It appears Panasonic are skirting the issue, digital does not need a stronger signal than ntsc, old rf chns, since digital needs less signal to noise ratio, etc.

QAM (quadrature amplitude modulation) is a method of combining two amplitude-modulated (AM) signals into a single channel, thereby doubling the effective bandwidth. QAM is used with pulse amplitude modulation (PAM) in digital systems.

ATSC uses 8vsb modulation.

All tvs have both types of demodulation capacity in a tuner, since they have to work for cable (QAM) and OTA ATSC. MOST set top boxes also do both, mine does.

I have in attic mouted uhf yagi, 50 feet co-ax, then a pre-amp in basement, split 4 ways. (amp in basement easier to get at etc.) Furthest distance to NBC is 90 miles (Buffalo) shooting thru Toronto CN Tower 10 miles away inline with Buffalo stations.

Suggestion, an 8 bay bowtie pointing 143 degrees, back of antenna more or less to local stations and a pre-amp of about 18 dB should be all you need.

Look for low cost antenna and pre-amp, all should work. Mind you it can still be a hit and miss, fine tuning always required.

Update: Suggest pointing antenna to about 120 degrees first, local channels will come in off the side or a little of the back, the antenna gain will be reduced in this direction by at least 15 dB or more, the pre-amp will cover this loss and since locals are lower in rf signal strength, the pre-amp should not over load.

If thhe 8 Bay is too large, you can always try with a 4 bay antenna at first. Why oversize if not needed. However, winter rf reception (no leaves on trees will be different than summer) also the roof material with snow/rain will attenuate the signal up to 10 - 15 dB and will vary.

Overall best is outside antenna. I will go this route myself next spring.