WiFi antenna mounting options

[TCL]

I've finally purchased something long-term to replace my inoperable Wirie Pro, a Mikrotik Groove and Mikrotik hAP ac lite router.

I'm interested in opinions on which would be a better location to mount the Groove--the two choices being: (a) the mast for the wind turbine or (b) the radar mount pole that is attached to the backstay. See attached photos. The height difference is negligible to non-existent and there is easy wire routing for either.

The concerns I see would be vibration, which I assume would be greater if mounted on the wind turbine mast (although the radar mount pole sways with the backstay) and that the radar mount pole is at an angle rather than vertical.

I realize that another option would be to mount on the mast somewhere, but I'm interested in thoughts on these two options before considering that. Thanks.

[I can't get the photos to rotate properly.]

[Dsanduril]

I don't like the windgen mount as shown because the antenna is parallel to the pole. 2.4GHz wavelength is ~120mm in free space, 1/4 wavelength antennas are ~26mm/1" and halfwave 52mm/2". Looks like the mounting pole would be in that range and could cause some serious interference in some directions (it may also provide amplification in other directions). If you want to go that way I'd tape it up temporarily and test out performance, trying to hit access points in several directions.

[MooGroc]

I have a Groove and I really like it, but it doesn't seem like it was built to be out in the elements long term. I just run it out a port hole and set it on top
of my stack pack when I want to use it.

I wonder how much better it would do if it was up higher.

[Auspicious]

The wind gen pole is a bad idea due to the metal pole. You could do something with the radar but you do want it to be vertical. Lowest spreader would be fine, maybe great.

[TCL]

Originally Posted by Dsanduril

I don't like the windgen mount as shown because the antenna is parallel to the pole. 2.4GHz wavelength is ~120mm in free space, 1/4 wavelength antennas are ~26mm/1" and halfwave 52mm/2". Looks like the mounting pole would be in that range and could cause some serious interference in some directions (it may also provide amplification in other directions). If you want to go that way I'd tape it up temporarily and test out performance, trying to hit access points in several directions.

Hi Dsanduril, thanks for the response. Please pardon my ignorance, but a followup question to make sure I understand:
• when you say 2.4gz is ~120mm in free space, would that mean that if I made a mounting bracket that created that space between the pole and the antenna, it should be free of interference?
Thanks

[NahanniV]

I would suggest temporary mounting for a few reasons:

Sometimes you have to fiddle with the antenna position to get the best signal. Maybe this would not be needed if it was above all possible obstructions on the boat.

Often just putting it on deck works, but sometimes I haul it up a flag halyard.

Most of these antennas will not last very long if left outdoors continually.

This technology is constantly changing, why mount it permanently ?

[skipgundlach]

My apologies for dictation. Likely there will be errors.

I have addressed mounting the antenna in my posts in the past. If you search for island time PC and my name likely you will find pictures of it.


When I'm back on the boat I can provide the proper link

[Dsanduril]

Originally Posted by TCL

Hi Dsanduril, thanks for the response. Please pardon my ignorance, but a followup question to make sure I understand:
• when you say 2.4gz is ~120mm in free space, would that mean that if I made a mounting bracket that created that space between the pole and the antenna, it should be free of interference?
Thanks

No, sorry to misdirect. The full wavelength is ~120mm, but a 1/4 or 1/2 wave antenna is not quite that long because they are not "freespace", they are physical objects. With antennas anything that is in multiples of that 1/4 or 1/2 wavelength can have significant effect on the radiation. Since in the WiFi bands these are on the order of an inch or two (or 25-50mm) it is really hard to avoid getting within some multiple of that. Especially with a pole that is 2"/50mm or so in diameter. If you can get 3 or 4 wavelengths away (so about a foot or so) then the effects become much less, but will still be present.

[skipgundlach]

OK - Here's the scoop on mine:

Unless you're going to rely on this for WiFi that is very close (like, to the end of the dock, if you're on one), higher is better.

Any nearby metal will interfere with the signal, parallel to the antenna more so, so mounting it under your windgen is particularly poor placement.

On top of a spreader isn't too bad (the mast would be some distance away if you put it mid-length, but still would provide either reflection or obscuration of signal), and is high enough for most applications.

But, back in the day when WiFi was IT (vs the cell signals and hotspots of today), I routinely connected, under way, 7 or more miles away, including south of Staniel Cay, heading West, via Sampson Cay, ~10 miles north, and on the FL East coast.

My installation avoids nearly all adjacent metal (other than the very small stuff on top) and the VHF radio gets the same benefit on the other side.

This segment of my gallery has the beginning of my mod; earlier means of mounting are shown if you wanted to see all the other stuff going on it that subgallery. Apologies in advance for more than one project happening at the same time, but it's pretty easy to figure out which part addresses your question ☺

Pictures: Flying Pig 2009 Refit /Repairs_And_Upgrades/Electronics

[sailorboy1]

I have my booster antenna mount on the side of my solar panel frame. So it’s about 10’ about the waterline. I have no trouble getting signals 1/2+ away. The distance awaymatters little most of the time anyway because now days finding an open access point with enough internet speed to be useful is the issue. I still get some use from my booster and router, but cell phone hot spot and streaming has taken over 90% of the use from it.

[Auspicious]

Originally Posted by TCL

when you say 2.4gz is ~120mm in free space, would that mean that if I made a mounting bracket that created that space between the pole and the antenna, it should be free of interference?

The issue is not interference per se. It is shielding and directivity. If you WANT directivity then you certainly care about wavelength (closer to 125 mm at 2.4 GHz). Realistically directivity is not desirable on a boat.

For good omnidirection coverage with a minimum of shielding its hard to beat a radar pole or a backstay mount. High and clear is lovely but the only antenna at the masthead should be your marine VHF. If you have a schooner, ketch, or yawl the second mast is a dandy place for you AIS antenna.

Halfway out a high spreader is also a good spot - you're trying to avoid interaction with either the mast or shroud.

Originally Posted by skipgundlach

My installation avoids nearly all adjacent metal (other than the very small stuff on top) and the VHF radio gets the same benefit on the other side.

Just no. You simply won't get enough separation with two antenna at the masthead to avoid interaction. In your case you don't know what you don't know. You almost certainly have directivity on both VHF and WiFi which is not good for either. VHF is mission critical and should not be purposely degraded. Poor choice.

[Cpt Pat]

Originally Posted by Auspicious

Halfway out a high spreader is also a good spot - you're trying to avoid interaction with either the mast or shroud.

Just no. You simply won't get enough separation with two antenna at the masthead to avoid interaction. In your case you don't know what you don't know. You almost certainly have directivity on both VHF and WiFi which is not good for either. VHF is mission critical and should not be purposely degraded. Poor choice.

Agreed. If you mount it on a spreader, and there is any possibility of fouling your halyards, I suggest mounting it pointing down - provided it's water tight in that orientation (it should be water tight, or it doesn't belong on a boat).


If it fouls a halyard, and you can't see it while hoisting, you'll destroy it while hoisting sail. (The inability to see what's happening up the mast while hoisting is the main reason I dislike having halyard winches mounted on the mast.)


I cringed when I saw the mounting right up against the wind gen pole. That's not a good placement at all.

[Auspicious]

Originally Posted by Cpt Pat

If it fouls a halyard, and you can't see it while hoisting, you'll destroy it while hoisting sail. (The inability to see what's happening up the mast while hoisting is the main reason I dislike having halyard winches mounted on the mast.)

Hmm. I don't have any problem with line of sight with mast mounted halyards and winches. Line of sight is much more often limited with cockpit led lines. If a halyard fouls a spreader mounted antenna there is a whole other problem. That is not to say that mistakes aren't made and that failure cascades don't happen.

[skipgundlach]

Originally Posted by Auspicious

Halfway out a high spreader is also a good spot - you're trying to avoid interaction with either the mast or shroud.



Just no. You simply won't get enough separation with two antenna at the masthead to avoid interaction. In your case you don't know what you don't know. You almost certainly have directivity on both VHF and WiFi which is not good for either. VHF is mission critical and should not be purposely degraded. Poor choice.

If the massive (by comparison) mast and perhaps .375 wire shroud won't interfere/interact (by inference, halfway out the spreader - maybe 3-4') what separation for a ~.040 wire VHF whip and a typical 8dbi WiFi would be appropriate?