Vario history

The LR3

It’s now more than twenty years since the last LR3 was sold, but LR3 ’s still change hands sometimes even for money and see occasional use in the air. I don’t support repairs any more but essential repair data, circuits and layouts are reproduced here.

Manufactured between 1989 and 1992, the LR3 was the last model of alti-vario from Lindsay Ruddock.

To see what the choice of varios was at the time, look at the 1990 vario review by Tim Williams in Skywings! magazine:

The LR2

The LR2 preceded the LR3. Altimeter and vario performance were similar but the LR2 circuit boards were packaged in a functional rectangular box. (The LR3 also added more functionality such as the averager)

More background to the LR2 can be had from a review in the US HGA magazine Hang Gliding:

Although I have never seen it, I understand there is an LR2 on display in the Southampton Hall of Aviation.

A link to another LR2 photo - Darren Arkwright flying Owens Valley, California at 14810’ in 1993 with an LR2 on the upright.

The LR1

Before the LR2, there were analog and digital versions of the LR1. This was a simple audio-visual vario similar to that described in my ETI article but built around an improved silicon pressure sensor from IC Sensors.

The article describes how to knock up a simple audio-visual vario and was aimed at the surprising number of pilots with the hobby skills to make their own vario. The article is still of interest anyone wanting to make their own vario.