RegLna

Started by mav, January 26, 2014, 07:05:54 AM

mav

Hi All,

According to the RF69 datasheet the value of the RegLna register is default 0x08 from startup (input impedance of 50 Ohms), but the recommended value is 0x88 (input impedance 200 Ohms).
I thought I'd do a small experiment to see if RX is better with 0x88.
I have done the experiment with a RFM69HW and the received RSSI is consistently 7-8 dBm better with RegLna = 0x88
Since the antenne arrangement is different for a RFM69W I don't know if this will be true for a RFM69W as well.

I don't have a RFM69W at the moment, so I was wondering if someone could run a test with a RFM69W?

Marco

Felix

Hmm... I tried setting REG_LNA to 0x88 (ZIN=200ohm, current gain=1) and didn't notice a difference  :-\
Maybe someone else can give this a try as well and let us know the results ... ?

hdphilip

QuoteHmm... I tried setting REG_LNA to 0x88 (ZIN=200ohm, current gain=1) and didn't notice a difference  :-\
Maybe someone else can give this a try as well and let us know the results ... ?

i notice about a 6-7 dbm difference also with REG_LNA to 0x88 on the 69hw board

Philip