You haven't given enough information.

First, I would need to know if you get any STRONG channels, and if so,
what channels are they? Second, exactly which channels are you trying
to improve?

There is a big difference between improving VHF signals and UHF
signals. You mentioned channel 49. To begin with, NO all-channel tv
antenna on the market has anywhere near the gain of the 8-bay bowtie
Channel Master UHF antenna. As mentioned by others, a pre-amp at the
antenna only PRESERVES the existing signal (most of it) received by
the antenna - the amp increase in signal level is there to compensate
for long leadins. It does NOT increase the signal-to-noise ratio.

With a Channel Master 7-foot parabolic UHF antenna, I have picked up
channels nearly snow-free that I couldn't get at all with the hugh
Channel Master 1160A, their top-of-the-line (no longer manufactured)
VHF-UHF antenna. And the 8-bay UHF antenna greatly improves UHF over
any VHF-UHF antenna on the market.

The problem I have experienced using a pre-amp at the antenna is
overloading the local signals which then totally wipe out the distant
channels I was hoping to improve.

For VHF (channels 2 - 13), you will double your gain (3 dB) for every
ten feet you raise your antenna. This is a "rule-of-thumb" but not
always true since television reception depends on many variables. For
UHF, sometimes higher is better, but sometimes lower is better. When
I lived in Northern California, I had the big Channel Master 1160A
mounted on a 40-ft mast with rotor and could NOT get channel 14. But
my neighbor, with a cheap antenna mounted on the chimney picked up
channel 14 loud and clear. I now live in Central California where
most of our stations are on UHF. I have seen people walk all over
their roof tops holding their antenna to find the best spot.
Sometimes one or two feet left or right, up or down, makes a big
difference in UHF reception.

Without knowing more, I'd say your best bet is the largest VHF antenna
you can safely mount along with the Channel Master 8-bay bowtie UHF
antenna, using separate leads (shielded coax) and a rotor to turn the
antennas, mounted as high as practical. My current setup is the
Channel Master 1160A with the 8-bay UHF on top, mounted on a 20-foot
mast with rotor. On a consistent, regular basis I get excellent
reception of channels up to 100 miles away, and often get excellent
reception of channels 180 miles from me. And sometimes get fair to
good reception up to 300 miles from me. NOT SKIP.

Gary Arnold, author
HOW TO SELECT THE BEST TV ANTENNA
RADIO ELECTRONICS MAGAZINE - AUGUST 1982