This converter for WWV time reference station signals was found at Popular Electronics. The 15 MHz signals are now received on a medium wave radio at 1 MHz.
This is a high efficiency version with the MC723 which is the Motorola version for this well-known...
This circuit was found in the March 1997 Electronics Now magazine. It uses a common analog...
This circuit is from an 80's documentation. It makes use of two SCRs with current capacity...