparty, sunspots, VAQP, Virginia, Wallops

The need for 9600 bps AX.25

August 1, 2016
Where AX.25 fits into the ARS digital landscape

Despite its age AX.25 can compete with the slick newer digital technologies. Let’s see where packet fits into the digital landscape.

Categories Digital Modes Tags 802.11, ax.25, HF, MF, packet, packet radio, UHF, VAPN, VHF

Small Loop HF Antenna

July 4, 2021August 4, 2015

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.

Categories Antennas Tags 40m, Aluminum, CAD, copper, DXE, Elecraft, gear-motor, HF, LMD18201, mast, microcontoller, NVIS, octagon, PicAxe, PX3, small loop, Solidworks, speaker stand, STL, toroid, transformer, type 43

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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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