Coax between 12VDC amp and antenna is not working in 92 Excella

[Re-Pete]

Hi, my RG-59 coax cable between my 12VDC wallplate amplifier and the crank up roof antenna is not carrying a signal. It is not showing ground continuity. The interior copper wire has continuity, but the braided ground wire does not. I've eliminated all of the cable above the roof but for 8" where it exits the roof. The ground break is occurring somewhere inside the wall or ceiling. I can also tell you that the coax exiting the roof is a different cable (gray with black letters) than the one coming out of the wall (Black with white letters) where it attaches to the amplifier. I talked to a Mark in Jackson and he said they usually installed a splitter inside the wall which might account for the difference in cable colors.

I'm wondering if anyone else has had a similar problem and how they fixed it.

[perryg114]

Are you getting a signal? My wire broke where it goes through the roof and I ran a new one through the fridge vent and bypassed the trailer system.

Perry

[lewster]

Airstream uses several cable splitters in their RG-59 runs. track them down and replace as necessary. One will usually be at fault!

[Re-Pete]

Originally Posted by perryg114

Are you getting a signal? My wire broke where it goes through the roof and I ran a new one through the fridge vent and bypassed the trailer system.
Perry

Hi Perry, There is no signal from the antenna. I was stumped at first because when I checked voltage at the cable connector at the antenna end it showed 12V+, it was only when Mark at Airstream Technical said it could be a bad ground and another friend mentioned checking continuity that i discovered that although there was current running through the positive copper wire, there was no negative ground to make it useful.

I've also considered the refrigerator roof vent. A previous owner ran cabling for solar panels he installed through it and the refrigerator compartment is directly beside the credenza that the 12VDC wallplate is located inside. So, yes, I'm considering that option.

BTW, I did by-pass the factory installed coax and ran one from the amplifier out through the door and up to the antenna and pulled in like 35 stations. So, I know the antenna works.

Pete

Originally Posted by lewster

Airstream uses several cable splitters in their RG-59 runs. track them down and replace as necessary. One will usually be at fault!

Hi Lewster, What you say jives with what Mark told me, but Mark was not sure I could get to anything inside the walls or ceiling. I have no clue on how to access and replace them. If you or anyone else can provide advice on how to locate and replace the splitters I'd certainly appreciate it. I have the vinyl skinned aluminum interior panels on my 92 Excella. The wallplate is located inside a built-in credenza which is tucked into an 18 inch deep space beneath a window situated between the cabin door and the refrigerator compartment. The back of the credenza is the refrigerator compartment wall.

[Keith Gantt]

Ground the shield of the ant coax to the skin of the trailer. Works well for the times I've fixed this for customers. The shield is the negative return for the twelve volt power for the booster . If it's grounded is should work.


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[Al and Missy]

While grounding to the skin can fix the 12v problem it doesn't provide the shielded connection that the signal needs. It may work, but you may experience more interference from electrical noise and the transfer of the new digital television signals will be degraded. If it works, great, but the best option is to find the break or run a new cable.

If there is any evidence of leakage or corrosion at the antenna, cut off the old connector and replace it. The ground is often an aluminum foil that can corrode and may have failed.

If the trailer has had an amplified antenna in it from day one there shouldn't be a splitter between the antenna and the power supply. It takes a special splitter to pass the power. But the interruption is in the center conductor, not the shield.

Al

[AtomicNo13]

I had something similar happen. Mine was a 91 34'
Turned out to be the wall plate in the bedroom with a bad crimp on an end way back there.
It defied all logic but fixed the problem..... Could also then use cable and switch between the 2 and actually have it work!

[blkmagikca]

It can also be the co-ax connector. JC changed the one which attaches o the antenna and it vastly improved my reception. The connector at the antenna end can get corroded and may not be immediately visible. Since the connectors are quite inexpensive, clipping off the bad one and crimping on a new one is worthwhile.

[Re-Pete]

blkmagikca, Al and Missy,
I'm sorry I wasn't more clear. I have already cut back the cable above the roof except for an 8" nub I left to connect new above the roof coax to. I didn't mention it, but first I tried just replacing the connector at the antenna end of the coax. Then I tried cutting about 6" more off, still no luck, so, I cut off the rest off the roof cable that ran through the crank up antenna stand and checked the end of the nub. Nada, no signal and no ground/negative continuity. Leading me to surmise that the break is somewhere inside the ceiling or walls. As I was rereading this I realized that I have not replaced the connector on the coax that connects to back of the amplifier. There's not much to work with, but I guess I should try that also.

If that doesn't work:

Keith, I will try your suggestion of grounding it to the roof. That certainly makes sense, seems simple and if it works well, a good fix, bearing in mind what Al and Missy added. Otherwise it looks like might only sensible long term alternative is to abandon the old antenna coax and run a new one up through the refrigerator vent on the roof as I have no idea of what's involved in removing the coated aluminum interior wall panels and trim.

AtomicNo13, For some reason there is no longer a coax in to the amplifier for the rear cable connection. A PO added satellite coax at some point and ran it from the tongue to new and separate wallplates at the front and rear TV's. When I am someplace that cable is available I just hook up to the new satellite coax connection and move my coax pigtails for the TVs to the new connectors. I'll look into you suggestion about the bedroom TV, but it seems to have a solid connection from the amplifier to the bedroom and gets great reception as does the other TV when I run a by-pass coax to the antenna.

[Re-Pete]

So, I tried replacing the connector at the Amplifier end also. Nada, no change. The disconnect to the ground was clearly beyond my reach inside the wall or ceiling, but thanks to Keith Gantt the solution was both simple and elegant.

Ladies and gentlemen we have a winner!

Originally Posted by Keith Gantt

Ground the shield of the ant coax to the skin of the trailer. Works well for the times I've fixed this for customers. The shield is the negative return for the twelve volt power for the booster . If it's grounded is should work.

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Keith's suggestion of grounding the ant. coax shield to the skin worked like a charm. I was able to run a ground (14 gauge insulated wire) crimped inside a coax connector on the roof to some angle aluminum fastened to the roof skin. I added an eye connector to the loose end and used an existing bolt to get a nice tight connection to the angle aluminum fastened to the roof by a PO. The ground wire worked like charm.

This is a great and fairly simple workaround to an otherwise difficult to remedy situation. It was certainly a heck of a lot simpler than all the gyrations that I thought I'd have to go through, rewiring, etc.

Results: The picture on my LCD TVs are pretty crisp and clear (good enough for me anyway). With the AS currently sitting in my driveway in Virginia Beach, VA I'm picking up 35 channels.

Details: To go into just a bit more depth for those who maybe interested. I used on alligator clips connected by insulated wire wire to test this out first and it worked. So, I pulled a couple of feet of insulated 14 gauge strand wire off a small coil and fastened an insulated eye connector to the end I attached to the body and stripped about 1/2" of insulation off the other end and pushed the twisted copper strands up under the metal jacket of the coax connector. Then I crimped the connector onto the coax. I skirted some waterproofing dielectric cream call "STUF" into the connector connections before twisting them together (suppose to seal out water intrusion) and then coated the bare connectors with Liquid Electrical Tape also waterproof. I zip tied the ground wire to the ant. coax and to a large cable running from one of our solar collectors, to keep it from flopping around in the wind. Hopefully this fix will last a good while.

Thanks Keith, you're a life saver.

And thanks to all of you that responded and shared your knowledge and suggestions.

Antenna's fixed and the Earthship is all winterized and ready for storage until late January when we head down to Florida for a couple months of fun in the sun.

[Keith Gantt]

Life can be easy if you choose, sometimes it makes sense to take the easy way out.
32 years of looking for answers in automotive,Rv electric entertainment experience helps.


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