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drrhein
04-04-2012, 04:58 PM
On my 2010 Landmark Grand Canyon the tv in the living area has poor signals on both the antenna/cable and satellite, Bedroom is Ok.
Ran an cable test on the cables and I'm getting up to 3 ohms resistance on shorted coax end to end. Way too high. Should be on the order of 1/2 ohm. Leads me to believe there's a junction somewhere. Cable starts out white and ends up black.
Anybody have any idea where these junctions are??

cookie
04-04-2012, 05:41 PM
One thing I would look at first is the f-connectors. I have seen one strand of shielding wire touching the center wire and causing poor signal strength.
Under your entertainment slide, follow the coax that is in the plastic wire loom. It comes from the outside corner on the rear of the slide.
Where it enters the belly of the coach you will want to drop the plastic belly material. Reach in, or look in and you will see the coax. There is where you will find a barrel connector for the coax.
They wire the belly of the coach first, then when they put the pre-wired slide in, they just need to connect the cables.

Peace
Dave

danemayer
04-04-2012, 07:15 PM
The cable/antenna problem is probably a separate problem from the satellite problem since the wires are separate.

Satellite runs from the UDC to the living area and as Dave explained, may have a connector as it goes into the slide. If you're using a standalone dish, I'd suggest trying it with a known good piece of coax from the dish to the receiver. I assume you have an HDMI cable between the receiver and TV; anything else is likely to be lower quality video. If the problem goes away, you have a problem with the run from the UDC to the living area, and as Dave said, it's probably in the connectors.

The coax from the cable connector in the UDC, and the coax from the roof antenna both go to the amplifier in your bedroom. Red light ON amplifies the signal for TV. The red light must be off for cable. The path goes through the amplifier connectors and on to the basement TV mount where there's a splitter behind the basement wall. The coax continues from that splitter to the living area.

I've attached a diagram of the coax wiring for Landmarks.

drrhein
04-04-2012, 10:48 PM
The cable/antenna problem is probably a separate problem from the satellite problem since the wires are separate.

Satellite runs from the UDC to the living area and as Dave explained, may have a connector as it goes into the slide. If you're using a standalone dish, I'd suggest trying it with a known good piece of coax from the dish to the receiver. I assume you have an HDMI cable between the receiver and TV; anything else is likely to be lower quality video. If the problem goes away, you have a problem with the run from the UDC to the living area, and as Dave said, it's probably in the connectors.


The coax from the cable connector in the UDC, and the coax from the roof antenna both go to the amplifier in your bedroom. Red light ON amplifies the signal for TV. The red light must be off for cable. The path goes through the amplifier connectors and on to the basement TV mount where there's a splitter behind the basement wall. The coax continues from that splitter to the living area.

I've attached a diagram of the coax wiring for Landmarks.

Yes, I ran a known good cable from the dish to receiver and all was ok, then through the coach and the signal dropped by 50%.
As I've troubleshot this problem I've found better than 3/4 of the coax connections loose..


Ok, splitters often drop the signal strength by quite a bit. I'll try bypassing that. And also check for barrel connectors, which might be loose. Thanks for the diagram!! Now if I knew just where the coax's coiled up on the roof were I'd be golden.

jbeletti
04-04-2012, 10:55 PM
...Now if I knew just where the coax's coiled up on the roof were I'd be golden.

The satellite prewire to the roof consists of 2 coax cables from a wall plate in the UDC to the roof. The roof ends of these lines are coiled above the ceiling speaker in the bedroom that is rear-most.

Pull off the speaker grill, remove the speaker screws, disconnect the speaker wires and above there, you should see two coax cables.

Jim

danemayer
04-05-2012, 06:15 AM
Ok, splitters often drop the signal strength by quite a bit.
The splitter isn't in the satellite path. It's for the antenna/cable path.

My problems were primarily with cable. But I figured if I had to open things up and work in tight spaces, I should take care of everything in one shot. I bought a kit from Amazon and replaced every coax connector I could find. Took about an hour.

rick_debbie_gallant
04-05-2012, 10:20 AM
Check all of your coax ends. I had to replace all of mine and be certain to use the proper crimping tool, not just a pair of pliers.

drrhein
04-05-2012, 11:54 AM
Ok, both TV problems found.
Satellite for LR was bad barrel connection under slide-out.
Regular OTA TV problem was backward connected splitter at basement TV mount.
What I find interesting is the number of loose connections I'm finding.

Remaining problem is amount of electrical noise on the DC system.
Previous coach was powered by an inverter/charger and we never had any problems.
On this unit the DC system is powered by a converter and when the bathroom fan is turned on I lose all channels.
when the AC kicks on I lose channel 10-1, forget the vacuum cleaner.

I'm guessing the AC noise is being passed through the converter to the DC side due to a lack of filtering.
The bathroom fan is probably on the same DC circuit as the antenna power supply. I'll add a capacitor across that.
This is borne out by looking at the DC side with an oscilloscope. We're seeing 2 VDC peak to peak when the fan runs.
Higher frequency noise with the AC.

Anybody have a DC system diagram? It could be as simple as how the converter is tied into the DC system.

Thanks guys!!

branson4020
04-05-2012, 12:04 PM
The DC output of the converter is tied directly to the 12V primary input at the back of the fuse panel. Electrically, it is in parallel with the battery.

18548

drrhein
04-05-2012, 02:46 PM
18549
No wonder! That's not right. The load of the circuit breaker panel should be coming directly off the battery (properly fused, of course).
as shown in image above, Minimum.
The converter connects directly to the battery too (Also properly switched and fused)
Monaco (My last coach) did it that way and there was NO DC noise.
The battery acts like a giant sponge, absorbing all noise (within limits) but the way it's done here the wire from the bus to the load center
acts like a giant resistor allowing all the noise to run around the DC circuits and to be coupled from the converter.
When the converter is properly tied on the battery first, the battery will absorb most noise before it's coupled to the system.
You're right when you say on paper they're the same, but electrically, they're not. Every inch of wire has resistance and it adds up.
If you look at your car, the alternator goes to the battery, not the fuse panel. Same for airplanes and most other vehicles.
Another example, in ham radio they say to always hook the radio directly to the battery post, for the very reasons stated above.

wdk450
04-05-2012, 04:20 PM
Ok, both TV problems found.
Satellite for LR was bad barrel connection under slide-out.
Regular OTA TV problem was backward connected splitter at basement TV mount.
What I find interesting is the number of loose connections I'm finding.

Remaining problem is amount of electrical noise on the DC system.
Previous coach was powered by an inverter/charger and we never had any problems.
On this unit the DC system is powered by a converter and when the bathroom fan is turned on I lose all channels.
when the AC kicks on I lose channel 10-1, forget the vacuum cleaner.

I'm guessing the AC noise is being passed through the converter to the DC side due to a lack of filtering.
The bathroom fan is probably on the same DC circuit as the antenna power supply. I'll add a capacitor across that.
This is borne out by looking at the DC side with an oscilloscope. We're seeing 2 VDC peak to peak when the fan runs.
Higher frequency noise with the AC.

Anybody have a DC system diagram? It could be as simple as how the converter is tied into the DC system.

Thanks guys!!

DRRHEIN:
The bathroom fan runs on 12 volts DC and its interference with TV signals is a known problem. The little motor has brushes that put out a lot of electrical arcing noise. My fix is to wire in a .001 microfarad, 15 volt (or better), ceramic capacitor across the power wires to the motor, as close to the motor as you can get it. This capacitor acts as a short circuit to the AC sparking noise, but acts like an open circuit to the 12 volt DC supply.

drrhein
04-05-2012, 04:23 PM
I agree, in-process of doing that. My previous message was regarding the issue where the ac cycles on (or hair drier etc) and the 12v drops out.