Cambridge 302 Sounds and Meanings?

On my last flight my Cambridge 302 made several different types of
sounds and I began to wonder what they all mean and what they were
trying to tell me.

Sink - This is pretty straight forward as a continuous tone which gets
lower pitched as the sink gets greater. Howerver every once in a while
it simply goes quiet. That is understandable as we spend a lot of time
in sink and want some silence every once in a while. The question is,
when/why does it grow quiet? Looking through the manual I found the
following,

"Speed-to-fly dead band width - If you are flying in cruise mode
within the Speed-to-Fly dead-band width, the audio will be silent
(except if you are climbing!). If you set dead band width to 20 knots,
you will not hear cruise tones if you are flying within plus or minus
ten knots of the correct speed-to-fly for the current lift or sink
rate."

Lift - This is a "beeping" tone which gets higher pitched as the lift
gets greater. However there are two rates of beeping, I'll call them
normal and agressive. The agressive tone is less often heard except on
my last flight when the lift was particularly good. Are the two tones
relative to the rate of change of the lift (integral) and not the
amount of lift? If so, can the trigger point between the two tone
types be changed? I don't see any details in the manual.

Thanks for any ideas.

- John

John,

Check your setting for the "low speed alarm" this may be what is
causing you to think that the lift is giving you two different types of
tones. When your airspeed drops below the "low speed value", the audio
changes. I foget exactly how, but I think it simply "drops out" on a
repetitive basis that could be mistaken for two types of tones. Maybe?
Anyway, crank the low speed alarm value up fairly high (say 60
knots) and then work back down. In theory if you pull up into a thermal
and then push over it would be nice to have the audio warn you if you've
done that a bit too aggresively and things get mushy (pre stall). Test
with care obviously :-).

Gary

ContestID67 wrote:
On my last flight my Cambridge 302 made several different types of
sounds and I began to wonder what they all mean and what they were
trying to tell me.

Sink - This is pretty straight forward as a continuous tone which gets
lower pitched as the sink gets greater. Howerver every once in a while
it simply goes quiet. That is understandable as we spend a lot of time
in sink and want some silence every once in a while. The question is,
when/why does it grow quiet? Looking through the manual I found the
following,

"Speed-to-fly dead band width - If you are flying in cruise mode
within the Speed-to-Fly dead-band width, the audio will be silent
(except if you are climbing!). If you set dead band width to 20 knots,
you will not hear cruise tones if you are flying within plus or minus
ten knots of the correct speed-to-fly for the current lift or sink
rate."

Lift - This is a "beeping" tone which gets higher pitched as the lift
gets greater. However there are two rates of beeping, I'll call them
normal and agressive. The agressive tone is less often heard except on
my last flight when the lift was particularly good. Are the two tones
relative to the rate of change of the lift (integral) and not the
amount of lift? If so, can the trigger point between the two tone
types be changed? I don't see any details in the manual.

Thanks for any ideas.

- John

I looked over the manual twice and didn't see a "low speed alarm" in
the Cambridge 302. If there is one, that could be the answer to my
question. Maybe I should ask Cambridge themselves.

ContestID67 wrote:
I looked over the manual twice and didn't see a "low speed alarm" in
the Cambridge 302. If there is one, that could be the answer to my
question. Maybe I should ask Cambridge themselves.

Section 3.2 "The LCD Screens" - screen #8 on page 10. I have mine set
for 40 kts. Works great.

Tony V. LS6-b "6N"

ContestID67 wrote:
I looked over the manual twice and didn't see a "low speed alarm" in
the Cambridge 302. If there is one, that could be the answer to my
question. Maybe I should ask Cambridge themselves.
Check page 10 of the 302 manual. Screen 8 of the 302 sets the slow
speed alarm. Since the speed is also dependant on the g load, in
strong lift when the bank angle is increased, the slow speed threshold
will also increase.
Bob

ContestID67 wrote:
I looked over the manual twice and didn't see a "low speed alarm" in
the Cambridge 302. If there is one, that could be the answer to my
question. Maybe I should ask Cambridge themselves.



OK, looked it up. Slow Alarm Threshold - page #8 in the 302 as you push
the button to flip through the various pages. It will say "SLO". Make
sure this is set higher than your thermal airspeed and it also takes
into account G loading. Manual suggests 10% above the thermaling
airspeed, but start higher than that, and tinker with it until it only
shows up when you would agree that you've gotten the glider slower than
you'd like to get it. No substitute for proper airspeed managment, but
not bad to have a reminder. Hopefully this fixes the two tone climb you
mention.

ContestID67 wrote:

I looked over the manual twice and didn't see a "low speed alarm" in
the Cambridge 302. If there is one, that could be the answer to my
question. Maybe I should ask Cambridge themselves.

Don't bother. Page 10. Para 3.2, Screen #8.

Enjoy!

GC

The manual actually says to set the threshold about 10% above STALL speed not thermalling speed. It is intended to be a stall warning. You want it well below your normal a/s operating range.