In fact, you can buy a signal booster on Amazon or in any physical store . This will allow you to improve reception of most TV channels and never have any problems. An amplifier allows you to increase the power of the signal coming from the antenna.
However, building a DIY antenna —if only to improve the signal— is not an illegal move . Building a small antenna like the one we just saw won’t cause you any problems, but we don’t recommend it for safety reasons .
You have to be very handy in the field of electronics to build a DIY antenna that can really provide a useful solution for signal improvement.
