Use of Extension Cables on Roof Antenna.

[lrwinddancer]

Howdy, I am in the process of installing a Poynting 7-in-1 Roof antenna for my Pepwave Max Transit Duo Cat 12 LTE router. This is going on my 2020 Newmar Dutch Star 4081. The challenge I am up against is Newmar has a conduit from the roof to the cabinet already in place that would make the install fairly straight forward and not require me to drill any additional holes in my roof. However the 6ft cable that comes on the antenna unit is about 2 feet to short. I see TechnoRV sells a 3meter extension cable, which is an over kill. In my search for shorter cables I ran across several articles that recommend not using extension cables due to signal strength loose from the antenna to the router. Have any of you ever experienced this. I just don’t know if it is major or minor. Basically wondering how much lost I really will have? Thanks

[Jim_HiTek]

I wouldn't worry about an 8 foot extension. Just be sure you buy good cable.

Cable loss from the manufacturer:
0.35 dB/m @ 900 MHz
0.53 dB/m @ 2000 MHz
0.6 dB/m @ 2500 MHz
0.72 dB/m @ 3500 MHz

Note that 3 db would be 1/2 signal amplitude. So 2.4 meters of cable at 3500 MHz would lose around ~1.782 dB total, which would be worst case of those freqs listed and well under the 3 db. And that's well within needed amplitude for typical RF designs. I wouldn't get worried unless it was 6 db lost.

I suspect that the manufacturer put an amp there after the cable run too.

[tetranz]

Originally Posted by Jim_HiTek

I wouldn't worry about an 8 foot extension. Just be sure you buy good cable.

If I'm reading this right, we're not talking about an 8 ft extension. 8 ft total is ideally what's needed but the antenna comes with a "6 ft cable" so it's only 2ft short but the only extension readily available is 3m.

Not that it makes much difference but despite what US retailers list it as, I think the cable on the antenna is really 2m, not 6ft.

So with a 3m extension there will be 5m of cable total. That means about 3.6db at 3500 MHz or a little over half the power is lost in the cable. Maybe a little more because of the extra connectors. Admittedly that's worse case. Much better on the lower bands, especially band 71 around 600 MHz for T-Mobile where the loss would be insignificant.

Sorry, Lynn, I don't have a good answer. It would bug me to have to buy a 3m cable and leave most of it coiled up but I did a few searches as I'm sure you have and didn't find an alternative so you probably don't have much choice. There are probably companies that will make custom cables but I don't know what that would cost.

Another thought. You could probably do it with a collection of these or similar.

https://www.amazon.com/Bingfu-Bulkhe...ef=sr_1_7_sspa

Those are quite cheap so probably dubious quality and unknown loss. If you search for "SMA extension cable" you'll find more expensive ones on specialized, professional sites. Whether it would be worth the trouble compared to the 3m cable from Poynting is hard to say.

[RS505]

I routinely make up coax cables at work. One of our suppliers also makes pre-made and tested cable assemblies.

They're called Pasternack.

The different types of connectors can get confusing, but they can work off pictures. I'm sure that they can also advise about different types of coax

http://www.pasternack.com