move Home Internet SIM to personal router with external antenna

When I was deciding on a home internet solution 6 months ago, I inquired at the TM store about using my own router because I thought I might need an external antenna and the TM router didn't have a port for one.  At the time Nextgear sold a 4G router that supported an external antenna and was claimed to be compatible with T Mobile.  The rep at the store wasn't sure if it would work,but was willing for me to "try a SIM card for an iPad".  I ended up not doing that, and just went with TM's own hardware (signal reception ended up being quite good)….but it sounded like if you want to use your own router there may be restrictions on how the SIM card is configured.

@syaoran is correct, I experienced the same construct trying my SIM card in another router and internet access to T-Mobiles internet was a no-go. 

I'm working on this right now. Here is what I have figured out so far. I am not able to swap my SIM from the T-Mobile home internet gateway to my own device. It does not work. I also contacted T-Mobile support and they will not register a different device for you. However, you can get T-Mobile business internet and they will allow you to use your own device. It's $50/mo for unlimited Business instead of $30/mo for Home. You'll need a business account to do that. What I have been using for over 4 years is a T-Mobile ipad data plan. That SIM is $20/mo as an addon to my existing T-Mobile phone service and I moved it to my router and it works fine. It gets throttled when you go over 50GB but you can bypass the throttling by setting the TTL to Linux2-65 on your router. You'll need a router like an Insty Connect or MoFi that has the option to set the TTL and there are videos that explain how that works. I was hoping I could switch from $20/mo to $30/mo and have true unlimited data but you just can't do it with your own device unless you go with the business account for $50/mo. 

An EE buddy of mine "speculated" that the reason the routers may not have antenna ports is because the FCC sets transmission power limits, and an external antenna may put you over the legal limit.  Sounds plausible, but I don't really know.

A follow-up. I confirmed that you cannot use a home internet SIM in a different router. T-Mobile will not allow it. It can be done with a business account. I went to a T-Mobile store and one other item I discovered is that if you have 2 lines you can add a third line for a Magenta Tablet plan. It is $20/mo for unlimited data after the discounts and autopay. I also compared the home internet speed with the speed of this new line and they are virtually identical. So if you add the magenta tablet plan you can put the SIM in your router and accomplish the same as the $30/mo home internet option. I'll play with this to confirm it does not throttle. They told me it is a true unlimited plan at the store so we will see.

jasonsele wrote:

A follow-up. I confirmed that you cannot use a home internet SIM in a different router. T-Mobile will not allow it. It can be done with a business account.

Something similar going on at Reddit.

https://www.reddit.com/r/tmobileisp/comments/14dbz1o/new_x62_modem_in_3rd_party_gateway_during_peak

jasonsele wrote:

I'm working on this right now. Here is what I have figured out so far. I am not able to swap my SIM from the T-Mobile home internet gateway to my own device. It does not work. I also contacted T-Mobile support and they will not register a different device for you. However, you can get T-Mobile business internet and they will allow you to use your own device. It's $50/mo for unlimited Business instead of $30/mo for Home. You'll need a business account to do that. What I have been using for over 4 years is a T-Mobile ipad data plan. That SIM is $20/mo as an addon to my existing T-Mobile phone service and I moved it to my router and it works fine. It gets throttled when you go over 50GB but you can bypass the throttling by setting the TTL to Linux2-65 on your router. You'll need a router like an Insty Connect or MoFi that has the option to set the TTL and there are videos that explain how that works. I was hoping I could switch from $20/mo to $30/mo and have true unlimited data but you just can't do it with your own device unless you go with the business account for $50/mo. 

What's the brand and model of your router? I just tried using my extra regular SIM on a Tenda N300 router and it does not work. It will connect to the tower, but no internet to be seen.

Before you purchase a different router/gateway, make sure that you confirm the band compatibility for the EXTERNAL antenna.   Our company purchased the Inseego 5G Wavemaker FX2000 router that IS compatible with multiple cellular providers, with Tmobile being one of them.  The Inseego is compatible with most of Tmobile's broadcast bands, but only with the INTERNAL antennas.   The external antennas only support 3 bands, and NONE of them are used by Tmobile.   

Just thought that information would be helpful.   I am also trying to find a gateway/router that utilizes and external antenna that IS compatible with Tmobile bands.   Any help would be appreciated. 

bocaboy2591 wrote:

I don't think that will work since the SIM is hardcoded to the device (gateway) as well as the location. I'd be surprised if you got this to work, but if you do, please let us know!

Where did you learn about these hardcodings? Because, my experience is somewhat different.

For anyone who might be reading this 9 months later…. the white router has 4 external small form factor coax antennae ports (assuming 2 for wireless and 2 for wifi).

I haven't used them, but I noticed them and, unfortunately, also noticed the mickey mouse UI. Would be nice to be able to change the internal network ip cidr, disable wireless completely and use passwords with spaces, among other things. Seems like a feature across T-Mobile's UX to not understand that spaces actually increase entropy (it's 2023, not 1998). I worked around this by just hooking up my previous router.

Other than those personal gripes, so far so good relative to cable (surprised at how well it handles gaming and heavy file xfers). I'm still in the trial period so hopefully it's not all downhill from here!