Very cool, sounds like you added a 4mhz crystal filter for CW in parallel with?
the 12mhz crystal filter for SSB as suggested by Farhan here:
? ??
/g/BITX20/message/36041Further discussion here:
? ??
/g/BITX20/message/36549? ??
/g/BITX20/message/36947You might describe exactly what you found to work, posting code and schematics.
Maybe a quick description of what crystals you used and how they were matched.
Did this in any noticeable way affect performance when using the 12mhz SSB filter?
There's a bunch of CW operators in the forum who might be interested in
duplicating your efforts.
Jerry, KE7ER?
??
On Wed, May 9, 2018 at 02:42 am, Alex - PA1FOX wrote:
Hi ubitx fans,
This is a follow up from my original message of February 22nd.?
I finally managed to find the root cause of the interference. Having replaced the Nano serveral times, the SI5351 Adafruit breakout board and ending up building half of the digital circuit next to the ubitx in breadboard style. I then eliminated all functions in the firmware of the nano one by one to figure out if I just could set the frequency on the display and the SI5351 without any interference. This worked.
The cause was a software issue. I have added a menu function to change the CW band width from wide to narrow and back. During all the test work I had not linked this software addition to the noise I got in the receiver. During the tuning process, at every frequency change, the function was called and set the correct? IF oscillator frequency to 4Mhz or 12Mhz (dependant on wide or narrow). As this frequency was set again and again with every tuning step this was causing the audio clicks. I now changed the function to check if the frequency is already correct and need not to be set again.
All clicks gone. Pfew, that one got me puzzled for quite some weeks. As often, the issue and solution are very simple as soon as you've discovered them.
I will throw in a youtube video shortly showing the effect of wide and narrow in CW with the ubitx. it's huge!
73, Alex
PA1FOX
