If you have a single coax line to each room in your house and DirecTV (or just about any other DBS satellite service) you may already be familiar with the fact that you can’t simply split satellite signals like you can with cable TV. Because the satellite companies use antenna (transponder) polarization to put twice as many channels on the same frequency range and they use a 22 kHz signal from the receiver to indicate which polarization should get sent down the line a regualr splitter causes problems. The solution is called a multiswitch which uses a dual-LNB satellite feed to fix one LNB to each polarization and then offer either feed to the receiver that asks for it. This is all well and good if you only have an single receiver in each room.

The problem comes when you have more than one tuner per room such as with a dual tuner TiVo system. You either need a seperate run back to the multiswitch for each tuner, or if you have more than two can use two runs and a cascading multiswitch to split the signal again. What about people who only have one run to a room and no way of adding another one without major construction? Thankfully a company called Sonora has come up with devices called Stackers and DStackers which can combine two polarizations and then split them back out again. The downside is you need both a Stacker and a DStacker which adds up to around $300 worth of additional equipment.

Personally, I think the satellite companies could think a little more creatively about this and offer a centralized tuning system with multiple modular tuners and then send only the channels you want over the coax to a receiver in the room which demodulates it and sends IR commands back to the centralized tuner system. This would also facilitate sharing the TiVo functionality to multiple rooms and lots of other cool ideas. Then again, I’m not all that impressed by the DBS satellite companies anyway, are they really any better than cable? I don’t think so.

In addition to some of the other free e-book resources I’ve mentioned in the past is this latest addition. It seems that renowned computer book publisher, O’Reilly has put some of their out of print books and some books that have been written under open licenses up on their “Open Books” website for free download.

I wish that more publishers would do this. It really makes sense, especially with older books. Once a book (or a paper or conference proceedings for the more academic among us) goes out of print it can become quite difficult to get ahold of a copy. If I were a publisher I would make my catalog available for free on the internet but provide links for people to purchase print copies (even of out-of print titles, doable with new short-run printing technology). After all, if it’s really a useful or interesting book most people still want a paper copy, in effect you’re letting the book sell itself. Of course if the book is junk you won’t sell very many copies but I don’t especially have a problem with that.