I have build the driver. It seems to work fine.
I used a 1350p as variable gain amplifier. The signal out of the 1350p is amplified by a MAR2.
Finally the signal is boosted to 10 milli Watt by a vhf power transistor that I happened to have. A 2n2219 would do as well. It works in class A
The signal is detected at the collector of the vhf transistor. This signal is fed back to the 11350p input.
After some fiddling with components values the output was constant between 1.8 and 30 MHz.
I have applied a 2 tone signal. to test the linearity. It looks good on the scope. I have repeated this test on all HF bands an 160 meter. It looks good at all those bands.
I have to test how the signal sounds when real speech is used. This concept works a speech compressor. So I have to use real speech to test it. I don't expect problems. I may have to play a bit with the attack and decay times. Now it has fast attack and slow decay.
The amplification is quite high. I only need a few millivolts to get 10 milli Watt. The signal out of the bandfilters is about 10 times stronger so I need some attenuation.
