An antenna is one component in a chain. Signal has to reach it, get through the cable and connectors, survive any splitters or amplifiers, and arrive at the tuner. A weak result can come from any link — which is why replacing the antenna so often changes nothing.
Aim and height
Direction matters more than price. A modest antenna pointed correctly beats an expensive one pointed wrongly. Height helps because it clears obstructions. If reception changed after someone moved or knocked the antenna, start there.
What sits between you and the transmitter
Buildings, terrain and dense foliage all attenuate signal. Trees in particular can make reception seasonal — fine in winter, poor once they are in full leaf. If your problem appeared gradually over spring, that is a strong clue.
Cable
Cable is a quiet failure point. Kinks, crush damage, staples driven through it, and water ingress at outdoor joints all degrade signal without any visible drama. Cable runs that are much longer than necessary also cost you signal.
Connectors
Loose, corroded or poorly fitted connectors are extremely common and cost very little to put right. Check every junction, especially outdoor ones.
Splitters
Every split divides the signal. A feed that was adequate for one outlet may be inadequate once it feeds three. If your problem started when an extra outlet was added, that is almost certainly the cause.
Amplifiers
Amplifiers are not a general cure. Applied to a clean but weak signal they help; applied to a noisy signal they amplify the noise too, and applied to an already strong signal they can overload the tuner and make things worse.
Some channels but not others
This is diagnostic. Losing part of the lineup while keeping the rest usually points at aim or frequency band rather than a dead antenna, because a failed antenna tends to take everything with it.
Still stuck?
Call a product specialist and describe what yours is doing.