D-12 vs. HR-21 Signal Issues

**snipermatt** · 07-17-2008 01:28 AM

Hello All, first time poster here. I don't know how deep I can get here technically but I have a serious issue with my signal that nobody can seem to figure out. I switched from cable to DirecTV and loved it. I live in a very large apartment building in San Francisco (43 stories, 486 units) which is served by a company called "Consolidated Smart Systems" for Sat TV. We have a dish array on the roof and the signal is split out to from there to the individual units at "J Boxes" which serve a few floors of the building each. High speed internet (via a local telecom) is piggy-backed on a single coax line into my unit and split out to my cable modem and sat box (HR-21, HD+DVR). Even with one coax input to the sat box, I can still record on two tuners. My problem is that one random day, my box stopped receiving a signal. After a couple technician visits, including the guy who designed the building's massive sat TV switching/routing system, the only clue anyone has is that the internet signal (which is piggy-backed on the same line) seems to be running too "hot" to my unit. The strange thing is that while the HR-21 is not even capable of receiving a signal, the loaner D-12 box (basic model, non-HD, no DVR) fires right up with no problems at all. Obviously there is an issue with signal quality (even tried using the BBC which wasn't required and still does nothing) but my question is, how do these two boxes process the signal differently (above and beyond the functional aspects i.e. HD and DVR)? How come the HR-21 can't get past 0% in the initial signal acquisition and the D-12 sucks it down like a cold beer on a hot day? They even gave me a brand spanking new HR-21 and it still can't acquire a signal. Any ideas? PLEASE don't make me go back to cable...if I have to stare at that weak blue comcast menu again, I might puke.

**texasbrit** · 07-17-2008 10:45 AM

You are using an MDU system (multidwelling unit) system, from your description it seems like it is using the new MFH2 system which is based around the SWM8 single-wire multiswitch.
It's difficult to know from your description what the problem might be. Most of the MDU techs are still not very aware of how the system really works. One possibility is that someone has installed extra receivers/DVRs somewhere in an apartment that is on the same SWM8 as your apartment. Each SWM8 will support eight tuners in total. Each DVR is two tuners. It is possible that there are seven tuners, other than yours, on the SWM8. That means you can add a D12 without any problems. But the HR21, being two tuners (only one cable but still two tuners) is putting the tuner count to 9 and of course that will not work correctly.
Maybe the tech is just counting connections instead of tuners, and is only counting any of the DVRs on the system as one instead of two tuners. Or maybe someone in one of the other apartments has added some tuners without the tech knowing about it. That's one of the problems with MFH2, someone in one apartment can screw up the system for others without realizing it.

**snipermatt** · 07-17-2008 11:11 AM

Let's say the "7 of 8 tuners" situation is the case - the HR21 wouldn't even recognize one tuner? During the setup process, it's showing zero tuners and not acquiring any signal whatsoever.

You're right though - this is not a simple question with an obvious answer considering the sheer scale of the system here...especially with me not having any access to (or knowledge of) the system beyond my wall coax jack. That said, any other ideas/suggestions are much appreciated!

You would think the system integrators and/or technicians would be the ones looking up potential solutions on the internet instead of the customer, but I digress. At least I got a free month of service after escalating this...even though all I want is my frickin TV to work and go on with my life.

**atp1313** · 07-18-2008 12:54 AM

snipermatt - So based on some basic math, and the explanation from texasbrit, it sounds like you have about 10-11 units per floor in this building, and each floor (or several floors at a time) is getting its own unique feed, it sounds like the SWM8 would get overworked pretty quick.

Texasbrit - Can the SWM8 be piggybacked or split in series so that one split can become two or four or eight SWM8's and therefore supply enough signal for each apartment unit assuming each apartment has at least 1 HDDVR? Is it a voltage issue or bandwidth issue that causes the overload and resultant inability to add more receivers/tuners? Could snipermatt's proximity to the SWM8 be an issue?

**Cuong** · 08-05-2008 06:00 PM

SWMs can't be in piggybacked.
If you're within 200ft of the SWM, signal is not a problem if cable was installed properly.

snipermatt - Did you do a force download on the HR-21 to get the lastest software?

**texasbrit** · 08-05-2008 06:28 PM

Originally Posted by atp1313

snipermatt - So based on some basic math, and the explanation from texasbrit, it sounds like you have about 10-11 units per floor in this building, and each floor (or several floors at a time) is getting its own unique feed, it sounds like the SWM8 would get overworked pretty quick.

Texasbrit - Can the SWM8 be piggybacked or split in series so that one split can become two or four or eight SWM8's and therefore supply enough signal for each apartment unit assuming each apartment has at least 1 HDDVR? Is it a voltage issue or bandwidth issue that causes the overload and resultant inability to add more receivers/tuners? Could snipermatt's proximity to the SWM8 be an issue?

You can split the signals on the four cables from the dish to drive multiple SWMs in parallel. The limitation of the SWM in driving tuners is a basic design parameter, nothing to do with voltage or signal strength. The SWM8 creates nine channels on the single cable, one channel is used to communicate shared data like the guide, the other eight carry the transponders selected by the eight tuners. That's why eight is the limit for each SWM..