RF measurements and evaluation tests..

Discussion in 'General Electronics Chat' started by msoof, Aug 21, 2008.

  1. msoof

    Thread Starter New Member

    May 28, 2008
    hi all,

    i am involved in some tuner project and is looking at some RF tuner (FM and AM) design. The tuner circuitry involves stages like RF frontend (preselector and attenuation), mixer, IF filters, demodulation.

    i read up and found some info on the measurements and evaluation tests useful for tuner design. Examples are selectivity, sensitivity, gain distribution, gain variation, AM suppression, FM suppression, DC level, etc..

    However, the above keywords are all i know and there is not much info on
    - what is the purposes of these tests/measurements?
    - how to setup these tests and what test parameters are involved?

    Any help or links to informative sites will be greatly appreciated!!!

    Thanks in advance!!!!!
  2. studiot

    AAC Fanatic!

    Nov 9, 2007
    Most of the parameters you mention are measured with a wobbly oscillator (wobbulator) and an analogue oscilloscope.

    The wobbulator sweeps the input through the required range of frequencies and the output is observed on the scope.

    Also look up 'S curve' for aligning FM receivers.

    Find a good Radio Service Textbook.
    Foulsham (Sams) do some good ones.
  3. bertus


    Apr 5, 2008