Eric Oshlo Says:
January 14th, 2007 at 10:47 am e
Your blog on connecting multiple DirecTv receivers is great; however, I offer one comment and have one question.
First the comment: I think the section on connecting an OTA is obsolete if you have a system that receives HD local channels from DirecTv (HD20 receivers, etc.) I was forced to replace my multiswitch when I went to HD locals from DirecTv because my Spaun switch would not pass the HD local sat signals. The new Zinwell switch does not have an OTA input, apparently because the new signals reside in the same frequency band as typical OTA broadcast signals and would create a conflict.
Now the question: what is the best approach if I need more than 8 output signals from a multiswitch, all HD capable? I havenâ€™t seen a switch thatâ€™s DirecTV HD Locals capable with more than 8 outputs. Can you point me to one? If not, can two Zinwell switches be run in parallel by using DC power passing splitters on the four incoming cables from the dish and being careful to run the split signals to the matching inputs on the two switches? I only need a couple of additional outputs.
I know there must be a way to accomplish this for use in larger installations such as apartment buildings, etc.
You are correct about the new dish not being compatable with the OTA of the earlier designs and I should update that article to cover that. It was written before the AT9 was available and my oversight for not updating it.
As for it being obsolete, not necessarily. Until all of the HD equipment is changed over to the new system, it is still viable. Many customers have elected to stay with the 3LNB dish because of the fact that all of the DTV local stations are not yet on the dish. Here in Houston it was a long time before our CBS affiliate was available on the new dish. As it is now there are 4 out of some 28 digital channels available here in the Houston area with the PBS digital channels being the most obvious ones missing. If all of the stations were comming in with their OTA antennas, people didn’t see the need of changing.
Now to your question. Yes you can use DC passing 2 ghz splitters to connect 2 Zinwell 8 port multiswitches to give you 16 outputs.
As far as the OTA is concerned, it is true that the new LNBs have local oscilators that put the IF out of them in the 250MHz - 750MHz band which conflicts with the OTA signals. But what is not widely known is the B band converter that attaches to the back of your H20 (or equlivalent) converts this band back up to the 1650Mhz - 2150MHz range. Therefore it is possible to relocate the B band converter to the dish side of the multiswitch and send the 1650Mhz - 2150MHz through the coax. This frees up the OTA range. The reason Directv chose to down convert the signals to the 250MHz - 750MHz band is the 1650Mhz - 2150MHz band is at the upper end of the limits of RG6 coax and if the coax is old and/or poorly installed, RG6 could have a much lower bandwidth than 2150Mhz. Rather than take the chance of having to replace coax (that would have angered a lot of installers) they chose to eliminate the OTA possibility. Makes sense from their prospective since they were supplying a system that in their mind would eliminate the need for OTA antennas. And for many, if not most, people that was a good assumption.
If you are interested in this approach, I would say do some google searching and find out the particulars. I know the B band converter relocation has been done, but I have no first hand knowledge of the particulars. Also if your coax is not in great shape, I wouldn’t bother. If you are going to run new coax, run it for OTA.