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Old 03-06-2009, 11:25 AM   #76 (permalink)
Finless
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Join Date: Nov 2005
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Just an FYI about true gain from a JR or DX radio.

You have to do math to know TRUE gyro gain when using a DX or JR radio.
If using travel adjust it is X / 1.44 = true gain. So lets say you had 40 set for travel adjust. 40 / 1.44 = 28% gain (rounded).

Now the gyro menu works different! This is because anything above 50 is heading hold mode and anything below 50 is rate mode. So the math to figure out true gain is (X - 50) X 1.44 = true gain.
So lets say you had 72 in your gyro menu
72 - 50 = 22
22 X 1.44 = 31.68 or 32% rounded.

So you have to understand this to KNOW what gain your are really telling the gyro to use. When someone says I am running 20 you better ask the follow up questions. Gyro menu? Travel adjust? TRUE GAIN?

Don't believe me on this? Go to my forum and in the JR770 gyro videos I have a Gyro Gain 101 video where I go through this using a gyro (611 and Spartan) that has a display showing what IT sees as the gain value.

Now another lesson learned when I was doing those videos. The gyro menu has much less control resolution than using travel adjust!
Why you ask?
Because the gyro menu goes from 0 to 100 right? Anything above 50 is HH mode and below is rate mode right? OK that means there are only 50 steps of control available in HH mode and only 50 steps of control available in rate mode. If you watch my gain 101 video you will see for example when the gyro menu was set to 72 the gyro shows 32%. When the gyro menu was set to 71, the gyro displayed 30. I could not even set for 31% gain!

Now, using travel adjust with the gear switch up you get 0 - 100 or 100 steps of control for HH mode. With gear switch down you get 0 - 100 or 100 steps of control for rate mode. Thus you can set any gain and not be limited in control resolution!

Thus I have stopped using the gyro menu for 2 reasons.
1) The math is much easier to figure out true gain
2) You get much finer gain control!

Hope that helps,
Bob
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