Second Menu page
• alt: As you probably know the pressure is never constant in the atmosphere. There are
standard theorecal values that the variometer take in to account, but in reality the pressure
at a certain altude can be different in different moments. Here you can adjust the value of
the altude. As usual: Jp to select, up or down buons to change the value and Jp again to
confirm.
• upT: Up Threshold (in meters per seconds or feet per seconds), this is the value for which you
want the Jb-L20 gives you a posive audio feedback. It means it will beep for thermals. Some
people want posive feedback also for negave values: someone wants to have a thermal
beep also for example at -0.3. If you are going down at -0.3 mt/sec you are in a thermal
indeed, because even if you are going down the air is going up. It just happens that your
glider has a minimum sink rate lower than the thermal. However you can put the upT down
to -0.7. Obviously to avoid conflict in case the dwT is set to a higher value it will be automa-
cally adjusted at -0.1 lower than the upT. If the upT is set to values <= 0 it will be produced a
special audio feedback.
• dwT: Down Threshold (in meters per seconds or feet per seconds), this is the value for which
you want the Jb-L20 gives you a negave audio feedback. It means you are going down.
• vol: the volume can be set to 100% 50% or MUTE
• snd: you can choose between 2 different type of sounds. RELAX has a lower frequency. Jb
CLASSIC has higher frequency , like the Jb MINI (the previous model without display)
• res: RESPONSIVENESS , how fast you want the instrument reacts to thermals and how fast
you want V+ and V- are updated. Responsiveness can be NORMAL or FAST.
NORMAL: Will use a filter of 1 second for the first thermal beep feedback. Then the instrument
will give feedback and will be responsive every 0.5 seconds ll the end of the thermal. If the
Jb-L20 doesn’t detect another thermal within 1 second from the last thermal the 1 second
filter will be acvated again. This is done to cut out temporary “shaking”. This means also that
if you set Jb to +0.1 the first thermal will be detected aer 10 cm of variaon , but the beep
will be produced aer 20 cm... then aer 1 second it will become responsive at 10 cm of
difference, calculang variaon every half second. The values V+ and V- will be updated only
if a certain value is confirmed for at least 1 second. If you get a +6 for less than 1 second it will
not be recorded as V+ (max ascent, vercal speed value). Suitable for students.
FAST: No filter of 1 second, furthermore another algorithm is used to let Jb-L20 be more sensive.
The values V+ and V- are updated immediately. Suitable for pilots with over 100 hrs...
• unit: Altude can be set in meters or feet, and the variometer can be in mt/sec or /sec
