Ken:??Placement of the BFO freq relative to the IF passband will have an enormous effect on how the rig sounds on receive (and transmit!).??If your Si5351 is supplying both the BFO and VFO signals, you need to look at the frequency of?BFO?signal coming from the Si5351.? I am not using an Si5351 with my BITX40 module, but I measure the (stock) BFO freq at 11.9988.? That is -- as Fahan has said -- the "sweet spot" that produces really nice sounding audio for me.
If you are using the Si5351 for VFO only, another thing may be?happening:? Are you attempting to tune in signals?with the freq increment set at 100 Hz or lower?? if you have the increment set at 1kHz,?and if your Si5351 calibration is off (very common), you may simply be?a bit?"off frequency" when you?are tuning in.? Try it?at 100Hz?tuning?increment and tune it in by ear -- see if you can get?it to sound natural.? If you can, take note of hour?many Hz you are from a full integer kHz freq -- that will give you an indication of how far off your Si5351 calibration is.
I hope this helps
73? Bill N2CQR??
On Sunday, November 27, 2016 2:57 PM, "llah@... [BITX20]" wrote:
?
I'm going to try and play with a class D audio module with built-in programmable AGC parameters. This
coupled with a $3 arduino nano clone could make a nice up-grade for the BITX40?
WA6TKD
Adafruit Industries, Unique & fun DIY electronics and kits Stereo 2.8W Class D Audio Amplifier - I2C Control AGC - TPA2016 ID: 1712 - A mini class D wit...
