29-05-2025, 12:21 PM
(This post was last modified: 29-05-2025, 12:24 PM by David Stepney.)
Not very, then. My Magmo might as well be calibrated in kilofurlongs per fortnight for all the use it is. It's ok up to about 20mph (useful here in Wales) but thereafter becomes increasingly slow, reading 25 at 30, whilst an indicated 40 comes out at 48 mph (on GPS). I suspect the magnets are losing their magneticity, as the increase in inaccuracy appears to be on a logarithmic scale. Well the instrument is ninety year old!