This thread is becoming aged, and
@Rakesh nampalli is probably a drive-by poster who is no longer monitoring the thread. I will reply anyway because I have little else to do right now.
AFAIK, 27 MHz was reserved for CB radios and was NEVER used for FM communications, narrow-band or conventional, although individual CB channels were (usually) crystal controlled, as
@Rakesh nampalli appears to be trying to do.
Back in the day (about the middle of the 20th century) crystal control was necessary to guarantee sufficient separation between CB channels to avoid interference among adjacent channels. This made the CB radios of early adopters very expensive because a pair of crystals (one for receive, one for transmit) was needed for each of the original CB channels. Later, a single crystal was used with frequency synthesizer circuitry to provide operation on every CB channel. Still later, some CB rigs incorporated single side-band or SSB modulation, which is a form of amplitude modulation (AM) exactly like the original AM CB standard, except the carrier frequency and one of the two (identical) side bands was suppressed during transmit. This was supposed to double the number of available channels, but I don't think it was ever very popular. And, as far as I know, there was never any FM modulation permitted in the 27 MHz CB radio band.
Cell phones and portable GPS pretty much eliminated any requirement for CB by previous owners of CB radios... unless you happen to be stuck out in the boondocks with nary a cell phone tower visible anywhere. If that happens, you either need a (very expensive) Iridium satellite telephone, or a radio amateur license and transceiver rig with which to communicate.
So, please, do tell us why you are trying to design and build a 27 MHz FM two-way (transceiver) radio? Unless you are very careful, whatever you put "on the air" at this frequency, and with that modulation scheme, will be illegal and make you subject to heavy fines and possible imprisonment after your transmissions are detected, located, and you are arrested. If your devices actually interfere with licensed radio services, it is almost certain you will be discovered and prosecuted. So, please tell us what you are trying to DO. Do not describe how you think you should do it. People here will give you advice about that. Just tell us what you are trying to DO.
