I have had my media center set up for roughly a year with two ati digital cable card tuners and two dual tuner combo cards.  Each dual tuner card has an analog tuner and a qam tuner.  This brings my ability to record separate channels up to 6.  I can record two high definition cable channels, two analog channels, and two qam recordings at the same time.  I have comcast in the chicago suburbs.  Recently they sent me notification that any television in my house that was not connected to either a cable box or a tuning adapter, that when they make the switch to all digital this spring, would not work properly.  I fully understand the purpose of a tuning adapter and what sdv means.  The two free tuning adapters that they have sent to me are for standard television hookups and do not have usb capabilities.

 My questions are as follows.

 I was under the impression that with my ati digital cable card tuners I would not need a tuning adapter, however this article shows just that.  A usb tuning adapter for sdv connected to an ati cable card tuner.

http://usingwindowshomeserver.com/2009/11/21/installing-a-tuning-adapter-in-windows-media-center-on-a-friday-night/

Am I going to need to install a tuning adapter for each of my cable card tuners when comcast makes the switch to all digital in a couple months?

Furthermore, in regards to my two analog tuners.  Would I be hooking up standard tuning adapters (like the two free tuning adapters comcast has already sent me for standard televisions)  to these two analog tuners and using an ir blaster to change the channel on them, or would I use something more like the adapter suggested for the cable card tuners in the above link?  A usb tuning adapter like the Cisco STA1520 as mentioned in the above link.

Thanks for any clarification and help you can provide guys.  If I was unclear in my descriptions, just ask a question, thanks.

-Ryan

 UPDATE*

 Just for the hell of it, I just did an online chat with a comcast rep and asked him about usb tuning adapters for my ati dct's   He told me that I would not need a tuning adapter for my dcts even though they are in fact switching to sdv.  I am unsure if he is correct as he very well may not have a clue as to what a digital cable tuner is.  Then I proceeded to ask him if comcast offers support similar to that of the Cisco STA1520 for my two analog tuners in my media center pc, and he replied with that they simply support cable boxes and tivo's with cable cards.  I didn't feel he answered my question and was perhaps in over his head.

 From reading what I can on comcast's site, is it possible that their switch to all-digital is not the same as sdv?  Is this possible?

 thanks for the reply jmallory.  I wasn't aware that a switch to all-digital was something different than sdv.  I guess comcast is banking on not having to carry both standard and digital service to free up bandwidth where as sdv frees up bandwidth by only having to send one channel at a time.  I was under the assumption that going "all digital" was the equivalent to sdv. 

 So this seems to me that in order for me to continue having my two analog tuners working on my media center, I will in fact have to use comcast's "digital transport adapter" as they call it (which I assume is slightly different than an sdv tuning adapter) and use an ir blaster to change the channel.

 Am I getting this right?

 well it appears comcast is deploying sdv in at least some of it's markets.

http://www.slashgear.com/first-sdv-tuning-adapter-is-out-to-comcast-subscribers-0718546/

 Are we sure this all-digital switch I am about to experience isn't sdv?

mrfrankmrfrank

 Are we sure this all-digital switch I am about to experience isn't sdv?

There are a handful of markets where Comcast has deployed SDV (mostly markets where they were another company they acquired recently) but in general, Comcast is not using SDV.  From the wording of the letter you quoted (the part about TV's not working without an analog box) it doesn't sound like you need to worry about SDV. 

I'm pretty sure you are confusing DTAs (which are basically the brain-dead cable boxes they provide for free when they shut off analog) and Tuning Adapters.

 Yea, I guess I was confusing dta's with tuning adapters.  I thought they were the same thing.  Looks like I'll have to get some spare dta's and hook them up to  my analog tuners with some ir blasters.