That USB port on the front panel has already come in handy. I needed to switch the tuning increment from 1 kHz to 100 Hz. I just went into the Arduino program, removed one zero, and then re-uploaded the code.
I also put to use the sideband inversion rule-of-thumb: My IF is at 9 MHz. I want to receive signals in the 7.2 MHz range, and I want the VFO running ABOVE the IF frequency. So obviously the VFO will be running at around 16.2 MHz. So, rule-of-thumb time: Will I be subtracting the frequency with modulation from the frequency without modulation? Yes I will! So, there will be sideband inversion. This tells me where to position my BFO frequency. The signals on 40 start out as Lower Sideband. But as explained above, by the time they get to the filter they will be inverted and will be upper sideband signals. So I need to put the BFO slightly BELOW the filter passband so that I can tune the signals in such a way as the sidebands fit into the filter passband and have the proper frequency relationship to the BFO to allow for demodulation. I put it at 8.9986 MHz. With the Si5351, changes to the BFO and VFO frequencies are very easy.
In response to popular demand, "SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
For the print version:
For shipping from a printer in the U.S. (probably better for N. American buyers) Click here: SolderSmoke USA Version
For shipping from a printer in the UK, Spain, or the USA (probably better for UK and other European buyers)
Click here: SolderSmoke EU Version
The two versions are identical, except for a minor difference in the paper used. That's why the prices are a bit different.
Bill's OTHER Book (Warning: Not About Radio)
Click on the image to learn more
W4HBK's QRSS Grabber: The Amazing Pensacola Snapper (Live!)