Masthead mobile internet/phone antennas

[GulfCoastT]

Originally Posted by Jerry Woodward

Since cell towers are well, towers, and then generally mounted on hills at the highest point, I wonder whether you gain anything by mounting a cellular antenna at the top of the mast. I think the angle from the cell tower down to the boat would be pretty much the same whether to the top of the mast or to the stern rail. If you are far enough away to make the earths curvature come into play, I don't think you would be receiving a cell signal anyway. I have mine mounted on the stern rail and it has been working great off the west coast of Florida. Of course, I have never directly compared stern vs mast mount.

I am no expert and I would love to hear an expert discuss this issue.


I think the more important issue is that you get a MIMO omnidirectional antenna (two antennas inside a radome) and run two coax cables (they are pretty thin). Here is my antenna, very well made and works well.


https://www.semiconductorstore.com/c...dproduct=71870

Hi, Jerry, How offshore on the West Coast of FL can you get a cell signal with your antennae mounted on the sterm rail?

[GulfCoastT]

Originally Posted by Wotname

Just found this, I think one can do better but as an off the shelf item, it seems OK.
https://www.youtube.com/watch?time_c...&v=TWg2_M_SbfE

The trade off is always height vs coax length vs cost

So I want to mount the cell antenna on the mast but I have a VHF antenna on the mast. Those two things can't be next to each other, right? What's a gal to do?

[Sojourner]

Originally Posted by GulfCoastT

So I want to mount the cell antenna on the mast but I have a VHF antenna on the mast. Those two things can't be next to each other, right? What's a gal to do?

Put one on the mizzen?

[Pelagic]

I've got this antenna ordered for phone modem. W/15m cable to go on upper aft spreader.

The claim 17db Gain, but we will see

[svmobert]

How high are you mounting that dome? A masthead install with those small diameter cables will suffer lots of signal loss from the cables.

Originally Posted by Pelagic

I've got this antenna ordered for phone modem. W/15m cable to go on upper aft spreader.

The claim 17db Gain, but we will seeAttachment 204822Attachment 204823

[svmobert]

To answer OPs question. Yes higher is better as long as you keep cable losses in check.

A 75ft run to the top of a mast using LMR-400 is doable with a high gain antenna. The ones I most like right now are the Poynting OMNI 400.

Shakespeare makes a mast mount that extends it about a foot or so so you can mount your cell antenna away from the VHF.

If you are staying in North America, you can also add Wilsons Pro M2M inline booster between the antenna cable and the router device you connect to. This will add about 15db gain also.

I'll need to research Pelagics dome antenna to see about it's specs but anything claiming 17db for cellular frequencies is automatically suspect, and including 15m of 240 or lower spec cable is doubly so.

[Pelagic]

Originally Posted by Sea-TechSystems

How high are you mounting that dome? A masthead install with those small diameter cables will suffer lots of signal loss from the cables.

The supplier said 15m cable was maximum recommended so I am "assuming" that they would have tested that length and calculated maximum but acceptable loss.

The other choice of pre-made cables was @ 10m

If I used the full 15m cable it would mount on upper spreader 11m above the Pilothouse.

Would the 17dB gain claim help to minimize cable loss?

If not, I could always mount on lower spreader @ 6m.

I just ordered the 15m of cable set to have the upper option

Thanks for researching.... I'm depending on my IT guy to have sourced correctly.

Is Delphi a reliable manufacturer?

[swampbush]

Originally Posted by Pelagic

The supplier said 15m cable was maximum recommended so I am "assuming" that they would have tested that length and calculated maximum but acceptable loss.

The other choice of pre-made cables was @ 10m

If I used the full 15m cable it would mount on upper spreader 11m above the Pilothouse.

Would the 17dB gain claim help to minimize cable loss?

If not, I could always mount on lower spreader @ 6m.

I just ordered the 15m of cable set to have the upper option

Thanks for researching.... I'm depending on my IT guy to have sourced correctly.

Is Delphi a reliable manufacturer?

Lower frequencies travel much further than the higher frequencies. What is important is the gain at 700mhz and with an omnidirectional antenna that needs length. I use this one. Note that the specs have the gain for each frequency not just a blanket claim. https://blackhawkantennas.com.au/marine_antenna/
Those little domes are for use in a city to get better reception and faster data on the higher frequencies. Cable losses are also lower at lower frequencies. Once you get more than 10 or 20 miles out there will be nothing but low frequencies for the most part. I can get reception in Australia at distances of 90km or 45 miles. My modem allows me to pick which frequencies to use and there is nothing except 700Mhz 4G or 850Mhz 3G once you get away from the coast. Mast height also helps as the towers are often below the horizon. Also many anchorages are tucked in behind a headland and the mast height allows some reception.