A "Tevion HDD" is a DVD recorder?
You will be able to record off the Freeview tuner if its connected directly to the dvd recorder - for simplicity, use the RF leads.
(aerial - freeview tuner - DVD - TV).
Scart leads and sockets are'nt always wired-up the same so try using the RF leads just to get the DVD recorder tuned to the tuner.
You should also be able to record a digital channel whilst watcting a terrestrial channel - and vice versa.