It is a style I have used for many years. Why someone has to give it a name I have no idea, makes someone feel good I guess.
Anyway the main issue I am having is over-coupling between stages. I am winding coils as in the old Lynx/Argos designs etc. With interstage coupling done with coils on the same former. As the formers are relatively small/short there is not much distance to be had between windings so winding one winding of say 12 turns (anode) and then another at the top of 12 turns (grid) gives way to much coupling and the passband was something like 15 MHz, reducing the grid winding to 4 turns and placing this one over the anode coil at the earthy end has made things better, but with a loss in gain. The next attempt will be a 12 turn Bifilar winding, in the hope I get the gain back, without the over coupling.
Some will know that I have done work on a sync separator, line and frame timebases. I was only driving my HP scope to give a picture as a means to spur myself on, but in the end I had reasonable results: -
I will at the end need to find coil formers and screening cans I can buy, the idea is still to use KiCad and make myself a PCB's for the project.
Adrian.
Anyway the main issue I am having is over-coupling between stages. I am winding coils as in the old Lynx/Argos designs etc. With interstage coupling done with coils on the same former. As the formers are relatively small/short there is not much distance to be had between windings so winding one winding of say 12 turns (anode) and then another at the top of 12 turns (grid) gives way to much coupling and the passband was something like 15 MHz, reducing the grid winding to 4 turns and placing this one over the anode coil at the earthy end has made things better, but with a loss in gain. The next attempt will be a 12 turn Bifilar winding, in the hope I get the gain back, without the over coupling.
Some will know that I have done work on a sync separator, line and frame timebases. I was only driving my HP scope to give a picture as a means to spur myself on, but in the end I had reasonable results: -
I will at the end need to find coil formers and screening cans I can buy, the idea is still to use KiCad and make myself a PCB's for the project.
Adrian.
Learning as I go!
Youtube EF91 Valve
Youtube EF91 Valve
