Tip Improving COAX cable connectivity in your RV or Motorhome

[RKins]

Interesting. So the fix was the swap of splitters from 5-1000Mhz to 5-2000Mhz and not just terminating the open ports on the existing splitter? I may have to look at that on the home setup and replace those old splitters.

Yeah, you should terminate all unused connectors in your home so you're not blasting out RF everywhere.

 

[TJ&LadyDi]

Actually, terminating the unused ports simply maintains the characteristic impedance of the circuit and prevents attenuation of the RF. The 75-Ohm characteristic of RG-6 (and similar) coaxial cable changes significantly if there are open connections at some of the ports. This cuts signal strength and results in poor picture quality and failure of the TV receiver to pick up weaker signals.

TJ

 

[Neal]

I think the biggest problem is we are now in a world of digital cable and the splitters Newmar uses is still in the land of horse and buggy cable. Coax/Cable is likely broadcasting in a spectrum that the installed splitters can't handle. I sure sound like I know what i'm talking about but quite frankly don't have a clue

 

[TJ&LadyDi]

@Neal, the cable TV channel frequencies run in the 50-550 MHz, well within the 5-1000 MHz range of the splitters Newmar uses. After looking into this a bit, I suspect the primary problem we are facing is two-fold; cheap splitters with poor isolation between ports and unterminated ports that mess up the characteristic impedance of the circuit and eat up signal.

Changing out the 5-1000 MHz splitters with the 5-2000 MHz version likely gets us a better quality unit with much better port-to-port isolation. And, terminating the open ports restores the proper impedance so the circuit doesn't attenuate the signal as much.

Just my $0.02 worth based on 40+ years of messing with amateur radio coax and associated stuff.

TJ

 

[Neal]

I wonder if the problem is coming from them sourcing their cable from a Satellite system? Read towards the bottom of:

https://www.techwalla.com/articles/cable-splitter-types

High and Low Frequency Splitters
Splitters for coaxial cable (the cable used for TV signals) are made to work with the 5-1000 MHz band used by modern digital cable signals, or the 5-2300 MHz band used by satellite TV signals. You can use high frequency splitters for low frequency cable signals, as their range includes the whole low frequency range. Low frequency splitters, however, can't be used for satellite signals.

 

[FLSteve]

Interesting. So the fix was the swap of splitters from 5-1000Mhz to 5-2000Mhz and not just terminating the open ports on the existing splitter? I may have to look at that on the home setup and replace those old splitters.

@Buster ... not sure which item is the main issue but I did both and mine went from "bad to good". If you go through the trouble of getting under that sink I would sure do both.

FLSteve

 

[Buster]

I think @TJ&LadyDi hit the nail on the head. Terminators are always a good idea as a splitter is also a combiner. Unused ports on a splitter in theory can take in stray signals and cause picture degredation but is practice this is usually not the main problem.

Unless things have changed recently, the mainstream cable companies transmit signals in the 50-1000Mhz range these days. The 50-550MHz range was the standard 20+ years ago prior to the explostion of channel options. The 5-50Mhz range is used for the return path back to the cable companies (i.e. send info back on Pay Per View purchases). Cable TV in an RV park should operate similarly although they could in theory be their own cable company and transmit differently - i.e to @Neal 's point above.

Either way, the new splitters and possibly terminators solved the problem for multiple people which is the goal.

P.S. If you ever want to see how cheap a splitter is made, just open one up and you'll wonder how you even get a signal in the first place.