Idle-Up Mixer for the JR PCM 10SX, SXII and 10X  

Idle-Up is a very useful function for larger aircraft because it allows you to set up a very slow idle to produce a breaking effect for landing and at the flip of a switch provide a higher idle that is very dependable for flying.  It is especially useful in the thinner air of higher altitudes.

Our Idle-Up function will use the AUX5 knob/channel to set how much the engine idle increases.   PCM 10SXII and 10X owners will use the Retract switch to turn Idle-Up on and off whereas PCM 10SX owners will use the Brake switch.   Actually, any of the available switches can be used.

NOTE:  It is very important that the throttle linkage be Completely Free of binding and contain no slop for the Idle-Up to work properly.

    1. PCM 10SXII and 10X owners access code 17 and ensure he Aux5 knob is Active.
    2. Access an unused Program Mix, (code 51-53).
    3. Touch 10 to select Aux5 as the Master and touch 1 to select channel 1 (throttle) as the Slave.  Now touch ENTER to get to the next display.
    4. Touch PAGE to get to the switch selection display.  PCM 10SXII and 10X owners touch SEL under GER or GR to select the Retract Gear switch. PCM 10SX owners touch SEL under SW until BRK appears under SW, and also touch SEL under MASTER until ORIG appears.
    5. Now touch PAGE to get back to the first display (SXII and 10X owners touch PAGE twice).
    6. Rotate the Aux5 knob all the way Counter Clockwise and touch STORE under OFFSET. This should result in an OFFSET percentage of approximately  -86%.  This offset will limit the Aux5 knob so that it can only increase the idle and not decrease it.  It will safeguard against accidentally killing the engine by switching on Idle-Up.
    7. Flip your new Idle-Up switch back and forth and notice the display changing from POS-0 to POS-1 just above the percentages.
    8. Position your Idle-Up switch in the position (forward or back) where you would like the Idle-Up to be turned "ON".  Touch the + key until the percentage is 10%.  This represents the total percentage that will be mixed into the throttle when the Idle-Up switch is turned on and the Aux5 knob is rotated fully clockwise.
    9. Turn the transmitter and receiver ON.  Rotate the Aux5 knob fully clockwise.  Flip the Idle-Up switch on and off and check to make sure the throttle is moving in the correct direction. It should move towards the high throttle direction when turned "ON". If it is moving in the wrong direction, touch TURN under the percentages to change the percentage from positive to negative while the switch is in the ON position.  Check the direction again with the knob still fully clockwise.
    10. Make these final adjustments with the engine running. Rotate the Aux5 knob fully Counter Clockwise and set the Idle-Up switch to OFF.  Start the engine and get it up to operating temperature
    11. Access TRAVEL code 12 (10X owners touch ) and position the throttle trim lever in its center detent.  If the engine idle gets too low and the engine quits when the trim lever is positioned in the center, touch the "–" key under THRO to reduce the throw on the low-end until the engine does not die with the trim in its center detent.
    12. Making sure the engine stays up to temperature, adjust the low end travel using the + and – keys under THRO until you get the lowest dependable idle with the throttle trim in it’s center detent position.
    13. Now turn on the Idle-Up using your Idle-Up switch and slowly turn the Aux5 knob Clockwise to get the desired RPM increase (if the Aux5 Knob is too sensitive or insensitive, go back into the program mix and adjust the mix percentage down or up respectively).  Don't set the Idle-Up too high, or you may not be able to enter a spin but make sure it is set high enough so that the engine does not quit during a spin.
    14. Once you have the correct amount of Idle-Up, kill the engine and inspect the throttle linkage to ensure that the addition of throttle for Idle-Up does not stall the throttle servo at the high-throttle position.  Advance the throttle stick to full high and turn on the Idle-Up.  If the throttle servo is trying to drive the carb past full open and/or the throttle servo is buzzing, access TRAVEL code 12, (PCM 10X owners touch ) and touch the “-“ key until the throttle servo is not trying to drive the carb past full open when the throttle stick is in the full high position.
    15. Using the Idle-Up.  Prior to your take-off roll or just after take-off, turn the Idle-Up on.  Turn the Idle-Up off when you are ready to enter the landing pattern.  

Sometimes the engine will be hotter/leaner at the end of the flight and the idle will be too high or too low with Idle-Up turned off.  If this happens, keep the throttle trim lever in its center detent position and readjust the low-end travel (code 12) for the lowest dependable idle right after landing when the engine is still hot.  The low-idle should be adjusted to provide the lowest dependable idle for landing at the end of the flight rather than for taxi and take-off at the beginning of the flight.  You should be able to turn the Idle-Up off at the end of a flight and have confidence that the engine is running slow enough to provide good braking affect without quitting. 

You may find that on some days the idle is too fast or too slow with the trim lever in its center detent (air changes & pushrods sometimes expand/contract).  You can adjust the low-end travel in function 12, or, you can just move the throttle trim lever off center a few clicks and leave it there after the engine is warmed-up to operating temperature.  The Idle-Up will increase RPMs from whatever point the throttle trim lever is set.  Normally, once you have the Aux5 knob set for the desired increase in RPM, it does not require further adjustment provided that the low-idle is set properly.  Remember to turn Idle-Up OFF before attempting to land or you may sail right on by!