Cable in my area has switched to digital cable. I own a Hitachi HDTV about four years old. When I scan my channels it will only scan analog channels...the digital channels are an option but I don't know how to switch the scan to digital. Any ideas.

do you have the air option in the scan menu see
http://tv.manualsonline.com/manuals/mfg/sanyo/dp42841.html
page 9 important fact cable digital gets wiped by air digital channels

You may be able to get around this via a digital hd tv decoder box and then have it on a hdmi input on the TV as a backup to the cable if you can't have both cable digital channels stored and aerial digital channels stored

WHat brand of set is tis and the model #? Please post for me.

YOU HAVE TO CONNECT THE ANNTENA TO THE CABLE PART OF THE TV AND GO TO MENU AND SCAN SEARCH CHANNELS IT HAS TO SCAN THE CABLE SIGNAL FOR DIGITAL AND ANALOG SIGNAL IT MAY TAKE A FEW MINS YOU WILL HAVE TO DO THIS TO GET ALL THE CHANNELS

If you have a cable box then you don't do the switch in the tv, you do it in the box. If the box isn't a digital model then you must replace it.
BTW the digital channels operate on the same frequencies as the normal ones, to find them just do a channel scan.

Seeing as it does not have a digital tuner in it, I would think this would be the problem, you will have to get a box for it.

The channels for a digital stations are really just "names". Thy will be the number for the old analog channel followed by a "-" and a number 1 through 4. The actually frequency can vary
from the old frequency. You can see this at;
http://www.tvfool.com/

To set up your tv, you will have to connect your signal source (Antenna or Cable) to the set.
Go into the menu and select the Signal source (Channel) to match what you connected.
Go into the menu for scan or auto program and SCAN in the channels in your area.
Now you can watch the stations on your set.

If the broadcast frequency of any station change, you can re-scan it in again. The "name" will not change so the change will be invisible to you.

If you have tried autoprogramming and have found nothing it may be a bad tuner. Is your VCR is hooked up via coax or into a video input? If it is hooked up via video and is working but the coax connection direct isnt it will be a bad TV tuner. Easiest cheapest fix is to use you VCR to change channels or get a Digital Cable Terminal from you cable provider and hook it into video or compnent.

Ok first I can save you some money. Take your "HDTV" antenna back. There is nothing different about the antennas needed receive analog and digital signals. If you got reception without your converter box, use the same antenna with your converter box.

Next let's see if there is a problem with the box. Hook up a television with the antenna. How many stations do you get? Now hook up the same television & antenna, but this time put the converter box between the antenna & the TV. Do not turn on the box. Now how many stations do you get? If the number is different, the box is not allowing the antenna signal to pass through. That is bad. You want your signal to pass through the box so you can still pick up stations that don't broadcast digitally. Some areas of the country will not be covered by digital stations from all major broadcasters when the changeover happens in Feb.

My suspicion is either you did not have the antenna hooked up to the converter box when you searched for channels OR you are in an area that is not yet broadcasting digitally.

I hope this helps you solve your problem. Thank you for using FixYa and feel free to add more questions here by using comments.

you have to go into the menu and set for cable then scan for active stations.