Contact the television service provider to find out what kind of service you can expect using the equipment your purchased.
You didn't say which Slingbox you have, but there's only one Slingbox that has hybrid analog and digital tuner; the Slingbox Pro-HD. If you have any other Slingbox with a coax input, it only supports analog signals. This is important because not all service providers broadcast compatible channels on their line. The Slingbox Pro-HD's tuner will accept over the air ATSC or unencrypted QAM signals, where as the older Slingboxes can only pick up analog channels.