Low band HF preamplifier : Design phase

Hi all,

I feel like building a HF preamplifier for the low bands (at least 40 and 80m), in order to increase the signals of the Flag antenna I'm planning to build.
The HF transistor( is a simpoe bipolar from NEC (NE46134), and the circuit has been optimized for high IP3 (> 40 dBm on both bands), with a gain close to 20dB. I use microwave office simulator.




There is just one thing Id like to clarify : On the output, I use a broadband transformer with a 1:1 ratio.
In most of the litterature I've read, this transformer has a higher ratio (Cf W7IUC preamplifier schematics)...

S-parameters S11 and S22 look quite well centered around 50Ohms, but am I correct ?
I also simulated a band-pass-filter at the input of the preamplifier, and over-all gain curve versus frequency looks like :













































IP3 has been simulated to be over 40dBm on both bands, Gain is 20dB on 80m, and 21dB on 40m.

HF filter has been simulated using RFSIM99 and here it is :
































What else should I take care of?