The CW Kit from QRP-Labs is a very capable transceiver and the performance matches just about anything available on the market.
There is a small problem, however, with the fact that it is a single-band device. So when I stared out I built a 20m unit which has been remarkably fun when the bands are open, but mother nature isn’t always kind to us and often times there was just no signal to play with.
So, I investigated what is required to change it down to 40m. Turns out it isn’t a lot. A few toroids, a few caps. Most of the components can be desoldered without hassles. My initial take is that the following components are affected:
| 20m | 40m | |||
| L1 | 0.77uH | 16 | 1.4uH | 21 |
| L2 | 0.90uH | 17 | 1.7uH | 24 |
| L3 | 0.77uH | 16 | 1.4uH | 21 |
| L4 | 0.40uH | 10 | 1.0uH | 16 |
| C25 | 390pF | “391” | 680pF | “681” |
| C26 | 390pF | “391” | 680pF | “681” |
| C27 | 180pF | “181” | 270pF | “271” |
| C28 | 180pF | “181” | 270pF | “271” |
| C30 | 30pF | “300” | 56pF | “560” |
| C5 | none | none | 40m | 39pF |
| C8 | none | none | none | none |
| T1 | 3t x 3 | 30t | 5t x 3 | 38t |