Author Topic: fonction AM  (Read 2669 times)

radiobel

  • Newbie
  • *
  • Posts: 6
fonction AM
« on: July 10, 2014, 09:32:24 am »
Hello, what  is the function of the line " AM: " on the pira please?
Thank you

Jan

  • Hero Member
  • *****
  • Posts: 560
Re: fonction AM
« Reply #1 on: July 10, 2014, 09:48:40 am »
It is a detector of Amplitude Modulation on the signal being received. Its purpose is to detect multipath propagation which may affect FM deviation measurement.
The AM on the received signal may occur for various reasons, including but not limited to transmitter failure, broadcast antenna coupler, motion, interference, multipath propagation and other characteristics of the environment. In general the AM modulation of the signal is undesirable. Thus whenever possible the user should choose such antenna placement and direction that maintains a low or zero AM level. AM below 15 % has usually no effect on the FM deviation measurement.

radiobel

  • Newbie
  • *
  • Posts: 6
Re: fonction AM
« Reply #2 on: July 10, 2014, 12:47:21 pm »
merci beaucoup.