Any cell routers with external antennas?

I have a KVD21 with firmware 1.00.18. In the first week I got it, the performance is extremely inconsistent. I sometimes got single digit up and down, but also triple digit down and single digit up in a good day. It was  very random but generally very bad during the day, better later in the night. It was unacceptable. Then I bought a Waveform 4x4 panel antenna. Since then, the performance has stablized. I generally get at least 100 down and 20 up during the day and 180 down and 30 up during the evening. The ping numbers are also greatly improved, always sub 20 ms without load and 300ish ms under load.  I am not even putting the antenna outdoors.  I put it right on the desk, next to KVD21, facing the direction of the tower through a glass window.  The tower is about 1 miles away without line of sight.

I also tested the antenna outside. I could get 400 mbps. But the trouble to install the antenna outside is way too much for me. 

The performance has been rock solid for two weeks. 

I too have the Arcadyan KVD21 5G gateway and I'm surprised that they didn't include a port for an external antenna. You might want to check out Nater Tater on YouTube who has tutorials on how to crack open the KVD21 and attach an external antenna. It's definitely not for the faint-of-heart, but for how, it's the only hack I know of for this device.

While I don't live in a pine forest, I live in a heavily treed community where the trees form a tunnel over the entire roadway. It adds to the challenge of getting a good signal from T-Mobile for my home Internet. I've only had the gateway for two months, and I'm satisfied with the bandwidth I'm getting, somewhere between 35-70 Mbps, and only on 4G LTE. Nonetheless, it's more reliable than Xfinity and definitely less expensive.

One last thought: I have read a lot of threads on this forum of people who started out great with T-Mobile for a year or so, only to watch their service go downhill from there. I'm not sure what happens, but it appears it's not uncommon to go from great service down to unacceptable.

What I did to help resolve the problem  The outside Bucket.

A few questions first:

1. about how far are you from you cell tower?
2. Is it line of sight or obstructed by buildings, trees, etc.?
3. Did you try using the placement function on the mobilize app? (Trying to improve your scores)
4. Did you try rotating your gateway to find the best antenna position for your situation? 

Try a few of these suggestions then let us know your results.

I am about 1.5 miles from one tower and 2.0 miles from another. Not line of sight, I live in a heavy pine forest with hilly terrain. I spent over 4 hours trying different locations:through upper story windows, using buildings as shields and walking around 2 acres. I have found the only location that will lock onto a signal though the SINR never gets much above +3. It is looking down a tree lined street, so I need a weatherproof gateway with external antennas. So I ask again- does anyone have experience with exterior rated weatherproof MIMO routers, or is this not an option for T-Mobile?

I have had the gateway for over 6 months now. It worked great at first. We had 5 phones, 3 tvs, and 2 xboxs and we were getting 60-100mbps on downloads. Over the past month it has gotten so bad that now if we disconnect everything except 1 device, my phone can't load a webpage, my Xbox will get about 100kbps and tvs time out just trying to load the Netflix app. I have reset the box, I have moved it to every window in the house, nothing helps. I am about to just return it since regular service on my phone with a phone hotspot turned on is faster than the wifi. I'm done paying $50 a month for something that is slower than 1 bar of 4g on my phone. I was impressed at first but now I'm irritated. 

Captzoomie, I was going to suggest you view johnbor's setup, using a bucket outside, which shields the gateway from the weather elements, but does not block the signal. Maybe you can do something similar? 

Actually, that's exactly the setup I have, except mine is mounted on a shelf on top of a fence post! That has been my set up for 2 weeks. However, that still gives me an average of 2 M down, 0.5 M up, with intermittent outages thru the day, higher speeds at night. I need to improve from my current setup, especially uplink speed. Bocaboy - glad to hear yours is working, and I am also concerned about good service at initiation, followed by poor service thereafter. Please keep us up to date on what happens in your situation. Interesting that you are stable with only a 4G signal... perhaps there's some hope for my case. ¡Gracias!

Check you app for the firmware.  It is probably 1.00.18 and if you look at Advanced Cellular Metrics, you see LTE is connected but 5G is not.  Happening to a bunch of us here… what was 100mbps down is now 1-10mbps.  TMO claims it is a tower issue even though that's the only device that is not able to connect to 5G.

Litewavve, how did you connect the Waveform antenna to the KVD21 gateway? Also, can you include a link to Amazon (or any other supplier where you bought this antenna) so we can be sure we're getting the correct unit.

¡Gracias!