Yes, the A1470 is the "tall" Time Capsule, the latest model that is still being sold. I have one too!
If I connect the TC directly to my imac via ethernet cable can I use the TC as a hard drive?
The simple answer to this is "no". However, if you connect the TC directly to your Cisco DPC3848V, you can easily use it from your iMac as a network-connected hard drive. You can put whatever you want onto it. Copying large files to the TC drive would be somewhat slower than copying them to an external hard drive connected to your iMac, but usually wouldn't be a problem. I'm not aware of a way to access it from your iPhone or iPad, but I wouldn't be surprised if there was some way to do that. It's important to know, though, that file that you "manually" put onto the TC disk will
NOT be backed up anywhere (by default). So if you can't afford to lose them, you must keep copies somewhere else.
That brings up the important topic of backups of your iMac. Its storage device (whether hard disk drive, solid-state storage, or "Fusion Drive") could fail, and if you have "important" files on there that aren't stored somewhere else, you could lose them forever... right? So, are you backing up the important files on your iMac somehow? How do you back up your iPhone and iPad -- backup to iCloud, or backup in iTunes on your iMac?
If you're not backing up your iMac, I highly recommend that you use the TC for this. (You can still put other files on its disk, too.)
If you just want to use the TC disk space, use a regular Ethernet cable. One end into one of the three TC LAN ports, and the other end into your Cisco DPC3848V, any one of the four LAN ports on it. Power it on. Then open Airport Utility on your Mac. It's in the Utilities folder which is inside the Applications folder. I think once you open Airport Utility it will "find" your TC and let you set it up.
I can't remember if there's a "wizard" for the first setup. If not, try the following: Click on the TC in the window, and click Edit. The most important setting is to go to the Network tab, and for Router Mode, pick "Off (Bridge Mode)" from the list.
On the Wireless tap, you can turn off its WiFi radio by picking Network Mode: "Off". Internet tab will probably default Connect Using: to "DHCP", which is what you'd want for this setup. Then go to Disks tab, where you decide what password will be needed for your iMac to access the TC disk. Other settings probably are fine, but you can go ahead and look at them.
After updating the settings on the TC, open Finder on your iMac. The TC will probably show in the Finder's sidebar with whatever name you gave it. If not, go to Finder's settings and ensure that "Connected Servers" is checked on the Sidebar tab. (Or maybe it's Bonjour computers, but I think connected servers.) Then it should show up. When you click it in the sidebar it should ask for the disk password (which you can store in your keychain so you won't have to enter it again.) Then you can access the TC disk space right there in Finder.
Hope this is not too confusing, and is helpful.
But again -- think about your iMac backups. If you don't have Time Machine set up for your iMac, you can do it now by going to System Preferences-->Time Machine-->Select Disk and your TC disk should show up in the list.
Good luck!
[doublepost=1478644319][/doublepost]Oh, forgot to mention. I found a spec sheet for your Cisco DPC3848V router/WiFI access point. If it's all set up and working, and you don't want to fiddle with it, I see no need to. Its WiFi should be just as fast as your TC's would be. And with your small area I doubt you'd get any benefit from another WiFi access point.
One last idea for you TC is to sell it. If you don't need it as a router, WiFi access point, backup destination, or disk space... surely someone else would -- especially since it's still the latest model. Don't know what the going prices are for used ones, though.
