[Fumes]

I'm using my old Futaba T7C heli radio at the moment and wanted to use the TH as arming swithch for the board.
It has the standard Throttle Hold switch, which lowers the throttle channel (ch 3) to a very low output and holds it there regardless of throttle stick input.

Now, if I assign Accessory0 to Chan 3 and lower the Neutral to a proper setting I can arm and dissarm the board with it using Accessory0 as trigger.

The problem is that I don't get proper Thottle output anymore. It has very limited range and behaves rather odd.
I'm I doing something fundamentaly wrong or is this "by design" in any way?

I'm using OneShot125 as output to ESCs if that has any relevance.
Of course, I could just bind another channel to that switch (ch 7 for example) and I would get the proper function but then again I wouldn't solve this problem and it itches. 

[TheOtherCliff]

It might be possible.

If you can set the TH switch so that it makes the throttle channel significantly lower than the lowest the stick can make it, then use the throttle channel for accessory with neutral set very low, half way between TH and min throttle stick.

Then you would use your collective channel (also connected to throttle stick) for thrust input to the FC.

[Fumes]

But it wouldn't be possible to use throttle channel as throttle input? I want to free up channel6 (collective/pitch) to use as EasytTune.

[TheOtherCliff]

I guess you are saying to use the one throttle channel for two functions.  That may be possible too.  You would just have to try it.

The key would be to have the TH output a min that is significantly less than the lowest the throttle stick can go and setting TH neutral half way between throttle min and TH min.

Set transmitter to output a normal range for throttle
Set transmitter to output TH that is lower than lowest throttle
Set the FC throttle min very low so you can see how low the throttle signal goes when you pull the stick back and firmly hold it against the stop
Set the throttle min to what you read when pulling the stick back
Set the throttle neutral a little above min so that you actually have to move the stick to get to neutral
Set the Accessory0 (or whatever number) to be used as TH to a very low min so you can see how low the TH switch goes
Flip the TH switch and note the value
Set the TH min to the value you noted
Set the TH neutral to be half way between throttle min and TH min

If this doesn't work for some reason, you may have to (on the transmitter) set the TH to a normal low and the min throttle stick to a higher value than that.