Is it ok to use the same roof entry hole for both LTE antenna and solar panel cables on our RV?

[sawmonandnatalie]

Hi all,

We were wondering if it is accepted to use a common hole roof entry for both the:

1. LTE antenna cables ( Poynting MIMO-3-17 )
2. Solar panel cables ( combined cables of 4 x 100 W PV panels)

The hole is probably going to be going through our PV combiner box ( we have purchased a big box for this application ). We are planning to have a setup similar in this video plus the added LTE antenna cables:

Would this plan cause any RF interference signal for the LTE antenna cables and do we need to worry about these kinds of issues?
What are the best practices to keep the interference low for our WiFi and LTE connections to our modem box?

 

[snoobler]

I would direct that question to the manufacturer.

 

[HRTKD]

From my very limited understanding, DC isn't as likely to see signal interference as AC. However, that doesn't mean that DC is clean. In fact, with an MPPT solar charge controller, it sounds like it is changing the signal frequently and that could be a source for noise.

If the PV output was put through an oscilloscope, we might be able to rule out if there is noise or not.

 

[LanduytG]

That's what I'm doing too. You should not have any interference because #1 it's DC #2 the coax from the antenna shielded.

Greg

 

[snoobler]

Here's what my PV looks like at 1 minute intervals:



I probably looks much better on a shorter time frame.

 

[sawmonandnatalie]

Thank you all for your inputs. Based on your answers, we feel safe using only one roof entry hole for both.

On a related note, are there any other things we need to watch for when picking a place for the LTE/internet router inside the RV? Based on our research some devices like inverters, FET-based BMSs or the MPPT charge controller can produce RF noise that can interfere with the router signal..

 

[LanduytG]

With antenna outside you shouldn't be bothered. The only thing I would look for is putting the antenna as close to the router as possible. The shorter the feed line the less loss you will have. In my case the antenna will be mounted right by the hole going down. I will have less the 4 feet of feed line.

Greg

 

[Zwy]

Hi all,

We were wondering if it is accepted to use a common hole roof entry for both the:

1. LTE antenna cables ( Poynting MIMO-3-17 )
2. Solar panel cables ( combined cables of 4 x 100 W PV panels)

The hole is probably going to be going through our PV combiner box ( we have purchased a big box for this application ). We are planning to have a setup similar in this video plus the added LTE antenna cables:

Would this plan cause any RF interference signal for the LTE antenna cables and do we need to worry about these kinds of issues?
What are the best practices to keep the interference low for our WiFi and LTE connections to our modem box?

Personally, I prefer looking at where the cable would be most efficient to run, that is length and preferably in a spot hidden from view. I pulled my TC fridge out to run the PV cable in the space along the fridge, there was 5 inches of wasted space there. This also allowed me to not have a roof gland, I ran the cable thru the fridge roof vent. Took less than 10 minutes to pull the fridge. On the opposite side of the fridge, I cut my holes for Daly BMS display and mounted it along with a remote switch for turning the inverter on/off and a battery monitor.

 

[JoeHam]

IF you do have interference from your MPPT SCC the use of ferrites will likely cure it. Here is a good tutorial:

http://audiosystemsgroup.com/SAC0305Ferrites.pdf

From this chart it looks like material mix 52 or 61 would be your best bet:

Ferrite Mix Selection - Palomar Engineers®

Ferrite Mix Selection Guidelines Quite often we are asked which mix is best for a certain application or frequency range and there is a lot of misinformation on the internet and elsewhere regarding the selection of proper mix for a given application. Material Types There are two basic ferrite...

palomar-engineers.com

I would place a snap on choke in the combiner box and another inside the living space to start.

 

[Byrogie]

I have solar panel wires and LTE antenna wire together down vent pipe on my RV with no ill effects on either.