Wanted to weigh in here a bit since this is literally what I do. First, all LMR cable (Times Microwave) is considered low-loss cable, but that really means it's low loss at higher frequencies than other cables at the same or similar diameter. VHF operates at much higher power AND lower frequency compared with Cellular and WiFi. VHF frequencies (~150mhz) suffer far lower losses through cable compared with higher frequencies.
RG8X @ 150Mhz at 20m = 3.0db loss
RG213 @ 150Mhz at 20m = 1.6db loss
RG213 @ 2000Mhz at 20m = >7db loss
LMR400 @ 2000Mhz at 20m = 4.0db loss
LMR-195 has higher loss than LMR-240 which has higher loss than LMR-400, etc. While an LMR-195 cable at 20ft will "work" it introduces ~4db signal loss. Unless you compensate for that with a high gain antenna you are likely reducing the overall signal strength to the router/modem vs a direct attached near zero gain whip antenna..
Let's assume you have a masthead antenna with a 20m cable (~60ft). Typical cellular frequencies run from 700-2500mhz. Higher frequencies suffer higher losses though.. So I usually make calculations for 2000Mhz.
At 20m, 2Ghz (2000Mhz) you end up with cable loss approx..
LMR-195 = 11.2dB
LMR-240 = 7.7dB
LMR-400 = 4.0dB
Now, assume you put a medium/high gain wide-band cellular antenna on the masthead that nets around 7db of gain. With LMR-195, your net gain is negative 4dB. But with LMR-400 you have a positive gain of 3db at the antenna, after accounting for cable losses, plus you have the height.
Compare that to a black paddle/whip antenna that comes on a typical cellular router which has 1-2db gain. On average you have more gain at the masthead (plus altitude) using LMR-400 than the router's included antenna.
Now let's compare 3m arch vs masthead.. Assuming you also make the cable smaller..
Rear Arch (10m LMR-240 and 7db gain antenna)
LMR-240 @ 10m = 3db gain
Masthead (20m LMR-400 and 7db gain antenna)
LMR-400 @ 20m = 3db gain
So if you upsize the cable for the masthead install, you have the same net gain AND you have the height, and you lose the interference from the vessels superstructure (mast, rigging
, etc.) however minor it may be.
This assumes of course you are willing to buy the $240 high gain antenna, and the $70 of LMR-400 cable. You can also add boosters. For example the WilsonPro Connect 4G has 15db gain and is installed inline.. So it compensates for the cable loss and adds additional gain on top of that for about $250.
All in you'd spend about $500-600 for a really good masthead high-gain antenna setup (not counting the router itself). Yes it's costly, but you'd net out far more connectivity than cheaper options. That may not matter to some, but for others that really need to be able to stay connected while cruising, it could be the difference between staying at the dock
and actually being out on the water
Antenna height does matter, not just for distance from the coast (ie: 20 vs 30nm offshore in the ocean) but also for challenging terrain. If you can get the antenna up high enough, you can compensate for cliffs and hills that would otherwise block the cellular signal (actually attenuate the signal) too much to be usable.
Just some things to thing about.
Now, regarding the components that were recommended...
Poynting is great.. But the 600 isn't not built for marine
use.. If you want a similar high-gain Omni MIMO antenna, you should use the OMNI 402 instead.
Second. MIMO antenna has 2 elements and two cables. If you put on at the masthead, you will need to run TWO cables up the mast. You may not be able to stuff 2 x LMR-400 cables up the mast. You'd be better off with a non-MIMO antenna and a single
cable (OMNI 400). If you really want to use MIMO, run 2 x LMR-240 cables up the mast instead and add inline cellular boosters at the bottom to compensate for the loss. Since you are in Europe
you will need to source some appropriate boosters for your area. The WilsonPro Connect 4G units I mention above are for Americas.. You need an EU booster, ideally a 5-band unit to cover 3G, 4G, LTE.
Technically any cellular router will work. It comes down to the LTE modem
(which the one you not has Cat6 LTEA, that's good) As long as it supports the frequencies and SIM card you carriers use, then you should be fine. Secondarily the user experience (ie: ease of use) is wildy variable across cellular routers. Some are infinitely better than others when it comes to ease of use.
The extension cable you reference, being LMR-195 is fine for short distance but you really should consider larger cable for a long run (as I have mentioned above). And as mentioned by others, a professionally pre-made cable of the correct length would be a great idea. The Poynting OMNI 402 and 600 antennas have 6ft of LMR-195 cable preattached. If you extended that to 20m with the same size cable you'd have a cable loss of 11db, with just a 6.5db gain antenna, 4.5db net loss.
Another note.. When it comes to signal power/gain.. a 3db gain is ~ double the power.
Overall recommendation.. If you really care about being connected in remote
places, and have the money
, don't skimp on the cable. But you need to figure out how much room you have in the mast for additional cables.. You are likely to be limited there. One low loss cable is better than two high loss cables.