The issue with resonators and such is that they tend to wander.
This can sometimes on a few radios put a birdie right in the middle of an IF passband.
The uBitx IF got moved from 12 to 11mhz because of a particularly nasty case of this.
Jerry
toggle quoted message
Show quoted text
On Sun, Jan 3, 2021 at 03:12 PM, Shirley Dulcey KE1L wrote:
Reliable operation of an asynchronous serial link does not require a highly accurate clock; it only needs to be within 1% or so. That's easily met by a ceramic resonator. The CH340C is probably not even using one of those; it's using a reference on the silicon itself, perhaps helped out by a factory-programmed code for the specific chip. That's how the internal clock that is available on many microcontrollers works, including the ATMega328P which can be run without an external frequency reference.
Hide quoted text
