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The KD1JV "Melt Solder" Digital QRP SWR/Power Meter operates across the 160m to 6m bands, featuring 9.9-watt and 990-milliwatt power scales, a peak hold mode for SSB, and a VSWR scale from 1:1 to 9.9:1. It utilizes a _Stockton directional coupler_ wound on a single binocular core and an _Atmel AVR ATtiny26L_ microcontroller for processing. The design incorporates _W7EL diode compensation_ in a non-inverting amplifier feedback loop to address diode voltage drop and non-linear behavior at low power levels, with software corrections applied for improved accuracy, particularly at QRP power levels up to 5 watts. Construction details include parts placement, transformer winding instructions for #26 magnet wire, and calibration procedures using a 1.5V alkaline battery or an oscilloscope with a 50-ohm dummy load. Packaging options are discussed for fitting the board into an Altoids tin or a deeper Whitman’s Sampler tin, with considerations for battery life extension by adding a third or fourth battery. Accuracy tests performed at 7 MHz compare readings against a True RMS power meter based on an _Analog Devices AD8361_ chip, showing typical deviations of 0-5% across various power levels.

A multiplatform software oscilloscope and logical analyzer software that acquires data using an arduino or a parallax USB Oscilloscope

The "REAL TIME ANTENNA GAIN COMPARATOR SYSTEM" by IK0BDO details a low-budget amateur radio tool designed for optimizing homebrew VHF/UHF antennas. It facilitates the simultaneous comparison of two antennas, one a known reference (e.g., a dipole) and the other under test, displaying their relative gain directly in decibels. The system addresses limitations of previous measurement benches by enabling on-field optimization, accounting for balun performance, impedance mismatching, and cable losses. The core of the device is an electronic solid-state switch utilizing PIN diodes, which alternates signal sampling from the two antennas 100 times per second. This rapid switching prevents the receiver's Automatic Gain Control (AGC) from compensating for signal differences, allowing for precise comparative measurements. The document includes detailed schematic diagrams for both the RF switching unit and the associated measure unit, which employs two VU-meters to display cyclic signal levels. It also provides guidance on setting up the PIN diode switching with an oscilloscope and adjusting trimmer potentiometers P1, P2, and P3 for optimal operation. Further sections cover the construction of VHF (144.150 KHz) and UHF (432.360 MHz) beacons for testing, along with critical considerations for selecting an appropriate test range or site. Recommendations include maintaining a minimum distance of 50 wavelengths between transmitting and receiving positions, avoiding ground reflections, and using reference antennas with gains similar to the antenna under examination. The author notes satisfactory results from measurements on dipoles and other antennas, highlighting the system's ability to appreciate fractional decibel differences.

The "Shortish Guide to Using an Oscilloscope" elucidates the fundamental operation of oscilloscopes, detailing the purpose and function of vertical, horizontal, and triggering controls. It explains how vertical gain in Volts/cm and horizontal scale in sec/cm enable measurement of signal amplitude and timing, respectively. The resource differentiates between analog and digital scopes, noting that digital scopes often feature "soft" controls and are inherently storage scopes capable of capturing non-repetitive events. The guide dedicates a significant section to the critical role of oscilloscope probes, emphasizing their design to transmit waveforms without distortion or added noise. It explains the concept of a 10x passive scope probe, which reduces circuit loading by a factor of ten and eliminates waveform distortion through probe compensation, typically adjusted using a 1kHz square wave reference output. The document also provides practical advice on probe care and compensation procedures. Further sections address grounding considerations, explaining how a scope measures voltage relative to its chassis ground, which is tied to the protective earth. It offers troubleshooting steps for a blank screen and outlines essential good practices, such as checking input gain and probe attenuation, while explicitly warning against misusing probes or connecting the ground clip to mains voltage.

The correct procedure for measuring SSB PEP (Peak Envelope Power), using an oscilloscope with a vertical bandwidth of at least 20 MHz, or a monitor scope.

Constructing a high-performance RF spectrum analyzer up to 1000 MHz requires careful attention to component selection, shielding, and circuit isolation. This resource details a project that improves upon the _Spectrum Analyzer for the Radio Amateur_ design by Wes Hayward (W7ZOI) and Terry White (K7TAU), incorporating ideas from Scotty Sprowls' project, particularly his 1013.3 MHz IF bandpass cavity filter. The analyzer utilizes a Mini-Circuits SRA-11 mixer with a sweeping local oscillator from 1013 to 2013 MHz, feeding into a 4-pole copper pipe cavity filter. The design employs a second SRA-11 mixer with a fixed 1024 MHz LO to produce a 10.7 MHz final IF. This signal then passes through narrowband resolution filters and is processed by Analog Devices AD603 and AD8307 ICs for IF amplification and logarithmic detection, driving an oscilloscope in X/Y mode. The project emphasizes modular construction, using salvaged components and double-sided FR4 material for PCBs, with critical notes on minimizing spurious images through effective shielding and proper voltage regulation for each module. Key components include a Z-Communications V585ME48 VCO for the first LO and a Z-Comm V583ME01 VCO controlled by a Motorola MC145151 PLL for the second LO. An optional Hittite HMC307 step attenuator and K&L 5L121-1000/T5000-O/O low-pass filter manage RF input. Tuning procedures for the 10.7 MHz IF resolution filter are also detailed, showing before-and-after spectrum views.

This project takes after the VGA-to-Scope converter by using composite video rather than VGA signals to create a display on an oscilloscope.

Using an oscilloscope to tune a Tesla coil for resonance includes video and instructions

Some information regarding the use of an Oscilloscope by SM0VPO

The basics of using an oscilloscope, this article is meant for thiose with very little or no experience at all with electronics or oscilloscope.

RF Power measurement using a DVM, RF Power measurement using an RF detector, RF Power measurement using an Oscilloscope and using a Spectrum Analyzer

A homebrew spectrum analyzer, the Specan, provides a crucial measurement capability often missing from the typical amateur radio shack, allowing for detailed analysis of RF signals up to 70 MHz. This double-conversion superheterodyne receiver design incorporates 112 MHz and 12 MHz intermediate frequencies, utilizing an _Si570_ as the local oscillator for fine tuning down to 1 Hz steps. It offers two resolution bandwidths: 300 KHz for broad spectrum sweeps and 1 KHz for precise close-in distortion measurements, achieving an 80 dB spur-free dynamic range at 1 KHz resolution. The project, a reboot of the classic _W7ZOI/K7TAU_ design from November 1998 QST, integrates an _Arduino_ microcontroller for controlling the Si570, managing a front-panel LCD, and communicating with a PC for spectrum plotting. This approach significantly reduces cost compared to commercial units, making advanced RF diagnostics accessible to homebrewers. The Specan can measure carrier suppression, VFO cleanliness, antenna VSWR, transmitter harmonics, and filter passband shapes, providing insights beyond what an oscilloscope or frequency counter can offer. Construction emphasizes modularity and careful shielding, with each stage built and tested individually on unetched copper clad board. The design includes detailed instructions for integrating the Arduino, building the Si570 oscillator, and aligning the various modules, often using the Specan itself for calibration. It requires a well-regulated linear power supply and can be built with common tools and readily available components, making it a practical and rewarding endeavor for those looking to enhance their RF test bench.