The name of DIRECTV

DIRECTV has been derived from Direct TV or DirectTV words

The origin of DIRECTV's name

The meaning of DIRECTV is just as the meaning of words Direct TV or DirectTV. The origin comes from the later two, as the company has evolved as the first high-power direct-broadcast satellite system. Therefore, for the branding purpose, "Direct TV" has become "DirectTV," and then finally DIRECTV to evade the double "T" which did not stand well within the single word.
There is a name for this grammatical change, referred to as "portmanteau word" which is a linguistic blend of words. A portmanteau word fuses both the sounds and the meanings of its components, as in smog, coined by blending smoke and fog,[2][4] or motel, from motor and hotel (from Wikipedia).

So, the meaning of it is correct in any of the three ways, but the right spelling is DIRECTV. Now, spelling and pronunciation are a bit different. While the word "direct" is pronounced as /dəˈrekt , dīˈrekt/, in the case of DIRECTV, the "direc" part is pronounced as /dəˈrek , dīˈrek/ and then simply TV /ˌtiː ˈviː/, all as one word.

At the end, if you were referring to this satellite TV service as "direct tv" or "directtv" you were not wrong (much). But the spelling and pronunciation is little different.