The assembly instructions are clear, and the silk screened printed circuit board makes placement of components straightforward. Stage operation throughout construction can be checked with strategically placed tests using a multimeter. Two transformers were missing in the original shipment, but Small Wonder replaced them with no hassle. The only serious challenge was winding the four toroids, but a careful count of the turns reduces the chance of error.
Small Wonder recommends using Digipan to align the transceiver and for subsequent operation. I prefer Ham Radio Deluxe, so after alignment with Digipan I set up for operation with HRD.
With only 3 to 4 watts output, making a QSO requires patience. Not only that, but my vertical multiband antenna is hardly ideal for QRP operation. Nonetheless, my patience was rewarded with a contact -- AJ4YM in South Carolina (470 miles) . In quick succession I racked up contacts with K9AAN (500 miles), NS2C (840 miles), and VE4KZ (1207 miiles). And through PSK Reporter I can see my signal reaching the West coast, about 2400 miles from my QTH in central Pennsylvania.
It took me about a week's worth of evenings to build the PSK-20. Now, every evening -- and a lot of weekends -- are filled with my latest self-imposed challenge. Making a QRP contact with Europe!