Cal Orr .com
ESC Diode Extension (single engine).... $30
ESC Diode "Y" Harness (twin engine airplane).... $45
Many ESC’s (Electronic Speed Control) have a BEC (Battery Eliminator Circuit) that allow you to power your receiver/servos from the motor batteries. This is done to save weight and ease of installation, charging etc. Be careful that you use a good quality BEC and you don’t exceed its current output with the size/number of servos.
With larger models, many people opt to use a separate receiver battery instead of the BEC, I would like to suggest that you can use both as a means of redundancy.
I like to use a BEC of 5.5 volts at a minimum of 4 amps. I then install a diode in the ESC’s servo connector (red wire) with the cathode toward the receiver. This means, due to the voltage drop of the diode the receiver will see just under 5 volts from the BEC at the throttle port. I then install a 5 cell (6 volt) battery with the normal switch harness plugged into the receivers battery port. My 5 cell (6 volt) battery is the primary source of power for the receiver/servos since its voltage is higher than that seen from the BEC. But if my 6 volt battery drops down then the BEC gradually steps in to help with the load. I figure if I have a BEC on board anyway, I will put it to work even if it is just as back up power.
Flying an electric twin engine airplane? You will have 2 - ESC’s and maybe 2 - BEC’s,
usually both ESC’s are plugged into a “Y” harness and then plugged into the receivers throttle port. In the throttle “Y” harness, add a diode to each leg of the “Y” in the red wire with the cathodes toward the receiver. The two diodes will allow each BEC to power the receiver/servos without the two BEC’s fighting each other. Again the voltage into the receivers throttle port will be about 5 volts. The primary power to the receiver/servos is from the 5 cell 6 volt battery through a standard switch harness to the receiver’s battery port..
NOTE: with either of the above systems, the BEC used must be 5.5 volt and the primary battery must be a good 5 cell 6 volt battery. The servos must be designed to operate on 6 volts.
Kraft receiver to JR/Futaba servos.....$10 ea
JR/Futaba receiver to Kraft servos.......$10 ea
2.4 Conversion- Operation & Order form
Do not use the transmitter without its 2.4 antenna.
Do not use Li batteries or batteries that are higher than 11.4 volts for the transmitter or 2.4 module.
Do not use the “Buddy Box” feature.
The telescoping metal antenna should be removed from the transmitter when using 2.4.
You need to adjust the 2.4 antenna so it does not point at the model when flying.
You may use JR/Spektrum receivers either DSM2 or DSMX.
JR (JR only not Spektrum) now has a new mode, DMSS and your transmitter will not operate these receivers.
Power on - Meter will move to the right and in a couple of seconds the transmitter will "beep" and the LED may flash. (The LED is seen through the transmitters meter.)
If the transmitter beeps continuously after you turned it on, turn the transmitter off then back on. This happened because the RF circuit came alive before the encoder.
The transmitter's 2.4 section has 4 modes of operation as indicated by the LED.
LED, off - DSM2 22ms frame rate.
LED, one blink - DSM2 11ms frame rate.
LED, two blinks - DSMX 22ms frame rate.
LED, three blinks - DSMX 11ms frame rate.
Note: If using the latter three, the LED pattern will repeat as long as the transmitter is on or the mode was changed with the bind button.
Note: The 11ms frame rate may make some analog servos jitter, use digital servos with high speed receivers.
The bind button has three functions;
#1 - If pushed and held when the transmitter is on, the RF output is significantly reduced. Use this feature as a range test. You need to get 30 paces (90') from your model. When the button is released the RF output is restored.
Note; while the button is held in, the LED is on
#2 - If pushed three times fast when the transmitter is on, the 2.4 section will step to the next mode of operation. If the output was DSM2 11ms (for example), the mode will change to DSMX 22ms etc.
(DO NOT PLAY WITH THIS BUTTON DURING FLIGHT.)
#3 - Used to bind Tx to Rx.
Bind - Tx to Rx
#1 - Plug bind jumper into bind port of Rx.
#2 - Power on Rx, LED(s) in Rx (and satellite receivers) will flash fast.
#3 - Set sticks (and switches) on Tx to desired fail safe. Neutral and LOW Throttle, trims too.
#4 - Push and hold bind button on the transmitter and then turn on Tx.
Note, your Tx should NOT be right on top of the receiver. Move away a few feet.
#5 - In a few seconds the flashing LED in the Rx (and satellite receivers) will be on solid and everything will operate. Release bind button.
#6 - Turn Rx and Tx off.
#7 - Unplug bind plug from Rx.
Note: The bind process usually selects the mode of operation in the transmitter for that receiver. If not, you may have to step through the different modes of operation for your receiver.
Note: if you are flying more than one airplane with your transmitter, you may bind all your airplanes (receivers) at one time. This means you will not have to rebind when you fly another airplane - just check servo reversing etc. For this to work, all the receivers must be the same mode - either DSM2 or DSMX, either 11ms or 22ms frame rate.
Turn on Tx first, it should beep then the LED will flash (unless DSM2 22ms was selected) indicating mode of operation
Turn on Rx, it will link in a few seconds with its LED(s) on solid.
* The Rx antennas (or satellite receivers) should be as far apart as possible and on different planes, one vertical and one horizontal.
* JR/Spektrum receivers have a high drop out (brown out) voltage of about 3.2 - 3.3 volts. Several servos can cause voltage dips in the brown out range. You may want to consider 5 cell 6 volt Rx batteries or if you are flying electric use a BEC of 5.5 volts.
Any Questions - Please ask.
If you have any problems with your transmitter or 2.4 conversion, I can help you get it working again. I WANT IT TO WORK FOR YOU!
I can not guarantee that any almost forty year old radio will continue to operate and safely fly a model! Yes I checked out the transmitter but that only means it worked when I checked it out - I might have missed something or there might be a component about to fail.
Send me one of your receivers (DSM2 or DSMX) and I will test fly your system in one of my airplanes.
Check with me before you send me anything..... or your radio could sit out in the snow/rain.
Send me your:
2) JR/Spektrum (DSM2 or DSMX) receiver
3) A check in the amount of $300
4) Signed copy of this order form.
I am ordering from Cal Orr a 2.4 conversion for my transmitter.
I further understand that there is NO guarantee or warranty of any kind that this system will continue to operate and safely fly a model!
Furthermore, no guarantee or warranty is extended to anyone else who may operate this system. I will be responsible for any or all liability resulting from the use of this system.
Signed _____________________________________________Date _____________________
Signature must match that of the check.
Do you have an ole favorite transmitter that you would like to convert to 2.4 ?
A 2.4 conversion to your transmitter will allow it to operate your JR/Spektrum receivers either DSM2 or DSMX. The transmitter is vintage, the airborne receiver/servos are modern.
I will also check out and adjust your transmitter for you at NO additional cost! Any problems I might find, I will discuss with you and can repair/replace.
Replacement transmitter battery pack...$60
Replacement transmitter joy stick pots (each)...$20
Replacement transmitter toggle switches (each)...$15
Send me one of your receivers (either DSM2 or DSMX) and I will test fly your system in my airplane.
Heathkit Transmitter --- New batteries, Converted to 2.4, ready to fly with your JR/Spektrum DSM2 or DSMX receivers....$600
If you want to stay on 72 Mhz and have a radio that needs to be serviced and stickered, I can help you with that also.
Looking for a Vintage Transmitter? Maybe I can help.
(Operation & Order form below)