Weak wifi signal/signal loss

Stupid Question, what is RG?  The modem and router are in the main floor in the corner by the TV.  The signal is weaker upstairs and on the other side of the house (stairs in between) and about 25 feet away.  The house is two stories with a basement.  I was thinking of moving it upstairs into a room without a TV (would that work?). 

Ok, I have a few questions.

Right now the cable and the phone line from the wall are in the RG and then ethernet to the cable box.  If I want to move the modem/router to another room without a tv do I just plug the cable into the cable box for the TV, and then the phone line into the modem in the other room?

After I figure that out, I bought an Apple Time Capsule today that I'd like to use as my router so I'll need to figure out how to set that up.

Yes, we do have voice.  I'll have to see what jack in the RG has the phone line.  We have another TV connected to coax and then one more with the wireless STB.  I don't necessarily need to move the modem, but I've read that being next to the TV could affect the signal (and maybe I should move it upstairs anyway).

Thanks.  That seems like a lot of work since I'm not sure if the upstairs coax was updated/changed when we switched to U-Verse.

I may try an extender via ethernet, or I may just try the Apple Time Capsule to see if that helps.

Would something like this work for better wifi throughout the house?

http://www.amazon.com/Linksys-Powerline-Wireless-Extender-PLWK400/dp/B0087O6AQE/ref=cm_cr_pr_product_top

In my younger days, I was an early adopter and had a bad experience with powerline adapters, supposedly because of my GFI's.  I don't know if that was the problem or it was "version 1 syndrome".  In any case, my wireless problem was solved with a TP-Link Wireless Access Point:

http://www.amazon.com/gp/product/B003CFAU0A/ref=oh_details_o09_s00_i01?ie=UTF8&psc=1

It's cheaper ($46) than the powerline adapter, and I've have really good luck with it.  I say luck because wireless these days seems to require a certain amount of luck.  I just turned off wireless in the RG and connected the WAP to one of the Ethernet ports.  Another thing you can try (or use in addition to other solutions) is inSSider, a freeware product for surveying your area for wireless networks.  With that you can find a channel that is free of competing wireless networks.  Here's a link: http://www.metageek.net/products/inssider/

With the TP-Link WAP upstairs in the front bedroom set on a clear channel, I get "Excellent" signal strength on my kitchen Roku downstairs in back of the house, and my iPad works well everywhere on my little city lot.

I had this issue too ... purchased a D-Link DLDAP1320 DAP-1320 Wireless Range Extender ... was an easy install and works like a charm ...

Cost ~$40 & one of the things I like about it is that I can unplug it & move it around the house as needed ... for example when I want to be on my screened porch I place it b/w the gateway and the porch and when I want to be in my backyard I place it in my basement and you don't have to re-install it everytime you move it around. It just reboots and re-syncs with the gateway.