I've bought a few of these and this is the cheapest anywhere right now, a excellent HDMI modulator. Prime price.
Send 1080p High-Definition video with audio over an RF distribution system
Converts an HDMI signal into an HD digital Freeview DVB-T compatible signal
Connect multiple TM-RF HD to watch different devices
Upgrades an existing Standard Definition RF system to 1080p HD
Requires a DVB-T or DVB-T2 compatible TV