The West relay contrapsion. This was a (not very well working) compromise as the normal CF739 preamp of Ron was broke. This preamp was mounted behind the cavity filter but was not unconditionally stable and oscillated a bit, measurements indicated NF = 0.3 dB and G = 26.5 dB (perhaps a bit too much?). It's an OZ2OE design but the limited selectivity doesn't work well with a GSM/UMTS mast (see next photo's) only 30m away (!)   (5/8)