Arcadyan KVD21 5G which connectors for 5G external antenna

Thanks iTinkeralot. I had been using the recommendations from Nader Tader, but I will try these now and report on the findings. 

Thanks!

Keep in mind to try to improve the SINR and avoid noise. Leverage your home to shield the antenna from unwanted RF if necessary. Improved RSRQ should improve performance. 

Previous user had damaged one as well. He found a local guy that fixed his for $70. The U.Fl connectors can be purchased on Amazon pretty cheap. If you have soldering skills it is fairly simple to fix but means removing the board to do the repair. The man that fixed his also put the antenna dongles on for him. 

Hi all, an update: I moved my antenna in the rafts closer to the T-Mobile n41 cell site and my RSRQ and RSRP got better, but my SINR is horrible. I show 4 bars (almost 5) on my T-Mobile app. 

RSRQ -8

RSRP -86

SINR 4

Question - what can one do to improve the SINR? I am doing google searches for how to improve SINR and alike with negative results. My speeds are not good, which is in large part to my poor SINR ratio. 

Any suggestions much appreciated! 

I can find one Reddit post where the guy is using a 2X2 MIMO antenna with n41 so the 4x4 is maybe not a must have. 

Here is a Ookla screenshot with the Jitter. Geez, If I got these results all the time I wouldn't complain. But, by 8-9 am, downloads will drop to 30-45 Mbps.

If you can get the cellular metrics in more detail understanding just what is going on might help a bit more. The speeds in the history are pretty inconsistent. Do you have the metrics for both the 4G & 5G signals such as the band and the bandwidth in MHz for them? I suspect in some of the cells if the bandwidth is less than 20 MHz and user load/demand is higher that contributes to less bandwidth per user session. Then it is more critical to have a clean signal to prevent packet loss that will result in retransmissions. 
Use cellmapper.net to confirm the locations of other towers/cells in the area as you consider antenna placement in relation to the tower you are using. Here I know there is noise from other RF sources towers the west/northwest. I have my gateway in a window with northeast exposure to get the signal from the tower that is due north just because the signal is cleaner than using the north facing window. Results are better so I know using the house as a shield can help. The other obscure issue can also be with reflected signals. Cellular signals seem to be subject to multiple external factors so it is tricky at times to avoid issues. 

Here is the n41 map, which shows the towers farther north from my location. Is there a definitive way to tell which signal I am receiving or tied to? My T-Mobile app shows I can either be on n41 5G or b66 LTE.

With the speed test results you last posted I agree it would be no problem but I an guessing it is somewhat due to user load and the backhaul routers. The signal noise is probably due to the volume of RF in the area. I would guess if you look for ATT and Verizon towers you would see lots of cells in that area. The noise could be from some type of industrial facility or emergency responder transmissions and such. 
You can set a preferred source vs allowing Speedtest.net to just go out and determine an “optimal” target to use for the testing. Then you have a reference so to speak. If you have not gone into the Ookia advanced settings and set them I suggest you do. The more you see the more you know. Also run fast.com tests as well. Free tools. 

If you haven’t reviewed Waveform’s guide for the T-Mobile Arcadyan gateway you really should. They have a very good guide. 

Regarding n41 and b66. The n41 is the 5G which T-Mobile will leverage for the download flow. The b66 is the 4G LTE and is commonly used for the upload traffic. So you would notice, if you could see it, that the gateway maintains two signals. The primary signal is the 4G LTE signal b66 and the secondary signal will be the 5G signal n41 in your case. The gateway really needs both to work the way they intend it to work. It is NOT a pure 5G solution with T-Mobile. 

The link below renders the page that has the bands T-Mobile uses for each signal “type”.

https://www.t-mobile.com/support/coverage/t-mobile-network

You might check out Nater Tater’s YouTube videos on the antenna addition. I am more familiar with the Nokia gateway and the waveform external MIMO antennas. I believe his videos focus on those both 2x2 and 4x4 MIMO. To take full advantage of the n41 mid band frequency a 4x4 MIMO is really needed. I do know Waveform.com has some excellent documentation for the gateway break down and the antenna additions. You might have to experiment with the connections a bit if it is not clearly documented in a way that makes sense for that antenna. One thing to be extra, extra careful about is making the connections to those u.fl connectors. They are tiny, delicate and easy to break. If you break one they are not too difficult to replace but just need the tools and the connectors which also can be bought online. 

Without any documentation I can’t say which connections to make. I believe Nate has also covered the Sagemcon as well as the Arcadyan gateways. The Nokia he went over before those. The information from Waveform is excellent.