General Receiver

Q. What is the difference between Dual Conversion and Single Conversion?

A. A single conversion receivers have only one "mixer" stage. The receiver takes the incoming signal and mixes it with the local oscillator signal. The different frequency is then amplified as the Intermediate Frequency (IF) and detected for use. The draw back with single conversion is that there is a chance of "image" reception. This is where, depending on the receiver tuning, the receiver will pick up an image of another frequency at either the high or low end of the band. A dual conversion receiver has two mixer stages and two local oscilators. This eliminates the chances of image reception. Dual conversion also allows for better interference rejection.

Q. What is causing my receiver to act erratic when I run the engine?

A. After a crash or hard landing, the ceramic filter can become damaged. This is the most common cause. To prevent this, Hitec suggests using the supplied Flight Preserver and mounting the receiver away from the fire wall of the plane. If your receiver is vibration sensitive, send it in to the service department for repair.

Q. Can I change the frequency on my receiver?

A. Hitec receivers are center aligned so you can change the frequency easily. When changing the frequency, be sure that you change it with the same type of crystal (dual or single conversion) and that it is in the same band (27, 72 or 75MHz). Use only Hitec crystals.

Q. My antenna broke, what is the proper length?

A. Antenna length depends on the frequency band. Below are the common bands and the length associated with each: 27MHz - 22 inches
72MHz - 42 inches
75MHz - 22 inches

Q. Do I have to plug the battery into the battery slot?

A. You can plug the battery into any open channel.

Q. What is Positive and Negative Shift?

A. The positive or negative shift mentioned pertains to FM receivers. The shift is the way the FM signal is modulated. For Hitec and Futaba the shift is negative. Airtronics and JR are positive shift. Because the modulated signal is different, you cannot use a negative shift transmitter with a positive shift receiver or visa versa.

Q. What is BEC?

A. BEC stands for Battery Eliminator Circuit. What this circuit does is take a 7.2 to 8.4V battery pack and reduce the voltage to 5V. This allows the receiver to operate properly. This circuit is mostly used in conjunction with a mechanical speed control.

Q. What crystal do I use with my receiver?

A. The crystal required depends on the receiver. Please refer to the table below. Hitec organizes receiver crystals according to pull tab color and part number.

Note: XX = Channel Number

Part Number Frequency Band  Designator  Color Code  Single or Dual Conversion  Receivers 
 66727XX  27 FM  RF  Blue  Dual -DCX
 66772XX  72 FM / AM  RF  Blue  Dual -Supreme
-Super Slim
 66775XX  75 FM  RF  Blue  Dual -DCX
 66427XX  27 AM / FM  RA  Green  Single -HAS03MB
 66472XX  72 FM / AM  RA  Green  Single -Feather
 66475XX  75 AM  RA  Green  Single -HAS02MB
 66875XX  75 AM  RS  Red  Single -HFS03MM