An A/B comparison on 40m over a 17,000km path using QRSS

This article reports an experiment to compare two nearby transmitting systems on 40m over a 17,000km path using QRSS, one of them using two different antenna systems.

The receiving station was G6AVK east of London UK.

The two transmitting stations are about 18km apart about 100km S/SW of Sydney (Australia):

Both stations were using 5W of RF output power, and A1 QRSS telegraphy using a Simple Morse beacon keyer with a quite standard transceiver in CW mode adjusted for 5W of output using an external power meter.

Grabber images


The following images were from the G6AVK grabber. These two images were from the peak in signal strength after the path had 'opened'.

VK1OD is on 7000.820kHz, and VK2DVK is on 7000.830kHz.

Fig 1:


Fig 2:

VK2DVK was using the OCF dipole until 19:45, the vertical until 19:55, and the OCF dipole after that. The antenna changes occurred about midway through each 10min grab.

Figs 1-2 show that whilst VK1OD's signal remained fairly consistent over the two grab periods, there is a noticeable increase in VK2DVK's signal using the OCF dipole compared to the vertical.

Results could be quite different in different directions and different path elevations, and possibly at different times, and indeed have been on a path to W4HBK in Pensacola.

Links / References


Version Date Description
1.01 08/10/2012 Initial.

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