Presuming that the existing TV has support for ATSC (digital format for OTA), ADTech is correct to question it's performance. Be sure that you have set the tuner to scan for ATSC channels, not the common default of cable (QAM). If the tuner is not set correctly, you'll never see any OTA signals.
If that fails and you don't have access to a newer tuner, the $40 HomeWorx HW-150PVR is a very good set top tuner that has full HD capability along with many other useful features.
http://www.amazon.com/Mediasonic-HW-.../dp/B00I2ZBD1U
The VHF only YA-1713 should be able to deliver real CH-13.