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72 Posts
Discussion Starter · #1 ·
Let me get a few things out of the way first:

1. Yes, this is a Sat C install question;

2. Yes, I have searched/read the forum messages on Sat C installs;

3. Yes, I am an idiot/bonehead on DBS wiring;

4. With the above said, I'd appreciate not being flamed too much...

Ok, if your still with me, I apologize for the above but with the forum responses people receive today I'm just trying to avoid stepping on any delicate toes. So on with my situation:

DirecTV oval dish, 5 x 8 powered multi, Tosh DTS-3000, 2 x Philips Directivo's and no runs over 60'. Currently receiving HDTV via sat and ota. The original multiswitch on the dish was a 4 X 2 which I've wired out of the system by running 4 lines of RG-6 (2 from each LNB) directly from the dish into my basement where the 5 x 8 multiswitch is located (as its not weatherproof). This has been working flawlessly.

Called DirecTV and ordered the Sat C with install. Two installers showed up yesterday (unannounced and unscheduled) to install stating, "Everyone at the office is interested in this install as its the first our office has done." Then they asked, "So, what does a Sat C kit give you anyway?". While the installers were pleasant enough (really good guys it seems), the install went down hill from there.

After reviewing my setup, they install the Sat C LNB into the dish and run a line from that down to my 5 x 8 multi. The following is how it was wired from there:

- Mulit has 4 inputs labeled as

"A" - 14V

"B" - 18V

"C" - 14V

"D" - 18V

- Sat C kit combiner (Diplexer?) has two in ("Sat C") and ("in B") with one ouput (out "B")

- So, line from Sat C and my line from multi "B" are place into diplexer, and installer makes an RG-6 cable (replacing the RG-59 kit cable) from the diplexer and run into my multi's "B" input.

The DST-3000 was unplugged for the install, then powered up and the dish type was set to Oval with 3 LNB's. Signals from 119 and 101 were 86 and 60, but 110 signal was ZERO. A quick check of the available stations INDICATED everything was OK otherwise (See below).

After calling their office the installer thought it might be an equipment problem so he tried a new Sat C LNB (they brought a kit along not knowing that Directv has already sent me one), and a new sat C diplexer. Still no signal on 110. They then left, stating they would get back to me after "researching" this type of install.

After they left, I noted that all the stations in fact were not available. I recall I could receive 199 & 509, but not VH-1 (can't remember the channel number) which resulted in a searching for satellite message.

I then removed my "in from dish" line "B" from the diplexer and put it back into the multi input "B" and everything was back to normal. After reading forum messages, I also checked the installer's lines for shorts and the wiring seemed top notch (note though, I did not check the connection at the "C" LNB on the dish on the roof).

So, if your still with me... : )

A. Any ideas on what went wrong? The install seems like it should be simple enough;

B. I did try switching the setup so that the diplexer used my input LNB "D" inplace of "B" in the setup, but this brought the entire system down (no signal from sat 1 or 2).

C. Is there a clue in which channels I was receiving? (Possible the odd ones - though I can't remember the channel for VH-1);

Any help is GREATLY appreciated. I have no big confidence in me figuring it out for myself, and even less in the installers ever calling me back. Thanks in advance...

Premium Member
12,981 Posts
I think I'm with you on this.

FYI- I installed the Sat C kit back during the beta test period and had absolutely no problems. Today, the same LNB is not working at all. I have done some recent extensive tests and have not been able to determine what is wrong here so don't feel bad. My next series of tests will be to do the substitution process which I have not done yet because I don't have any spare Sat C's or multiswitches to substitute. Other than the sat C non-signal the multi switch is working fine here so I doubt I have a problem with the multiswitch.

Anyway, back to your problem.

The connections seem to be right and the connection to the Diplexer from the two LNB's B and C are well marked so if these installers weren't drunk or illiterate, I'm sure they had everything connected correctly. There are some procedures you should follow during the setup to verify proper sat C is to be recognized by the receiver. Be sure to:

1. Do all installs of LNB's with the receiver off to avoid possible shorts of the cable blowing the 18vDC supply on the main coax. Once all connections are in place. Turn on the receiver.

2. Go into the setup and select the 3 LNB dish. Some people have had to power down with the power cord pulled to reset to recognize the 3 LNB at this point but I naver had to.

3. Now go to channel 90 and see if you have a title bar that says Triple LNB check or something like that.

Look for Searching for satellite signal. If you get that you may have one of two problems.

A- Your dish alignment is not tight enough to get good signal on all three LNB's

B. Some unknown electrical problem with the wiring or the LNB's ability to heterodyne the transponder frequency to the 119 LNB TP frequencies.

4. Now go to your dish pointing and check the transponders signal. The thing to look for is as follows:

On the 119 look for TP's in the upper 20's and low 30's. Pay particular attention to the signal on the odd and even numbers. This is important. If you have odd but not even, I would bet they have the diplexer wired backwards. Check this out. 509 and 199 are the same so check on 376, I recall and this would be the other tp, I thin even and if you have no signal on 376 but do have 199 then this is a good indication that the diplexer is backwards.

You indicated that the diplexer connection was to "B" or the 18 volt of the 119 LNB and this is correct.

You also stated that:

"After calling their office the installer thought it might be an equipment problem so he tried a new Sat C LNB (they brought a kit along not knowing that Directv has already sent me one), and a new sat C diplexer. Still no signal on 101. "

I think you made a typo here and meant to say "Still no signal on 110"

Back to what I have done:

I also did the following test in absence of the substitute LNB. I was able to use a sat meter in line and found I do have signal from both the B and C LNB's but it appares that this signal is not recognized by the receiver. MY guess at this point is that the Sat C LNB is not yielding the proper heterodyned frequency to be recognized as TP 8,10, and 12 on 119.

You should know that you are not actually seeing the 110 TP but the signals as they appear as 119 TP's to the receiver. But the LNB must see the right birds at the proper angles. This is why it is important to make sure you optimize your signals for 119 and 101. In My Opinion you have very low signals but I'm comparing with numbers on a DTC-100 so you should compare notes with others using the same receiver. For the most part you should have very similar signal strength as others in the same latitude. FWIW I get 95-7 on the 101 and 88-94 on the 119. When the Sat C worked a year and a half ago I had 82-88 on the 110 acording to my notes. My 101 and 119 signals are the same as before yet I now have 0 on all three of the 110 (119) TP's.

I also have done additional testing on the resistive loads on the LNB's the Diplexer. I have logged voltage drops across the multiswitch and diplexer. The voltage levels are low but the same as they were when the LNB was working 18 months ago. Note that in order to measure the voltages one must have the proper TP selected that triggers either the 13v or 18 volt and the 22Khz tone will select either the 101 (no tone) or the 110/119 22 Khz tone. All this on mine is working properly.

I hope I have given you enough info in one place to help you resolve your problem. On the practical side, you need to make sure the installers haven't placed cables with non-connections or shorts. I have seen partial shorts that load the 18v down to a very low voltage that will prevent the LNB from working on one TP but not the others. (eg. Odd works even does not) Note that these are the clues in where the problem lies.

If you find signal on all odd and even TP's on both 101 and 119 but nothing on 8,10,12 of the 110 test then you may have a problem similar to mine.

I'm waiting on another sat C LNB to perform more testing.

Asside from the technical issues- You have one other option. Your problem is really DirecTV's to resolve since they have hired the "professionals" to do the install. If I were you, I'd be spending most of my time on DirecTV's tail to get someone that knows what they are doing. If you get involved then you may confuse the issue as to whose job it is to do the install. Something to think about.

72 Posts
Discussion Starter · #3 ·

Thanks very much for the reply. You are correct, I did have a typo, it should read "no signal on 110". I will correct my message.

If I have good weather this weekend I will likely venture onto the roof and check the "C" LNB connection at the dish, then recheck (for a second time) all the other connections. I don't have the necessary skills or equipment to do the detailed system exam that you have done, which I must compliment you on! I haven't rebooted my DST-3000 since selecting 3 LNB's, but I don't think this is the problem as I was missing some channels (VH-1 was the one I could recall) when the "Sat C" line was hooked to my multi. Wouldn't that indicate some sort of wiring issue?

Your point about getting on DirecTV is well taken. I just have a habit of thinking I can solve a problem with a little self help. If my simple cabling checks don't resolve the problem, you can rest assured that I will be asking DirecTV to get someone out who knows more about "Sat C" installs. Unfortunately, I believe the installation company that came out has exclusive coverage for DirecTV in the entire state of Michigan!

Guess my next question is, "How does DirecTV respond to these problem installs when the customer has changed the basic install system?". Since my original basic install in September 2001 had a dish with a 4 x 2 multiswitch (damn cheap dish), I changed the system to the 5 x 8 switch and ran all the cabling indoors since the switch was not weatherproof. Do they take a "hands off" stance if a customer has "customized" the system? I mean, this really isn't rocket science, but I can see some companies claiming that since you changed the system they won't back anything connected to it. Or they can just claim you have a crappy multiswitch and be done with it. Anyone with any experience with DirecTV on this?

Anyway, good luck to you in solving your situation. I'd be pleased to hear how you end up solving your "Sat C" problem and I will be sure to post any solutions that resolve mine! Thanks again.

39 Posts
The 18V lead from SAT-B is disconnected from the multiswitch and connected to one of the combiner inputs. The SAT-C LNB is connected to the other. The combiner output is connected to the vacated terminal from the 18V SAT-B lead. It matters which SAT-B lead you use. You must use the 18V. Good luck.
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