LNA challenge - observation signal degraded

I’ve been receiving fairly good observations from various satellites with my RTL SDR based station (Number 680 M0RSX) for a few months so decided it was time to add a LNA into the feeder. I purchased one of the SPF5189 based units from ebay. The feeder from the antenna is connected to the SMA connector marked RFin, the SDR to RFout. The LNA says voltage 5v so that’s what it’s getting. The first observation shows significant signal loss compared to an observation with no LNA. Any thoughts on what I’ve done wrong please?

You probably have ended up with too much gain in your system, resulting in distortion at your receiver.

Adding a LNA isn’t just about increasing signal levels, it’s about increasing system sensitivity. It may sound counter-intuitive, but you will most likely need to back off the gain in your RTLSDR.

The ‘Setting the gain’ guide walks through a method of setting the gain appropriately, such that your system ends up being limited by whatever local noise you have present: https://wiki.satnogs.org/Omnidirectional_Station_How_To#Setting_the_gain