Batboard

I have a Maratrac UHF 450-470 that I would like to increase RX sens around 441. Currently the lowest I can get it is about .5uV. Tried changing the aluminum slugs to brass/metal 6/32 screws, but that didn't help at all. Any suggestions? Maybe some caps need changed?, or am I s o l ?

You need to increase the inductance of the front end and injection coils. So you need ferrite slugs.