Hi!
I've chosen the band because of the low frequency.
It's my first project, so I need something easy.
Idea was: just a radio w/ some SSB capabilities.
The current block diagram shows a double super...
That's how things go!
I got the drift of the oscillator down to a few Hz per minute.
The warm-up time is quite long though. But there is always something...
A good shielding is essential, as I discovered.
My oscillator uses varactor tuning, which works quite well.
At least after you take the simulation only as a (very) rough guide.
The varactor model isn't the best. And I've no clue how to make it better.
Attached the oscillator schematic.
The 2 BF199 drivers are still missing, I was eager to see it working.
The "counter" one is for a frequency counter - and general measurement point.
The lower "mixer" output is meant to go into the LO pin of a NE602.
The PLL thingy sounds interesting. Would be nice to read more about that.
So, one short stop at the bench before bedtime.
Had some 10.7MHz crystal filters in the mail today.
Cheers