All this is possible with the new Signal Predator from Elenos :
https://www.elenos.com/signal-predator/
At the end of the page you can see the streaming of one Signal Predator working live on the field .
Or you can use this link : http://www.freewaves.it/fmt.html
One of the most challenging measurement is the stereo crosstalk of a stereo analog signal .
Just to give you an example a very small impairment of amplitude response of +/- 0.07 dB in amplitude and phase of +/- 0.45 ° between 30 Hz and 53 kHz do not allow the stereo crosstalk to be better than 45 dB !
Just check for reference at page 9-10 the document :
https://www.americanradiohistory.com/Archive-Catalogs/Broadcast%20Electronics/BE-The-Composite-Signal-Key-to-Quality-FM.pdf
Now also the transmitters tipically use digital generation of the analog FM signal , so I have checked the crosstalk of the stereo signal generated from an Elenos ETG Indium Digital series connecting the RF monitor of the transmitter to the input of the Signal Predator .
The values measured from 30 Hz to 15 kHz was equal or better than 75 dB .
With this values it is hard to say if the limit depends on the transmitter or on the Signal Predator .
This order of magnitude of measurements so far was only possible with huge instruments with very huge costs , only possible to big broadvasting companies , while the cost of a Signal Predator is affordable from many companies and people .
Another measurement of tremendous impact for a Radio Station is the live measurement of the Signal to Noise Ratio in the Audio demodulated signal with NON NEED TO INTERRUPT THE PROGRAM .
This allows to continuously monitoring the quality of all the FM Stations , locally or on air .
Signal Predator also display , together with the Stereo Pilot and RDS modulation deviation , the constellation of the RDS BPSK symbols :
I understand now the reason why the Signal Predator advertising says :
" BORN TO BE DIFFERENT " .
The measurements screens of the Stereo Crostalk are as follow .
The crosstalk between the L & R channels are the difference of the audio carriers between the two white traces at 30 - 1000 - 5000 - 15000 Hz .
