Re: Broadcast FM duplicate image at +240mhz
Posted: Fri Mar 04, 2016 11:18 pm
I have the same problem receiving FM broadcast stations around 330 MHz (offset +240 Mhz).
An other (but less strong) mirror is around 50Mhz (offset -45 MHz).
In my opinion this could be cured by implementing better bandfilters in the SDR-PLAY.
The bandfilter for the 330 mhz band has a low reject for out off band signals.
I cured this with the "88-108 MHZ band reject filter" sold by gr_makis66 (SV1AFN) on ebay.
It works perfectly. Also it is so small I will build it into the SDR-PLAY housing using a pair of SMA male/female pigtails.
PE1OSQ
An other (but less strong) mirror is around 50Mhz (offset -45 MHz).
In my opinion this could be cured by implementing better bandfilters in the SDR-PLAY.
The bandfilter for the 330 mhz band has a low reject for out off band signals.
I cured this with the "88-108 MHZ band reject filter" sold by gr_makis66 (SV1AFN) on ebay.
It works perfectly. Also it is so small I will build it into the SDR-PLAY housing using a pair of SMA male/female pigtails.
PE1OSQ