[amsat-bb] LoRa modules sx1276

[Nick Pugh]

I have been playing with Lora radios SX1276 on 145 Mhz. The spec sheets
reports sensitivities of -148 dbm with a bandwidth of 7800 hz and a
spreading factor of 12.   I am unable to get close to this spec when place
in a link with antennas.  I suspect that at my location there has external
noise on the antenna. When I test the module at UHF they meet the
sensitivity specs.

 

My idle noise on the antenna no signal is -120 dbm and the noise terminated
into 50 ohms is -127 dbm with a bandwidth of 10 khz. I have 2 questions?

1.	What is the noise temperature of the antenna?
2.	How can I express the reduction in sensitivity of the Lora radios
with antenna temperature?

 

Nick Pugh K5QXJ

 

 

 

 

 

 

 

nick

 

Cell      337 258 2527

 

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