I know there have been a fair amount of helpful postings over the years by people who have figured out how to work around the channel limitations of the AM21 OTA tuner. I've seen some other postings on DBStalk that explain how to get missing subchannels in markets such as Chicago and Los Angeles. So, I thought I would create my own for anyone who is interested in getting all the channels in the Washington-Baltimore region. For those who don't know: DirecTV DVRs and receivers will get OTA channels if the AM21 tuner is attached via USB cable. But where it gets tricky is when it comes to adding the channels to the program guide. DirecTV's system is not typical when it comes to adding channels . . . a typical OTA tuner on a TV, for instance, will simply do a channel scan and add whatever channels it finds. DirecTV doesn't do it that way. Instead, you put your primary and secondary zip codes of your area into your antenna settings on your DVR or receiver, and the box will "phone home" to get the list of OTA channels that DirecTV has deigned to allow you to tune. When I did the initial setup on my AM21/HR24-500, the program guide showed 41 channels for my primary (21045) and secondary (20884) zip codes. But a separate, independent scan I did on my Bravia television's tuner showed that I get 58 OTA channels, meaning DirecTV's program guide was not allowing me to tune in 17 channels that my antenna receives. So here is what I did in order to get those extra 17 channels: 1. I found zip codes in different areas that would enable me to get those missing subchannels. For instance, two of the subchannels DirecTV was not giving me were 7.4 and 13.2. I particularly wanted 13.2, because that is the CBS' "Decades" channel that runs lots of fun old campy TV shows like Hawaii Five-O, Mannix and Green Acres. So, I consulted this handy list that shows every digital channel number for hundreds of zip codes across the U.S.: Antennas Direct | List of Digital TV Stations 2. I did a new initial setup for zip codes 32401 (Panama City, Fla.), which gets channels 7.4 and 13.2, and for Milwaukee, Wis. (53201), which pulls in two other subchannels I was missing: 20.4 and 45.3. DirecTV found the channels and added them to my D* program guide. More importantly . . . Once they are on the channel guide, it means I can tune in the channels on my DVR and use its capability for all those good things like pause, rewind and fast-forward. But due to the discrepancy in channel programming in the Panama City and Milwaukee markets, the shows listed on the program guide are incorrect. But that's a price I can live with in order to get the channels. 3. I did another initial setup (you can run as many setups as you want, because your previous setups are saved) for Albuquerque, N.M. (87101). This got me subchannels 5.2, 5.3, 20.2, 20.3, 23.1, 23.2, and 32.2 (nice bang for the buck on this one.) For the secondary zip, I put in Santa Ana, Calif. (92701), which got me subchannels 2.4, 22.4, and 54.4. 4. One final initial setup, this one for Marietta, Ga. (30008), which got me subchannels 14.2, 14.3 and 14.4. Done! The DirecTV program guide now gets all 58 OTA channels that my attic antenna receives. You'll find some duplicates in the program guide - for instance, channel 13.1 was listed twice after I did the Panama City setup - but this is easily filtered out by making a custom favorites channel list on the HR24. The biggest downside of this, of course, is that the program guide will not show the correct listings for the 17 channels I added. But getting the channels is the bigger issue to me, and I can always look up program guide data for my local area on my phone if I really need to see what is on my newly-added channels. Hope this helps someone.