Q: How to add tv to new wifi network w time capsule?

Is the panasonic using wireless?

What was it using before the TC?

Sometimes it is easier to actually keep using the old router for AP mode.. so products that are not Apple have something to connect to.

Certainly you can improve matters by making your TC more SMB networking .. ie most of the rest of the world but Apple.

Make sure all names are SMB type.. that means short.. 2-20 characters. No spaces and pure alphanumeric.

Use WPA2 Personal with 10-20 character password. Pure alphanumeric.

But if the TV is older then you may need to use WPA+WPA2 which is not as good.

Try without any security briefly to see if security is the problem.

Finally try fixed wireless channels as that can also help.

11, 6, 1 for 2.4ghz are the only channels that do not overlap.

I doubt the TV will have 5ghz.