Borgelt B300 Club variometer system                       4th July 2012

A simple variometer for club two seat sailplanes and early solo single seaters.

Also for ultralights and powered aircraft for soaring assisted powered or unpowered flight.

Download B300 manual as PDF file: B300man.pdf


Same size, response and climb audio as B400 at a lower price.


B300 Club Variometer Designed to train students and new soaring pilots in use of audio from the start.

Climb optimiser - green LED lights when vario is above 20 second running average reading. Simple, one mode, “ up” audio.

plus optional


Digital averager displays for B300/B400          DAD -S  and DAD -L

B400 repeater 





The B300 is available in both 57mm and 80mm sizes for easy installation in existing instrument holes and is only 85mm deep behind the panel including connectors (20mm shorter than the B40).


One of two small full time digital averager displays may be driven by the  B300. The advantage of the separate display is that it may be mounted in or very close to the instrument panel  glareshield, close to the pilot’s line of sight. One display is 38 x 14mm with 6.3 mm high digits (DAD-S) , the other is 50 x 21 mm with 12.5mm high digits(DAD-L). The displays are supplied with 0.5 m cables with plugs which plug in to a matching socket on the rear of the B300.


The B300 uses surface mount technology in the electronics and the variometer display is by a small stepper motor driven pointer plus one high brightness LED. This provides the display with far better resolution and contrast than the LCD type pointers under all the changing lighting conditions typical in a circling sailplane. The display resolution is around 1/40 of a knot. This means a far smoother indication and much faster recognition of which way the pointer is moving particularly if the lift is weak. This is nearly 20 times the resolution of typical LCD pointers.


Audio “Up” only. A rising tone with the tone being chopped in lift. When the lift is above the running twenty second average the Green LED on the dial lights indicating that the climb is getting better.


Volume control is by a centre off toggle switch in the lower left mounting screw position.


The instrument is can be fitted with an external speaker with case and mount. This avoids problems with the speaker magnetic field causing compass errors as the speaker can be remotely mounted which also helps audibility.


Total energy compensation is by TE probe making for easy installation and setup. Excellent TE probes are available from Borgelt Instruments.