You are here

Inexpensive 2.4GHz Antennas

10 posts / 0 new
Last post
KV3T's picture
Inexpensive 2.4GHz Antennas
Hey all,
I have a few 2.4GHz MIMO nodes.  One with a sector and two without good antennas, simple tiny screw on .  Ideally they would all be be onmi.  These devices are Ubiquiti Rocket M2.  I don't have the budget for three $150 antennas, but I'm also curious about why those are so expensive.  If they are really worth that, maybe it is worth getting one and then two cheaper ones.  I'm also curious if there is anything wrong with getting two single channel antennas and then somehow physically cross polarizing them.  Mostly, just curious what other people are doing.  One of these nodes is a portable node that will be a local relay to any other nodes in the area to be deployed at an event, with a DTD connection to a 5GHz node (LHGXL) to connect to a larger network.  One is the main one that I use in my house for day to day mucking about.  And I'm not even sure how or why I ended up with the other one.

I'm surprised with the poor performance I'm getting with the sector antenna in my house.   I know it is too much antenna, and obviously the directionality is far too much for my use case, especially in the vertical plane.  I'm hoping for good connection thru a few walls and up a floor.  Turning the power way down didn't help.

For the portable node, the sector would probably do well, but I don't want to commit to having that node at the edge of the coverage area.  A bit more flexibility would be ideal, in case for example, the perfect location for the node is at the middle of the coverage area.

Maybe I get one good sector and one good omni and then switch them out as needed?

Sorry for the rambling, but I'm very curious to hear everyone's opinions.
nc8q's picture
Inexpensive 2.4GHz Antennas
"... the directionality is far too much for my use case, especially in the vertical plane. I'm hoping for good connection thru a few walls and up a floor." Hi, Casey: Sector antennas usually have equal horizontal and vertical beam pattern. To cover 'up a floor', this antenna might need to be on the opposite side of the house. The big sector antennas I usually see with a Rocket likely have built-in down-tilt. Again, not suitable for "up a floor". Perhaps those itty-bitty antennas usually found on home routers will give you the "up a floor" coverage you seek. I hope this helps, Chuck
KV3T's picture
I may have rambled too much
I may have rambled too much to clearly ask the question above.  To ask the question a different way:

If you were to drop a portable relay node in the to service a 5000sq ft site, with a 2.4GHz node on a tripod that goes up to maybe 8' high, what antenna would you recommend for a Rocket M2.  Assume the 'back haul' is coming in on 5GHz and need not be serviced by this antenna.

If the answer is the expensive one (AMO-2G10 or AMO-2G13) that is ok.  I just want to be sure I'm not missing a less expensive option that is in vogue with the group.

I couldn't for the life of me tell you what, when, or where, but I know I heard on a podcast probably 5 years ago, about a municipality, I believe in the bay area, that has some portable nodes deployed in shipping containers or something of the sort that have a back haul link on 5GHz and then support local services.  I don't recall any more details than that, but if those nodes have a 2.4GHz node on them, I'd be curious what antenna was selected for that application.

Separately, if anyone has any insights into what is going on inside that antenna, physically or electrically, I'd be curious to learn more on the topic.  Heck, I'm a ham.  Maybe I can make something.
K6AH's picture
Use a regular WIFI access point...
5000sf is tiny.  You could use a regular WIFI node, or any of the lowest priced AREDN-supported devices will cover this area. Look to M2 Bullet or even GL-iNet AR150.  Do not use a sector antenna... they are way more money and will require an M2, a more expense radio.
nc8q's picture
You could use a regular WIFI node.

5000 sq. ft. ~= 80 ft diameter circle.
A $20 off the shelf home Wi-Fi router would cover this area.
Connect the Wi-Fi router to the LAN port of the 'backhaul' device.

KV3T's picture
I'm sorry.  I must not be
I'm sorry.  I must not be asking this question the right way:

I'm asking for recommendations on general purpose, weatherized, 2.4GHz omni antennas for Rocket M2 devices (that I already own).

The application is to be used in various scenarios, at home, in the field, probably at our field day site, to support a command tent at a public service event, etc.  I'm not going to have a unique node for each site shape / size / use case.  I'm trying to build at least one 2.4GHz omni node that will cover as many of those use cases as possible.  I can turn down power if needed.

I'm asking if the expensive Ubiquiti omni antennas are the best choice / worth the money, if there are alternates out there, or if I should just go with something cheap, like the 2x Mikrotik ACOMNIRPSMA, can I make my own, or something else I haven't considered.

I already have one sector antenna (AM-2G15-120) and have already identified that that isn't meeting my needs.

Thanks for the help.
nc8q's picture
Hi, Casey:
Hi, Casey:

"...especially in the vertical plane. 
I'm hoping for good connection thru a few walls and up a floor. 
Turning the power way down didn't help."

"I can turn down power if needed."

None of the antennas you mentioned support vertical coverage.
All concentrate the signal in the horizontal plane.
"I'm not going to have a unique node for each site shape / size / use case. "
Ergo, your hopes of one portable station working in all your examples may not be realized.

I noticed that you mentioned turning down the power...twice.
What was this action supposed to do?


w6bi's picture
Vertical coverage
I recently had a need to spread our network up into the attic (for a 'smart' air conditioner).   I took an old Nanostation NSM2 (with stock software) and just laid it on its back pointing vertically.  Worked out well.
That might work for you.
Orv W6BI
KV3T's picture
Good morning Chuck. My logic
Good morning Chuck. My logic there is that I have 'too much antenna' you can turn the power down to compensate. I could imagine an rf world where you could overload a device. Maybe that isn't a thing with aredn. My point about not having unique nodes is that I'll use the rocket node for each application, and change out the antennas to meet the need. At home is relatively easy because i live in a normal size house. I have a sector if i need it. I don't have an omni that i trust for that rocket device, thus the request for a suggestion. The AMO-2G10 in some scenarios lacking the vertical coverage might be a problem. I'm curious how others would navigate this specifically with the Rocket device we already have. Do i just find some quality looking home wifi antennas and go with that? I'm concerned if it starts raining at our event those style Antennas might allow water ingress into the node. This is primarily a question about what is ideal in a field portable application. This node will be the primary node supporting small a command tent 'campus' at a public service event this summer. Will be up and active for about 40 hours rain or shine in August. In Chicago that means minimally it will see condensing humidity twice. The antennas i have in there now are definitely not up to that task.
KV3T's picture
I picked up two Mikrotik
I picked up two Mikrotik ACOMNIRPSMA antennas.  Like all Mikrotik hardware, they were cheap, so why not.  I couldn't find any test data, but they might have adequate vertical coverage, and I would expect the lower gain won't cause any problems for any of my use cases.

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer