Problem with any over the air antenna and a new 50" DU6900D 4K TV

[Figureguy]

Good afternoon.  My stepfather doesn't have cable but has internet.  He has an over the air antenna that he had attached to a 43" VIzio that is about 7 years old.  When he would use it on that television it would give him about 40 channels.

We talked about this unit being on sale and the Samsung TV Plus with his internet giving him over 400 channels for free.  So he bought the television and I had the television scan for channels.  It picked up all the Samsung TV Plus Channels fine but only 13 local over the air, much less than the got with the older tv with the antenna.

I hooked up the antenna via the coaxial cable portand then rescanned for channels.  The TV still only picked up the 13 local and not the 40 he is used to.  He does have an older antenna and I was looking for newer ones online but if it was able to find 40 channels with an older TV I am confused why the newer TV is not using it to find those missing channels.

Thank you in advance for any help you can give me with this.  I tried calling Samsung but the gentleman kept saying it was due to various factors, and he wasn't understanding I hooked the antenna to the new television.

[realaud]

Have you changed the location of the TV set or the antenna from where the old set was located?  Ideally the antenna (and it should be a digital antenna), should be placed a close to a window or have a clear sight line to a window with no walls in between, or placed near an outside wall so there is no signal interference. Antennas do not have to be situated near the set, so you can get a longer cable to move it as close to the outside as possible.

[Figureguy]

Thank you for responding.  No the TV is on the same stand as the older one and the antenna is still sitting where it had always been.  I'm not sure as if it is a digital antenna.  It is basically this:

He got it about 6 years ago.  It is not that exact model but similar in design and function.  I am actually looking to get something like this:

I would think it might work better than the current one but he put the older antenna back on the Vizio and got his channels as normal.  I understand a newer antenna would be better overall but why is it needed to get what he normally could with an old antenna and an old TV?  Why is he losing channels?

[Figureguy]

I had a thought. I don't know if the old TV was a smart TV and I don't know if it had digital scanning capabilities. It's at his house and I'm at mine and I don't think he would know enough if I asked him to be able to tell me. If the new Samsung is using the internal Channel Scanning ability to find over the air could it not even be using or even recognizing the antenna despite it being plugged in? I know I went to Broadcasting and chose all so we pick up channels and that's how I got the Samsung TV plus and the 13 local. Is there something I'm supposed to do to specifically have the TV use the antenna? I'm not sure myself as I've never used any kind of setup like this. I've been looking on the internet and it talked about source being changed to TV and scanning but I don't see that capability on his as it doesn't say there's anything hooked up via another source.

[realaud]

The old TV may have had a tuner built in, the newer TVs most likely do not, as to keep the costs down to encourage more people to buy them.  If it's 6 years old the antenna is most likely digital.  The TV most likely is recognizing the antenna but, because there is no internal tuner, it's just not picking up the signals.  I would probably go with something like this, as you can move it around better than the one you show, so you can put it in an optimal location.

https://www.amazon.com/Digital-Antenna-Magnetic-Reception-Channels/dp/B0C6M6K4WT/ref=sr_1_28?crid=OI...