9MHz is pretty low, so we can treat the transistor as resistances, and capacitances (of which only drain output capacitance is of much importance).

Q1's gm is >12mS, so the input resistance is <80Ω. This isn't far from 50 so some padding may be needed to perfectly match things, depending on the exact JFET you get (gm might be up to 25, or more?).

C10 is -j800Ω and L9 is j56Ω, they don't seem to be filtering much of anything and surely only serve to unbalance the filter and add insertion loss?

L10 is fairly small (j186Ω in series with 330Ω) so doesn't do much of anything. Suggest more like 10uH and little resistance (more dynamic range?), or just resistance because who cares. (You might end up with the same for L9, i.e., using R15 for source bias directly, in which case you'd remove the bypass C9 of course.)

(Interestingly, as R15 rises, bias current and therefore gm falls, and eventually their parallel combination rises above 50Ω. As R15 falls, gm rises to a point (no more than the zero-bias value, of course), and R15 comes to dominate; eventually their parallel combination falls below 50Ω. Therefore, there will be some value where Rin = 50Ω. And this has to be R15 > 50Ω, since the source conductance is nonzero. If the JFET were well characterized, this could be calculated, but to get it perfect with any random JFET, you'll have to measure. Attach a transmission line in place of the diplexing filter, and adjust for maximum return loss.)

Q1 can drive any load. It's effectively a Norton AC source, i.e., a current source in parallel with some conductance and capacitance. This is where drain capacitance (~2pF) comes into play. Though at these frequencies, there's not much worry from a mere 2pF.

Indeed as drain conductance is very low, you could get massive gain out of this, still with pretty reasonable bandwidth given the low capacitance. This is done by raising the impedance seen by the drain. Like, 100uH RFC for bias, then either a matching network or transformer to bring the ~kΩ impedance down to whatever's needed (here, 500Ω, but it could be demonstrated into 50Ω for testing just as well). The, er, gain in gain, isn't strong -- it goes as sqrt(impedance ratio) -- but it's nice when you can take it for free.

But taking the simpler route, I would recommend either a ~500 ohm pullup, or RFC. Maybe both, so that you get some damping against the filter as well as some inductive reactance to cancel the filter's capacitance? Or just an RFC, sized to cancel the capacitance.

Note that the filter will only be ~500 ohms, heh well, if it has a lot of loss, or if its load is matched. (Also, 5.7uF inductors? Well, you did say it was 3AM...

)

Tim