[amsat-bb] 70cm LNA

[Zach Metzinger]

On August 9, 2020 4:57:21 PM CDT, Zach Metzinger via AMSAT-BB <amsat-bb at amsat.org> wrote:
>I've ordered some 433MHz SAW filter (RFMi) from Mouser to install at
>the output of my homebrew LNA. Hopefully this will reduce overload of
>the FT-847. A FCDP+, with it's internal SAW, works very well with that
>antenna and LNA, so I think I'm on the right track.

Success! The SAW filter eliminated the offending cell-tower sources. The noise floor barely moves when the preamp is switched in, while the desired beacon signal increases significantly.

I will be attempting to measure the NF with the Y-factor method. 

The exact filter used was SF2446E 
(Digikey 2410-SF2446E-ND).


--- Zach
N0ZGO