May 10, 2007 #1 7 7rots51 Advanced Member level 4 Joined May 17, 2002 Messages 1,183 Helped 25 Reputation 50 Reaction score 12 Trophy points 1,318 Activity points 9,636 hello what are the FM demodulator methods?(for voice or FSK data) Can you send some links or pdfs?
May 11, 2007 #2 A alexx Junior Member level 2 Joined Feb 21, 2003 Messages 23 Helped 6 Reputation 12 Reaction score 0 Trophy points 1,281 Activity points 211 https://www.qsl.net/vk2dq/reading34.pdf https://www.tpub.com/neets/book12/51c.htm **broken link removed**
https://www.qsl.net/vk2dq/reading34.pdf https://www.tpub.com/neets/book12/51c.htm **broken link removed**
May 11, 2007 #3 flatulent Advanced Member level 6 Joined Jul 19, 2002 Messages 4,624 Helped 489 Reputation 980 Reaction score 151 Trophy points 1,343 Location Middle Earth Activity points 46,689 There are several standard methods. PLL works best at low SNRs Phase shift and multiply by the original signal. The shift can be done with a LC network or a delay line. Pulse counting is the most linear but requires very high SNR. The RF cycles trigger a fixed duration monostable and the output is low pass filtered. Then there are the LC networks with diodes used in the early days.
There are several standard methods. PLL works best at low SNRs Phase shift and multiply by the original signal. The shift can be done with a LC network or a delay line. Pulse counting is the most linear but requires very high SNR. The RF cycles trigger a fixed duration monostable and the output is low pass filtered. Then there are the LC networks with diodes used in the early days.