Tarheel 100A-HP Screwdriver Antenna (Photoblog), posted 28 Mar 2018. Mounting and measurements of a shortened electrical 1/4-wave vertical monopole antenna with a remotely controlled continuously adjustable center loading inductor.
Telonic TS-200A Coaxial Switch (Photoblog), posted 27 Oct 2016. A single pole six position rotary switch with BNC connectors with VSWR <1.1:1, insertion loss < 0.1 dB, and port isolation >70 dB through 1 GHz.
Smart Meter Interference to 902-928 MHz (Video), posted 18 Aug 2016. The uncontrolled proliferation of Smart Meters by utility companies causes increasing illegal interference to licensed users of the ITU Region 2 902-928 MHz amateur radio band.
"10 Watt 50 ohm QRP
Dummy Load with 40 dB Attenuator", Posted 28 Mar
2015. Ten watt 50 ohm dummy load (SWR 1.03:1 or better up
to 200 MHz) with 40 dB Attenuator in an Altoids box for
frequency and power measurements.
"144 MHz Omnidirectional Horizontal
Antennas", Posted 05 Jan 2013. NEC Model Comparisons
of Stacked Halo, Turnstile and Eggbeater Omnidirectional
Horizontally Polarized Antennas for 144 MHz
"WSPR Spot Report Analysis Spreadsheet",
Posted 21 August 2012. User-defined Chart and Statistical Analysis of Online WSPR Spot Database (Requires Microsoft Excel 2000 or later)
"Modeling Commercial Amateur Radio
Antennas", Posted August 2011. Evaluating the Arrow
OSJ146/440 J-Pole, Cushcraft R7 Vertical, Diamond D130J (Icom
AH7000) Discone, High Sierra Sidekick Screwdriver and Hamstick
Dipole Performance Through NEC Modeling
"Zip Cord Transmission Lines and Baluns",
Posted August 2011. An Analysis of a Low Cost Speaker Wire
with Common Mode Chokes as a High Frequency Transmission Line
"Measuring the MFJ-949B Antenna Tuner",
Posted 18 February 2011. Determining the Capacitance and
Inductance Ranges of this T-Network Antenna Tuning Unit
"Comparative Antenna Analysis with WSPR",
presented 1 March 2011 at River City Amateur Radio
Communications Society. Using the Weak Signal Propagation
Reporter Network to Compare Antenna Performance.
"Chebyshev/Butterworth Filter Design",
Posted 10 July 1998. An IBM BASIC program to design Chebyshev
and Butterworth low-pass, high-pass, band-pass and band-stop
filters.
"Butterworth Filter Design", QZX,
Vol 2:4, March 1984, pp. 3-5. A Sinclair BASIC program to design
Butterworth low-pass, high-pass, band-pass and band-stop
filters.
"Phased Vertical Antenna Patterns",
QZX, Vol 2:3, February 1984, p. 2. A Sinclair BASIC
program to print radiation pattern plots for phased vertical
antenna arrays.