# GnuRadio FM Receiver: Heterodyne vs Xlating vs Direct

I'm trying to build an FM receiver (and eventually transmitter) in GnuRadio that will be able to interact with my local repeater. Starting with WBFM (because I can consistently pull in broadcast stations for testing) I created 3 receivers:

• Directly tuning my SDR hardware to the station I want to listen to
• Tuning the hardware to some base frequency, then multiplying by a cosine; heterodyne
• Tuning the hardware to some base frequency, then using the Frequency Xlating FIR Filter

My question is, which is the better method given I eventually want narrow-band FM with split transmit & receive against a repeater?

I'm guessing having to change the hardware's frequency from receive to transmit, then back again will be "too slow". I'd think that going back-and-forth between cosine sources wouldn't be too bad, but I'm wondering if there is an advantage to the Frequency Xlating FIR Filter. Thoughts or advice? Thanks!