Need a wiz to explain.
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Need a wiz to explain.
Can somebody please answer this for me.
I understand that all aircraft transmitters transmit at 75mhz and i understand mhz. But what is the function of the crystal?
I understand that all aircraft transmitters transmit at 75mhz and i understand mhz. But what is the function of the crystal?
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Need a wiz to explain.
Actually, here in the states, the predominant band is 72mhz. Most surface radios transmit on 75. There are some 75mhz aircraft frequencies, but not many.
The crystal is the item which tunes the transmitter (TX) and receiver (RX) to send/receive the signal on one specific freq such as 72.021 mhz. Think of it as a filter. Everything except the specific freq is filtered so that you don't transmit or receive the entire band.
John
The crystal is the item which tunes the transmitter (TX) and receiver (RX) to send/receive the signal on one specific freq such as 72.021 mhz. Think of it as a filter. Everything except the specific freq is filtered so that you don't transmit or receive the entire band.
John
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Crystal
The crystal that you purchase for R/C is usually in a little metal can. Inside the can are little 'holders' that touch the actual crystal material. When a voltage is passed between the 'holders' it causes the crystal material to vibrate very precisely. This vibration is passed on to the other parts of the radio circuit to be used to send the pulse information or to receive the pulse information which control our servos. Crystals are used because they are rather inexpensive, small and dependable for the accuracy of the frequency at which they vibrate. They are somewhat tolerant in the area of temperature and movement and are convenient in size. They are capable of vibrating at very high frequencies (such as our R/C frequencies) Different radio systems use crystals in different ways within their circuits so some crystals cannot be replaced by crystals from other manufacturers.