radium98 wrote: ↑
Sat Aug 15, 2020 3:50 pm
wonderful work sinus keep things up ,but i have a little question how you connect the aerial for reception.you tap the coil ?
According to the note on his diagram, he taps the input coil 1½ turns up from earth for the aerial input. It'll work, but the sensitivity won't be spectacular.
I used to use dual-gate FETs in my receivers - the extra gate can be used for mixer injection or for gain control. I'll scribble up my circuit, and see if I can locate the PCB artwork. I also used a sophisticated PLL demodulator at the back end of the CA3089 IF chip - this gave an extra bit of sensitivity, and would excavate weak signals from noise! The PLL demodulator is subject to a Patent (look it up if you really want to use it), so I won't post it here (until the Patent expires in 2024).
The front end really works well, and if sensibly constructed will be sensitive, stable and selective, and doesn't suffer from de-dense problems in proximity to big rigs. I'll get scribbling shortly.