Field strength survey of an M40-1 short helical vertical on 40m

This article documents a field strength survey of an M40-1 short helical vertical on 40m. This test is more a feasibility study of the experimental method and apparatus than an absolute measure of the antenna. The antenna under test is described at AUT – MobileOne M40-1 40m helical. Field strength was measured using a small … Continue reading Field strength survey of an M40-1 short helical vertical on 40m

Belrose field strength measurements of his 80m mobile whip

(Belrose 1998) described a mobile antenna system which, to his credit, the author validated its performance by making a series of field strength measurements and calculating radiation efficiency. It appears that Belrose has assumed the antenna is omni directional for ground wave, though he shows that for higher angle space wave it is not omni … Continue reading Belrose field strength measurements of his 80m mobile whip

Transmit performance of 2m hand held transceivers – absolute gain estimates

Transmit performance of 2m hand held transceivers reported relative field strength measurements for some transceiver / antenna combinations. This article documents a more careful measurement of the absolute field strength of one combination, and application of that knowledge to the other results. Measurements of field strength were done with Lou Destefano’s (VK3AQZ) VK3AQZ RF power meter … Continue reading Transmit performance of 2m hand held transceivers – absolute gain estimates

Transmit performance of 2m hand held transceivers

This article documents measurements of transmit performance of three hand held 2m radio with several antennas. Measurements of field strength were done with Lou Destefano’s (VK3AQZ) VK3AQZ RF power meter (RFPM1) and a small loop antenna. Above, the field strength meter, a RFPM1 with small loop antenna oriented for max gain in the direction of the … Continue reading Transmit performance of 2m hand held transceivers

Near-field field strength measurements using a diode detector

My recent article Near-field field strength measurements using the RFPM1 described a technique using VK3AQZ’s RF Power Meter which is based on the AD8307 log detector. There are many ways to measure low level RF power or voltage, and this article describes methods that I have used using a simple diode detector attached to the … Continue reading Near-field field strength measurements using a diode detector