Reddit mentions of C2G 27312 RCA Female to F-Type Male Video Adapter, TAA Compliant

Can use bare wire, but it's not the most secure/safe connection. Get open screw banana plugs and connect them with the port and your speaker wire (like so), can also be used on the receiver side. If you don't have a receiver, that's obviously where you need to start.

Is it just those two or are there others? If not, then it's just stereo.

(*See discussion below) The blue port is for a subwoofer, instead of RCA it uses a standard F-type coax cable (like for tv), so you need an F-type male to RCA female adaptor on the receiver end and the reverse wherever the subwoofer is/will go (unless there is an in-wall subwoofer already installed), as seen on the Amazon page, just buy the "Frequently Bought Together" bundle, you'd also need a female to male subwoofer cable.

The threaded connector is called a F connector; this should help with searching.

Here is an example

You need one of these.

https://www.amazon.com/C2G-Cables-Go-27312-Compliant/dp/B0002J25OI/ref=sr_1_5?ie=UTF8&qid=1524185848&sr=8-5&keywords=rca+to+coaxial+adapter

Screw this into your antenna in, plug the atari's rca-ish plug into the adapter, and tune the tv to the broadcast channel you have selected on the unit. Power it up, and there you go.

Probably, yes. These are very common cables/adapters.

Here's some links:

6ft RCA cable on Monoprice

RCA female to F-type Male adapter on Amazon

You can really use a bunch of different types of cables and adapters, this is just what I would try to find.

Looks like a 3.5mm connector on the back of the TV, does the plug on normal headphones fit it?

If so, you'll need a way to get from F connector to 3.5mm, F to RCA adapter https://www.amazon.com/C2G-Cables-Go-27312-Compliant/dp/B0002J25OI/ref=sr_1_4?ie=UTF8&qid=1523683160&sr=8-4&keywords=f+rca + RCA to mono 3.5mm should work https://www.amazon.com/iGreely-3-5mm-Audio-Cable-Plated/dp/B01LW6C4DA/ref=sr_1_3?ie=UTF8&qid=1523683148&sr=8-3&keywords=3.5mm+rca+mono

The easiest way I've found is to use a coaxial input and one of these micro-adapters:

https://www.amazon.com/C2G-Cables-Go-27312-Adapter/dp/B0002J25OI/ref=pd_sim_23_4?ie=UTF8&psc=1&refRID=RH7CJN5TWCVEBA6GW1WP

They seem to work better than the old switchboxes or trying to get a component modulator to work or whatever else.

It sounds like there might be a short in your RF switch. If the RF out is working properly on your NES, all you need is something like this (and an RCA cable).

Edit: you can downvote all you want, but if the RF switch works when it's held at certain angles, that's a pretty clear sign that there may be a short in the cable. If you have a more helpful suggestion, REPLY... your downvote helps nobody