Dual LNB only One reciever?

[JDahmer]

My parents have a Dual LNB system. Have replaced all wiring, dish and Recievers from top to bottom. I can still only get one ird to recieve all channels. Was wondering if the new big dish might make a difference?

[Spelled~Wrong]

I take it that you have two recievers? What problems are you having? A little more info can go along way? A bigger dish won't give you anything a smaller one won't with a "normal" setup

[JDahmer]

The reciever use to get about half the channels now it doesn't recieve any. Can check the signal and it says it is about the same as the other reciever which gets all the channels with no problems. If I switch the wires on the LNB the problem goes to the other reciever. Have replaced Dish, lnb, put in new wiring, in line amps on both lines and have tried many different recievers. I can still only get one reciever to work. Have rg-6 cable all the way down. Also have an off air antenna on the dish and diplexers as the cable comes out of the wall.

[smack]

What are the cable lengths? (LNB - > IRD)

Are you using an external grounding block?

Have you tried going from the "questionable" IRD to each of the LNB connections with a known-good chunk of cable? What were the signal readings?

Have you put a Voltmeter on the cables (13-18VDC)? Have you checked the cables for shorts (with an Ohmmeter or similar)?

When you mention that the IRD only ever got half of the channels, that would suggest that there's a splitter on the line...a bad thing...find it and kill it....

Also try losing the diplexors & going straight satellite signal...I had a diplexor flake out on me this weekend ...shouldn't happen ...but it did.

Good Luck

Scott

[JDahmer]

I tried to put in as little cable as possible(cut out all uneccesary lenghts). I know there is not more than 100 ft of cable between ird's and dish. Replaced the grounding block a few months ago. Will put a voltage meter on the cables this weekend(Haven't checked that yet). Use to have a voltage switch in the house. Still even then 1 ird would get all the channels and the other two(had three ird's at one point) would act funny and get some channels but not all. My next option is to take a spare ird and follow the cable down from the dish to see when the signal goes bad. Will a voltage meter be able to tell me the same as an ird?

[obi1]

Originally posted by JDahmer
The reciever use to get about half the channels now it doesn't recieve any. Can check the signal and it says it is about the same as the other reciever which gets all the channels with no problems. If I switch the wires on the LNB the problem goes to the other reciever. Have replaced Dish, lnb, put in new wiring, in line amps on both lines and have tried many different recievers. I can still only get one reciever to work. Have rg-6 cable all the way down. Also have an off air antenna on the dish and diplexers as the cable comes out of the wall.

I once had only 1 little strand of of shield wiring touching center copper wire at connector causing me much grief such as you describe. Once I metered wiring I found problem right away. It was especially messy for me as I was attempting to run 4 receivers(one Sony and 3 RCA's) off of a single dual lnb dish using the crummy 2 into 4 multiswitches made by Recton and RCA. Recton now has a decent switch that is electronic and not manual that does a good job(although the old bad ones are still in stores for sale). So this problem on top of the wiring short that I had gave me a fit for awhile. All is well now.

[smack]

If you detach the cable at the LNB, the IRD goes into "Searching for Satellite Signal"...the voltage (center referenced to the shield) will swing (should swing) between +13 VDC and +18VDC and back in ~ 1-2 seconds per cycle. This is one of those cases where an analog meter works a bit better than the digitals (depending on the display update time).

Work your way back, one connection at a time until it looks right.

You may also want to disconnect the IRD end of the cable at the same time, check the resistance (both ends disconnected) should be (of course) infinite. If you then short one end, you should see a resistance of ~ 2-3 OHMs per one hundred feet on a straight cable, maybe a little more if you have a couple connections between the meter and the shorted end.

Good Luck, don't forget to re-post if you find the problem...it could help someone else that's having a similar problem.

Scott

[SMOKER]

Is there an amp on your antenna? If you are useing diplexers to combine the signal , you need the diplexers for that application.Try unplugging it if that is the case and see what happens.

[JDahmer]

Made a little progress today. Found some rusted out cables so now I am back to about half the Channels on the one reciever. Took out both in-line amps(Didn't seem to be making a difference). Removed diplexer and noticed about a one or two channel difference than with(not a big change). Couldn't ever get a reading with the voltmeter. Referenced the center to the shield and other grounds and still no reading on either signal(the good reciever or the bad one). Tried both the ac and dc settings.(Tested a cell phone batt. and the phone line and got readings on both, so i'm pretty sure my cheap meter is working). Took off-air antenna out of the loop and still no difference.
As long as the cable is connected to the LNB you should get a reading, right?

Also get no signal on even transponders, but on one of the odd transponders I can get 87-90 range. The other reciever gets 90.

[Edited by JDahmer on January 8th, 2001 at 05:36 PM]

[smack]

You should be seeing the 13/18VDC at the LNB end of the cable (while connected to an IRD). If you're not, then you got a funky cable. If water gets inside the jacket, it "poisons" the cable / corrodes the shield.

What I believe you're seeing, is the 18VDC switching voltage, reduced due to cable losses, to look like what the LNB thinks is the 13 VDC switching voltage (that's why you're only getting about half the channels).

Buy a decent, pre-connectorized cable and run it direct to the dish...try both LNBs..compare the signal levels. Try as short of a cable as you can...and absolutely less than 100 ft.

If you're still not getting all channels, and the voltages look good, you should try another LNB. If the LNB connections were not properly weatherized, the connector guts (on the LNB) may be corroded.

Good Luck, improvement by the millimeter is still an improvement....


Scott