Pira.cz Technical Forum

FM Analysis => P275 FM Analyzer => Topic started by: mimu on November 22, 2020, 11:15:14 am

Title: 10.7 MHz input
Post by: mimu on November 22, 2020, 11:15:14 am
Hello.
Is it possible to modify the P275 analyzer and feed it with a 10.7MHz modulated FM signal? It would be interesting for measuring signals outside the band 87.5-108 MHz.

Thanks
Title: Re: 10.7 MHz input
Post by: Jan on November 22, 2020, 12:16:32 pm
There's a position on the board for pin header, marked as J16. This is effectively the 10.7 input @ 330 Ohms. For permanent use of this mode, the L12 coil should be removed from the board.

Please note that the device is optimized for FM broadcast (wide FM, bandwidth) so its ability to measure different services out of the FM band may be restricted.
Title: Re: 10.7 MHz input
Post by: mimu on November 22, 2020, 12:36:02 pm
Thank you Jan.
My intention is to use the P275 for measuring the deviation of the 10.7MHz output of a STL-Receiver on 2.4GHz.
Title: Re: 10.7 MHz input
Post by: Jan on November 22, 2020, 12:42:16 pm
If the 10.7 MHz signal is strong enough (> 1 mV), you may connect it directly to the standard RF input, while the unit is tuned down to 64 MHz.