[HandyAndyInNC]

You are correct about the insurance companies. But I do not see any knob and tube wiring. I see some old BX and maybe some cloth wrapped, but no knob and tube that I can see.

 

[Let it Snow]

It's obvious that your house needs some electrical work in cleaning up some of the code violations. I don't see any knob and tube in your photos. I would hire a licensed electrician that you can trust. BX cable (metal clad) is code compliant if it is terminated properly.

Changing the doorbell transformer is a simple project. Ring suggests a 16 volt, 30VA transformer like THIS.
It does not mount as some photos here show with exposed wires on the 120 Volt side. It mounts directly to a box or breaker panel with a 1/2" knock out like THIS.
It will mount directly to the side of the box. Then install a Blank cover.
The 120 Volt wires will be inside the box and the transformer will sit outside the box. Since the door bell wires are 16 volt, there is no need for a box if you splice those wires.
Before you install the box, find a new power source with newer wire, not knob & tube. The other option is to mount the transformer directly to the breaker panel. In that case you can splice the low voltage doorbell wire and run a new piece to the transformer.

 

[Let it Snow]

In THIS photo

the wrong box was used. It should be a metal box because one of the wires entering it is BX, the metal clad cable. I would change that box to a metal one similar to the link I posted. Buy a BX connector for the BX cable. Install a green ground screw in the metal box and attach the bare ground wire from the romex to it. Mount the transformer to that new metal box. Once you buy the transformer, you'll see how it mounts.

 

[Let it Snow]

The transformer would mount similar to THIS, of course it would have a blank cover on the box.

 

[Datawise]

So in my picture, which wires seem to be the 120v wires and which wires seem to be the wires going to the chime? A and B?

Also, there doesn't seem to be 3 wires for 120v, ground, and neutral. How would I hook up a modern transformer?

I know a couple of people had added already, but one last thing is the reasons why the transformer mounts to a metal box or panel. First as mentioned is the protection of the 120 volt wires. They must be protected from damage and people must be protected from potential shock hazard. The second reason is that by attaching the transformer to the metal box it acts as a "ground" to the transformer. The metal attachment screw or the locknut of the transformer make a connection to the metal box and that is your "ground" connection. You can see both example in the pic posted from @Let it Snow and myself.

Cheers
John

 

[Dkdndn]

Hey y'all-- thanks for all the pointers. I went to home Depot today and picked up all the things. Yes-- I know I definitely need to get a lot of the wiring updated (working on it-- in the process of making renovations to this century-old house). For the time being, I just want to get this doorbell working! And I did! Attached is what I ended up doing; on the left is the ancient transformer and on the right is my new 16v transformer. I just took the old cables, taped them up a bit, and hooked them up inside the box. I did also make sure I took the green grounding wire from the new transformer and grounded it to the box with a green screw.

Thanks again everyone!

 

[Nealtw]

Hey y'all-- thanks for all the pointers. I went to home Depot today and picked up all the things. Yes-- I know I definitely need to get a lot of the wiring updated (working on it-- in the process of making renovations to this century-old house). For the time being, I just want to get this doorbell working! And I did! Attached is what I ended up doing; on the left is the ancient transformer and on the right is my new 16v transformer. I just took the old cables, taped them up a bit, and hooked them up inside the box. I did also make sure I took the green grounding wire from the new transformer and grounded it to the box with a green screw.

Thanks again everyone!

Except you should have and still can pick up a length of 14/2 cable and change out that 120 volt wire and wire it in the other box too. :wink2:

 

[Dkdndn]

@Nealtw I've added it to my todo list! This doorbell project was a tangent. I still have kitchen and bathroom renovations I need to finish up *sigh*

 

[de-nagorg]

If that box is not grounded to earth, your ground connection is not any good.

You need to add a ground wire to the nearest metal plumbing, or the ground for the house wiring.


ED

 

[jimn]

Based on this I think you are going to find lots more electrical supervises in this house. . The simple way to make this more safe is simply to mount a 4 inch junction box at this location. Use an armored cable retraining clamp and feed the armored cable into it. You can often find a cover plated with a hole punched in the center. It the big box store doesn’t have one an electrical supply house will. Buy a new transformer which you mount to the cover plate and the 120 V wires will go through the hole in the plate . Secure with the included nut and using new wire nuts connect the 120 replace the cover. If you can’t find a cover with a hole, puch about her side knock out and mount it there. The transformer will be on the outside of the junction box. Screw the low voltage wires onto the new transformer. Caveat, depending on the condition of the armored cable , this box may or not be grounded. To be modern day code complaint it would need to be connected with 3 wire armored or NM cable (hot, neutral and ground).