acamus,
I took the opportunity to look up
Your Chart
And I'm sorry to tell you this, but I've definitely seen better !
Just to clarify...
The Column marked "Real", is the Channel Frequency Number, that the Antenna actually has to be able to receive.
The "(Virt)" column, are the numbers you enter into your Remote/Tuner, to select that channel.
You can blame the FCC for that, but, it's the way it's done.
An Antenna should always be selected, according to the Frequencies listed in the "Real" Column of your Chart, for your specific location.
So, given what I see in your chart, you MUST have an Antenna which at least receives Channels 7-69, but, if you have a Full Range Antenna Ch 2-69. that would work too.
Do you know what kind of Antenna you have ?
If not, maybe you could attach a picture of it, and someone may be able to identify it for you.
I think your choice to add an Pre-Amp to your system, was a good idea.
However, given that we don't know what the output(s) are for the V-III, I may have suggested the...
ChannelMaster AP-8780
I was under the impression, that the V-III Amp, had only One Input for the Antenna, but TWO Outputs (like for two TV's) and that it supported both VHF and UHF.
So to re-cap what you need to do...
1) Get us the Make/Model of your Antenna, or, a Picture of it.
2) Tell us if the wire you're using on the V-III is 300 ohm (Flat Cable) or Coaxial.
3) Look at the V-III, or the Paperwork for it, and see if there are separate inputs for VHF and UHF, or just one input, and one output.
4) Then IF there are separate inputs for VHF and UHF, which one do you have your Antenna connected to.
One other thing...
Are you sure that you're Aim is directly on the Channel. Do you have a Compass, and are sure that the Antenna is on 45° Magnetic ?
I apologize for my redundancy, the other Contributors to this issue, having said the same thing. But, I thought it may be helpful to offer a step by step approach .
Have a good Day !
S.W.