UHF on a VHF Rig

This circuit enables fair copy of strong 444 MHz signals, off a local repeater, using a 2m rig and an indoor 70cm ¼λ ground plane antenna.

UHF Converter 
The 300 MHz 5th harmonic of the local oscillator, mixing with the incoming signal, delivers output on 144 MHz.

UHF Converter - Schematic
The enclosure is a plastic trinket box reworked to fit two BNC sockets plus one RCA for the DC supply and also to screw the cover in place.

UHF Converter - inside view
The converse (VHF on a UHF Rig) is also possible by just changing over to a 2m antenna and a 70cm rig.