Max transit cat 18 antennas

A few questions about the brand new max transit cat 18 device:
1.) what is the max upload speed
2.) does it use multiple antennas to upload as well as download
3.) looking at using yagi antennas. Would you need four separate yagi antennas for optimal performance? Would you “Y” connect into a pair or even a single yagi antenna?

1.) Not sure about this, but encryption and SF/VPN overhead will play a part

2.) It uses MIMO - so each antenna (x4) will transmit and receive (upload / download)

3.) Most of the 5G LTE CAT18 antennas will be either a panel or an omni antenna (most will have 5 cables - 4x4 MIMO + 1 for GPS). If you are trying to build some sort of yagi cluster, you would need 4 MIMO (probably wideband) yagi antennas, and you would straight cable them to each of the cellular ports on the Transit. I would NOT recommend using a “Y” at all. If you can get the gain and mobility out of an omni solution - you may want to explore that route.

Am I misreading your “Y” suggestion? Are you trying to manually polarize with 2 yagi’s in each of the 4 directions, with a total of 8 antennas?

No, I was wondering if I could get anywhere with the cat18 without buying more antennas.

My current setup is a cat6 LTE-A br1 mini with a pair of yagi antennas, one on cellular main and one on cellular aux. I believe I was told that my current BR1 mini uploads using only the cellular main antenna. I have the two yagi antennas at 90 degrees to one another.

I ordered the cat18 max transit this morning to give t-mobile a try which was fast in the hotspot test kit they sent. I may also be curious to see how the cat18 does with verizon compared to my current br1 mini.

In the location I’m at now the included paddle antennas may work if the cat18 is slightly better than the cat6 (currently getting slightly more consistent pings using the larger antennas on the BR1 mini), but in a second location I require the yagis to get a connection at all on the BR1 mini. I was curious if I could test the cat18 there with the 2 yagi antennas that are currently there or if I would need an additional two yagi antennas. I wonder if I have only two yagis there if the cat18 will perform the same / better / worse than the br1 mini using those two antennas.

(also trying not to order much right now to keep as much as possible for those who really need to get something so will probably wait a couple months to order additional antennas.)

I see.

Judging by this post (Max Transit Cat18 - #5 by mldowling) it looks like you may need to have all antenna ports connected.

Did the device come with 2 or 4 antennas?

I don’t know yet – arrives on Friday.
I ordered the MAX-TST-GLTE-G-T-PRM

@tf2287 and @aquablue

Please check the product info using the following URL :

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I appreciate the link to the product page, but I’m unable to find the answers to my specific questions there:
1.) what is the max upload speed (what is the max cell upload speed this device has achieved?)
—edit: I found it on the pdf at the bottom the product page you linked above – thank you!
Router Throughput: 400 Mbps
LTE-A Pro Downlink/Uplink Datarate: 1.2 Gbps/150 Mbps

2.) does it use multiple antennas to upload as well as download (are the aux antennas used to send data to the tower or only receive data from the tower?)

I guess the answer to my #3 question would be an obvious yes, otherwise it wouldn’t have four antenna ports. I guess the real question is whether there is a way to use less than 4 antennas and what would happen to the performance when doing so, or if there are some locations where not all 4 will be utilized, etc. I was confused as my reseller’s product page for the cat18 modem says 2 antennas are included in the box but it has 4 lte antenna ports.

The product page linked above says:
Package Content (MAX Transit)

  • MAX Transit
  • 12V2A Power Supply (ACW-601)
  • 2x 5dBi Wi-Fi Antennas (ACW-341)
  • 1x GPS Active Antenna (ACW-232)
  • 2x 2dBi 4G LTE Antennas (4G LTE)
  • 1 Pair of Mounting Brackets (ACW-724)

Package Content (MAX Transit Duo)

  • MAX Transit Duo
  • 12V2A Power Supply (ACW-601)
  • 2x 5dBi Wi-Fi Antennas (ACW-341)
  • 1x GPS Active Antenna (ACW-232)
  • 4x 2dBi 4G LTE Antennas (4G LTE)
  • 1 Pair of Mounting Brackets (ACW-724)

but I’m not seeing a separate item listing in the box for the MAX-TST-GLTE-G-T which I ordered. The photo calls out 4 cell antenna ports, so I’m assuming that there will be 4 cell antennas in the box… If it doesn’t have all antennas connected, will it fall back to an LTE-A mode and perform like the Cat-6 / Cat-12 versions, or will it perform worse because the Cat-18 needs all 4 antennas to work?

So I received my Transit Max Cat 18 on Tuesday and I’m going to try and answer some of your questions.

Yes, It does come with 4 small antennas that gave me about 2db less signal than my old high end wideband paddle antennas - proxicast/Mofi

The modem in the Cat 18 doesn’t use all 4 antennas in my case because my towers evidentially don’t have 4x4 enabled, but more on that later. For now, here’s why in a picture…


To be continued because new users can only post one picture :slight_smile:

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My choices are…

T-Mobile with B2 at 10mhz, B66 at 10mhz, non-contiguous B66 at 10mhz, and B12 at 5mhz.

AT&T with B2 at 15mhz, B4 at 15mhz, B5 at 10mhz, B30 at 10mhz, B12 at 5mhz.

So then using this chart I’ve underlined my possible combinations color coded by carrier…

Theoretically I should get 270.8down and 37.5up based on the modem using 66, 66, and 2 at 2x2 mimo in my case. Well shy of the gigabit speed I’d hoped for…

So real world on T-Mobile I’m seeing a more stable connection to the towers because it’s always talking on 3 frequencies every time I query the device. I’m seeing 20-40 down and 10up during the day and 100-130down 10-18up at night. I’ve ordered a new AT&T line of service that comes tomorrow and I think I’ll have better luck there based on my research. Hope all this helps!


Extremely helpful – thank you. I have a t-mobile SIM coming tomorrow and the towers near me support 4*, 12, 66, 71.

If I read the above correctly, it looks like the antenna on Primary RF Antenna #1 and Secondary RF antenna #1 don’t support any of those 4 bands, so it won’t make a difference if I connect those until the tower has more bands added. I have two large proxicast omni antennas that have worked well for me and two yagi antennas to test with, but not 4 like external antennas; reseller got back to me and said that there will be 4 small paddle LTE antennas in the box.)

My MAX-TST-GLTE-G-T-PRM arrived today.

First try with 4 included LTE antennas:

Max Transit Cat 18 : 20.8 download 6.9 upload

Coolpad Surf in same location (free with tmobile test kit, no external antenna ports) : 19.1 download 7.3 upload

I was expecting I’d get LTE-A but so far the Max Transit Cat18 is only showing LTE

(this is my first experience with t-mobile; I only had the coolpad surf test device and that device doesn’t show band stats, so it may be that the tower has 4 12 66 but doesn’t do LTE-A?)

Edit: it got LTE-A and showed Band 12 700 mhz and Band 66 but speed was about half of when it connects on band 66 alone; each time after a few minutes it goes from LTE-A back to LTE alone. Will test again tomorrow.

Question: to confirm
Primary RF antenna #0 supporting B4 B12 B66 B71 = Main 1A labeled on the device
Secondary RF antenna #0 supporting B4 B12 B66 B71 = Aux 1B labeled on the device (is this correct? (not Aux 1A?)

I have my 2x2 mimo antenna plugged into the 2 outer connectors. My understanding is the outer connections are one set and the inner connections are another set. Makes sense that they set the primary mimo as far apart as possible when designing it, since you want uncorrelated signals.

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Thanks! Will do more testing tomorrow, but wanted to make sure I wasn’t connecting one of the two yagis to the wrong antenna port.


I did some further testing tonight and found the documentation above to be slightly wrong. The ports across the back, left to right as 1,2,3,4… 1 and 3 are primary and 2 and 4 are secondary. I confirmed this when measuring individual antenna feeds. I unplugged all 4 to measure each feed individually and after you measure in port 1, you can put it in port 3 and get the same measurement, in port 4 you get nothing. So port 1 and 3 are Mimo’ed together. That also confirms I’m in 2x2 mode since the other port yields no measurement. Hope this helps!

Should read…
Primary 0, Primary 1, Secondary 0, Secondary 1


Here’s where my Cat 18 settled on both T-Mobile and AT&T. I had some problems with bandlocks on Both carriers, it seemed like the modem would get stuck and I’d change the band lock and change again and it would unstick, seems like there’s some sort of bug there. I’m seeing much higher speeds on the AT&T side. The T-Mobile tower is definitely more congested.

Good read about the modem here…

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Do you think you can open a support ticket for support team to check ?


Interestingly with t-mobile, I can often get an LTE-A connection on band 12 primary + 66 secondary, but oddly, the upload speed is slower than when it has an LTE connection on band 66 alone (it’s about 1/2 to 1/3 the speed upload when in LTE-A mode with band 12 or when I lock it to band 12 alone compared to band 66 alone. It seems to also drop out of LTE-A into LTE mode every few minutes.)

So for now I’m keeping it on band 66 alone. Will recheck periodically to see if anything changes with the tower I’m connected to. It’s performing very well on the single band right now though.

@aquablue: Yup. You are not alone. Sadly, it seems that “tuning” is often required. Actually, in the environments in which we usually work it’s the norm rather than the exception. “Some fiddling required.” :neutral_face: LTEA is nice – in certain locations.

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@aquablue You are experiencing the issue where you need to know the bandwidth of each band. The modem currently uses aggregation in the download, but only the primary band in the upload. So for me, my towers have 5mhz, 10mhz and 15mhz frequencies… sadly, I don’t have access to a single 20mhz frequency, which is what the theoretical max speeds are based off of… lol. Here’s the Theory based max upload speeds… Again Theory… so a little more than half is possible in real world…

5Mhz = 18.75Mbps (this is my B12)
10Mhz = 37.5Mbps (B2,B4,B66 on T-Mobile for me, B30,B5 AT&T)
15Mhz = 56.25Mbps (B2,B4,B66 on AT&T for me)

Here’s the tool you can use… 4G/LTE Throughput Calculator - Cellular Coverage and Tower Map