When I connect the set up box directly to my HD3300 using the TV/VCR I only get the channel the TV uses. I have testing the cable that goes from the splitter to the PC and it works fine if I use it on the TV.
Thanks for the extra info.
Everything makes sense except the above statement.
When you say "if I use it on the TV" do you mean plugged into the TV and tuning Analogue on the TV or plugged into the STB and tuning Digital on the STB?
The TV/VCR output socket is only an antenna feedthrough so you would have to tune the digital tuner in the HD3300 to see anything. i.e. Exactly the same as plugging the antenna co-ax into the HD3300 antenna socket. You shouldn't see anything until the HD3300 has been tuned and it would be totally independant of what's on the TV.
It sounds like you are doing something wrong in setting up the HD3300.
I suggest going through the setup procedure again.
I use WinTV v7 with an HVR2200. Have you run the Setup Wizard for digital tuning? You should be able to tell it to use the DVB-T tuner and which country and region you are in then it will scan for channels.
The Signal monitor only works once the tuner has been setup and is receiving signals. Mine usually shows 27.7 - 30 in the SNR box. I can't remember how I setup Windows Media Centre as it was a long time ago.
One problem I do find is the Hauppage tuners are less sensitivew than 2 STBs I have and I get occasional pixellation and dropouts usually early evening even with full signal strength.
Do you have a UHF antenna only and not VHF as well and is the polarity of the antenna correct?