Ed,
Forgive the size of the post, but the suggestions below have helped others with similar issues. Try each topic individually and see if things improve, If not move on to the next one.
*Keep the Time Capsule Cool*
Some posters have observed that when they positioned the Time Capsule for better ventilation and cooling, their network connectivity issues resolved themselves. Also avoid locating the devise within poorly ventilated cabinets or piling items around or on top of it.
*Time Capsule Orientation*
While the location you chose to setup your Time Capsule may be acceptable, but the direction it is oriented can have an effect on signal strength. It appears that the signal of the Time Capsule does not radiate equally from all sides of the devise.
The antennas within the devise are positioned along the 3 smooth sides. That is, there is no antenna on the side bearing the ports and cables. As a result, position the devise with the ports and cables AWAY from the direction of most of the clients that will be connecting to it.
*Cordless Phones*
Some users have discovered that the cordless phones they have in the home occupy or are near the same bandwidth as their wireless network (2.4Ghz or 5Ghz). Try temporarily disabling the handsets and their bases and see if network connectivity improves. If so you may need to change the channel that the phone uses or purchase phones that occupy a different bandwidth.
*Preferred Networks & Airport Services*
You may be experiencing interference from other networks in your neighborhood. When you click the Airport menu are there other networks listed other than your own?
If so, is your network at the top of the list? It should be.
Go to System Preferences --> Network --> Select Airport on the left.
Click "Advanced". In the “Airport” tab note the various local wireless networks that Airport detects. Is the network you prefer to connect to at the top of the list? If not drag it to the top. Are there other networks you never intend to connect to (an old work network, or a neighbors network)? Then highlight them and click the "-" button.
Make sure “Remember any network this computer has joined” is checked.
Click "OK".
For "Network Name" be sure your network is selected and then click "Apply".
Is Airport (wireless) your primary means of connecting to your network? If so, is Airport at the top of the list of services on the left? It should be.
Click the small “Gear” button at the bottom of the window and select “Set Service Order”.
Now drag Airport to the top of the list.
Click “OK”. Click “Apply”.
Now see if network connectivity has improved.
*Transmit Power & Wide Channels*
If you are using the 802.11n only (5GHz) radio mode, you can also select to use wide channels, which provide higher data throughput in your network.
Launch Airport Utility
Select your Time Capsule on the left.
Click “Manual Setup”.
Select “Airport” in the toolbar.
Click the “Wireless” tab.
Click “Wireless Options...” at the bottom of the window.
Adjust the “Transmit Power” to 100%.
Put a check mark in the box labeled “Use Wide Channels”. (If you are using a 802.11a/b/g (2.4GHz) radio mode then select “Interference Robustness”)
Click “Done”.
Click “Update” in the lower right hand corner.
Wait for the Time Capsule to restart and then see if your network speeds improve.
*Reduce the DHCP Lease Time*
Some have found that reducing the DHCP lease time improves their network connectivity.
Launch Airport Utility
Select your Time Capsule on the left.
Click “Manual Setup”.
Click “Internet” at the top of the window.
Select the “DHCP” tab.
Change “DHCP Lease” to a shorter time.
Click “Update” in the lower right hand corner.
Wait for the Time Capsule to restart and then see if your network improves.
Let us know if any of these suggestions improve your situation.
