HeteroSapiens
July 11th, 2004, 12:51 PM
I've already solved my problem, but wanted to share my experience for the benefit of anyone who has a similar one. First, for context, let me describe my system: I have four receivers connected to a dual LNB dish via a 2x4 multiswitch. The system had been working perfectly since Dec 2002, when I added the multiswitch and two receivers to my existing (~1999) two receiver setup.
Like many others who have posted here, I found that I could get signals only from even-numbered transponders. After searching at length through the forum, I found that this can be caused by failure to get 13 volts to one of the LNBs. As noted elsewhere in the forum, this can be due to bad cables (95% of the time according to one contributor), bad LNB (4%) and/or bad receiver (also known as an IRD) (1%).
I started with the cables. I didn't expect to find a problem here, since I used weatherproof cables with silicone grease and sealed each outside connector, but 95% is 95%. As I inspected each connector I found it to be bright & shiny, with no sign of water, debris or corrosion. No problem here.
Next I checked the voltage coming from each receiver (measured between the inner cable and the outside of the connector). When tuned to a channel on an odd numbered transponder (see http://forums.digitalinsurrection.com/forum/showthread.php?t=155280 for a mapping of channels to transponder numbers) you should measure about 13 VDC. When tuned to a channel on an even numbered transponder ou should measure about 18 VDC. In my case I found that three receivers output the expected voltages, while the fourth output 10.83 VDC regardless of what channel it was tuned to.
At this point, I thought I'd found my problem. I reconnected the three good receivers to the multiswitch and went inside to check it out. Surprisingly, I still got only even transponders!
Next I tuned one receiver to channel 271 (odd transponder) and one to 278 (even transponder) and hung a test cable on each LNB connector on the multiswitch. I found that both were outputting 18 VDC (should have been 18 VDC on one cable and 13 VDC on the other). Found the problem - bad multiswitch.
To be certain, I connected two receivers directly to the LNB cables coming from the dish with a cable extender fitting and tested both receivers. I found that both got strong signals on all transponders, thus verifying my diagnosis.
So I ended up needing a new multiswitch (~$60) and a new receiver ($49 from DirecTV with a 1 year commitment). Since I'd been lusting for a DVR for the last few months, I opted to go for that ($99 from DirecTV, including professional installation). Since I insisted on getting the two-cable connection, this required replacement of my multiswitch (a freebie with professional installation, since (from DirecTV's point of view) my 4 output multiswitch was fully used by my four existing receivers).
Hope this helps somebody as much as the other postings helped me to find my problem.
Like many others who have posted here, I found that I could get signals only from even-numbered transponders. After searching at length through the forum, I found that this can be caused by failure to get 13 volts to one of the LNBs. As noted elsewhere in the forum, this can be due to bad cables (95% of the time according to one contributor), bad LNB (4%) and/or bad receiver (also known as an IRD) (1%).
I started with the cables. I didn't expect to find a problem here, since I used weatherproof cables with silicone grease and sealed each outside connector, but 95% is 95%. As I inspected each connector I found it to be bright & shiny, with no sign of water, debris or corrosion. No problem here.
Next I checked the voltage coming from each receiver (measured between the inner cable and the outside of the connector). When tuned to a channel on an odd numbered transponder (see http://forums.digitalinsurrection.com/forum/showthread.php?t=155280 for a mapping of channels to transponder numbers) you should measure about 13 VDC. When tuned to a channel on an even numbered transponder ou should measure about 18 VDC. In my case I found that three receivers output the expected voltages, while the fourth output 10.83 VDC regardless of what channel it was tuned to.
At this point, I thought I'd found my problem. I reconnected the three good receivers to the multiswitch and went inside to check it out. Surprisingly, I still got only even transponders!
Next I tuned one receiver to channel 271 (odd transponder) and one to 278 (even transponder) and hung a test cable on each LNB connector on the multiswitch. I found that both were outputting 18 VDC (should have been 18 VDC on one cable and 13 VDC on the other). Found the problem - bad multiswitch.
To be certain, I connected two receivers directly to the LNB cables coming from the dish with a cable extender fitting and tested both receivers. I found that both got strong signals on all transponders, thus verifying my diagnosis.
So I ended up needing a new multiswitch (~$60) and a new receiver ($49 from DirecTV with a 1 year commitment). Since I'd been lusting for a DVR for the last few months, I opted to go for that ($99 from DirecTV, including professional installation). Since I insisted on getting the two-cable connection, this required replacement of my multiswitch (a freebie with professional installation, since (from DirecTV's point of view) my 4 output multiswitch was fully used by my four existing receivers).
Hope this helps somebody as much as the other postings helped me to find my problem.