simple "digital" monoband transceiver SDT21

The goal of this project was the development of a simple to build CW monoband transceiver based on the direct superheterodyne principle with crystal control a la "PIXIE" or "Rockmite", but with much better technical data. To minimize the circuit effort, the concept should be as highly integrated as possible and realizable without hand-wound coils. Furthermore, for the SMD phobics, SMD placement was completely omitted this time. Despite these specifications, it was possible to fit the entire circuit on a double-sided PCB with dimensions of 69x52mm, which allowed it to be installed in the small TEKO A2 package.

The main focus of the circuit is based on the little known fact that digital inverters or gate devices of the 4000 CMOS series can be operated as analog amplifiers by a circuit trick, important here is the use of the unbuffered IC variant (index UB).

Please order the desired "set of band specific parts" according to the desired frequency!

Set of band specific parts to complete the SDT21 basic kit to a complete 40m monoband TRX!

 can only be ordered together with a SDT21 basic kit!

Set of band specific parts to complete the SDT21 basic kit to a complete 30m monoband TRX!

 can only be ordered together with a SDT21 basic kit!