Return Loss sweep using IC7410, RL bridge, and RFPM1

This article demonstrates an automated Return Loss scan of an antenna using: IC-7410 transceiver with CIV; 40dB power attenuator; Return Loss Bridge (RLB); RFPM1 with USB data logger (A prototype data logger for RFPM1); and a PC orchestrating the test. Automation facilitates: measurement of a large number of data points; improved accuracy by reducing the … Continue reading Return Loss sweep using IC7410, RL bridge, and RFPM1

A prototype data logger for RFPM1

This project is a data logger accessory for Lou Destefano’s (VK3AQZ) RF Power Meter kit (RFPM1). The RFPM1 develops an analog signal 0-2000mV corresponding to 0-100dB input power range, -85-16dBm. The module described here produces a digital output scaled -85.0 to 15.0 for 0-2000mV input. The hardware is based on a clone of the Digispark ATTiny85 … Continue reading A prototype data logger for RFPM1

Near-field field strength measurements using the RFPM1

Review of Boswell et al paper “Performance of a small loop antenna in the 3-10 MHz band” discussed measurement of near-field field strength for measurement of performance of a small transmitting loop (STL). This article describes a method of performing near-field field strength measurements using a portable RF power meter (RFPM1) and a small untuned … Continue reading Near-field field strength measurements using the RFPM1

VK3AQZ RF power meter (RFPM1) – filter response example

This article shows use of Lou Destefano’s (VK3AQZ) VK3AQZ RF power meter (RFPM1) to plot the response of a 144MHz filter. Above, the RFPM1 as used. Above, the test setup. The filter (DUT) is connected between a standard signal generator (SSG), and the RFPM1 connected to the filter output. A DVM recorded the DC voltage on … Continue reading VK3AQZ RF power meter (RFPM1) – filter response example

Chinese AD8307 power measurement module #2

At Chinese AD8307 power measurement module #1 I documented the first phase of checkout of a low cost AD8307 module. There are two requirements for accurate power measurement: input impedance of the power meter must be very close to 50+j0Ω (say input VSWR<1.2); and then gain from the SMA terminals to the AD8307 input terminals … Continue reading Chinese AD8307 power measurement module #2