Allison, Nick, all,
This might be of interest
I managed to find a couple of 2N5019¡¯s and put them into my proto driver board (ie Q90 to the push-pull FET driver stage)
The other stages have MPSH10¡¯s with the emitters bypassed with 220pF. The final PP 2N5109 stage using the standard parts.? Ie 22R emitter resistors etc. BUT, I placed a 10R in parallel with the 22R emitter res.
Input level ~ 35mV rms, RV1 at maximum.? 10R added across the 22R emitter Res. Giving about 6.9R
¡¤???????? 160M???? 916mW out
¡¤???????? 80M?????? 994mW
¡¤???????? 40M ????? 943mW
¡¤???????? 20M?????? 837mW
¡¤???????? 10M?????? 663mV
¡¤???????? 6M???????? 364mV
I then decided to boost the high end by bypassing the emitter resistor with about the the same Xc value.? A bit under 900pF so I used 1nF which was to hand.
Results
¡¤???????? 160M???? 908mW
¡¤???????? 80M?????? 950mW
¡¤???????? 40M?????? 960mW
¡¤???????? 20M?????? 1.05W
¡¤???????? 10M?????? 1.02W
¡¤???????? 2M???????? 980mW
This obviously boosted the top end quite well.
The gotcha of course is that this was tested with a 50R output load, which will not be the case with the FET¡¯s connected.? Since I have no FET¡¯s to try this, I can¡¯t go any further.
Glenn
Vk3pe
