"Astrodynamics without the mathematics - how to fly spacecraft" -  John Cooke GM8OTI

Summary: "We send a lot of stuff into Earth orbit, and (more interesting) to other planets, moons and other objects in the solar system (and even beyond). As radio amateurs we know how to communicate with these probes - but how do we get them there, and how do we put them where we want them? This talk explains, without recourse to detailed mathematics - though lots of physics concepts are used, along with diagrams and demonstrations."

LRS Viral Net #89 - Wed 2 March 2022.

Present: Pete GM4BYF (c), Brian GM8BJF (Peebles), Peter GM4DTH, Mike GM8KCS, Melvyn GM4HYR, George GM4COK/DU1GM (Philippines), Briain GM8PKL.

Audio recording tnx Peter DTH: 


On 23rd February 2022 Brian Howie GM4DIJ gave "An Introduction to OpenEMS,

a Free Electro-Magnetic Simulator".  

Brian writes: "OpenEMS is a free and open electromagnetic field solver using the Finite Difference Time Domain method. It was created by Thortsten Liebig at the General & Theoretical Engineering University in Germany. FTDT is a time-domain approximation of Maxwell's equations to calculate the results. I have described antenna modelling using NEC2, mainly for wire antennas in previous talks. The big advantage of OpenEMS over NEC2 is that it can simulate complex structures, such as patch, horn antennas waveguides and bulk dielectric materials with different EM properties. I will demonstrate how to create simple models and show some of the work I've done and some of the tutorials supplied".

Click for Zoom video recording.

 LRS Viral Net #88 - Wed 16th Feb.

Participants: Colin GM4HWO (c), Brian GM8BJF, Pete GM4BYF, Mike GM8KCS, Peter GM4DTH, Briain GM8PKL, Melvyn GM4HYR.

Tnx Peter for recording: 


On Wed 9th Feb 2022 at the Braid Hills Hotel James Gentles GM4WZP gave a great talk on the History of the Pocket Calculator - 5000 years and counting.

Click for video recording by Colin GM4EAU (tnx) - may not be available forever - limited memory!


 LRS Viral Net #87 - Wed 2nd Feb.

Peter GM4DTH (c), Brian GM4DIJ, Brian GM8BJF. 

BJF in Peebles was using a remote Tx in Edinburgh (new FT-706/2G) - 5&9 !

Audio tnx Peter GM4DTH:



Malcolm talked on Zoom about using vertical dipole arrays (VDAs) from the shores of Loch Fyne. He had operated in the CQWW CW contest in November 2014 (LRS talk 11 Feb 2015) and again in 2021 along with Nick Henwood G3RWF (former RSGB President), with a different set of antennas. He shared his 2021 experiences and tried to draw some conclusions about the best aerials to use in practice.

Many thanks to Malcolm for his great talk and also to James GM4WZP and Colin GM4EAU for setting-up the Zoom facility which worked faultlessly, including asking questions afterwards.

Viral Net #86 - Wed 19th Jan 2022

Participants: Colin GM4HWO (c), John GM8OTI, Briain GM8PKL, Pete GM4BYF, Peter GM4DTH, Brian GM8BJF (Peebles), Melvyn GM4HYR, Mike GM8KCS, Brian GM4DIJ, Willie GM0CII.

Audio tnx Peter GM4DTH: