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!!!!!

 

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.

 

Hello,

Here are some ebooks on RF technics.
http://www.rfzone.org/free-rf-ebooks/

I have noticed that some are not available anymore.
By putting the URL in the wayback machine they can be retrieved.
http://www.archive.org/web/web.php

Greetings,
Bertus