Help with t-mobile connecting issue on EM7565

[catchsm0k3]

I have an archer c7 flashed with r00ter with a EM7565 connected to it via USB.

Works without an issue with an unlimited Verizon sim card but when I connect it to T-mobile, also an unlimited prepaid card it starts to have issues.

I prefer the T-mobile sim card because it gets better speeds on band 66 but for some reason, it keeps connecting and disconnecting from service.

I also have a 7455 modem that does not get band 66 but works flawlessly with t-mobile just slower speeds.

Anyone has any idea on why t-mobile on the EM7565 would have issues staying connected to a r00ter router? I'll attach some screenshots from the at! command terminal

[catchsm0k3]

The at!gstatus? when it's trying to connect, running on generic firmware

during timeout.png

The connection/cell information once connected

once connected.png

Another thought, when I connect Verizon to the same modem 7565, it does not stay just on band 66 but connects to
B13 (Bandwidth 10 MHz) aggregated with:
B66 (Bandwidth unknown)

so is it possible the issue is with band 66 itself?

[shoulin333]

What type of antenna? It does sound like it is having trouble staying connected to band 66 with quality. Your RSRP is -110 which isn’t good

When you switch modems it can’t try to band 66 so it stays connected on a band it can communicate with. What RSRP do you get ok that other band?


For T-Mobile band 66 I have had awesome results with this antenna.

Log Periodic Directional Yagi Antenna 15dbi Gain for 3G 4G LTE XLTE AWS IDEN PCS 698MHz-2700MHz Wide Band Full Band https://www.amazon.com/dp/B075C8FX3S/re ... gFbT789P1K

[Didneywhorl]

RRC Idle tends to mean you have an issue registering to the network.

Are you using ipv4 and ipv6 TTL settings? I think Tmo likes IPV6 TTL on devices capable of ipv6

[catchsm0k3]

What type of antenna? It does sound like it is having trouble staying connected to band 66 with quality. Your RSRP is -110 which isn’t good

When you switch modems it can’t try to band 66 so it stays connected on a band it can communicate with. What RSRP do you get ok that other band?


For T-Mobile band 66 I have had awesome results with this antenna.

Log Periodic Directional Yagi Antenna 15dbi Gain for 3G 4G LTE XLTE AWS IDEN PCS 698MHz-2700MHz Wide Band Full Band https://www.amazon.com/dp/B075C8FX3S/re ... gFbT789P1K

I am using the antennas that come standard with the cba850, nothing external yet.

I did plan on buying an external antenna this week and trying to mount it on a mast on my roof soon.

[catchsm0k3]

RRC Idle tends to mean you have an issue registering to the network.

Are you using ipv4 and ipv6 TTL settings? I think Tmo likes IPV6 TTL on devices capable of ipv6

I have the TTL set to 64 for T-mobile but haven’t touched any of the IPV4/6 settings since I’m unfamiliar with them.

Using whatever comes standard out of r00ter. I’ve read people say to disable IPV6 though

[catchsm0k3]

What type of antenna? It does sound like it is having trouble staying connected to band 66 with quality. Your RSRP is -110 which isn’t good

When you switch modems it can’t try to band 66 so it stays connected on a band it can communicate with. What RSRP do you get ok that other band?


For T-Mobile band 66 I have had awesome results with this antenna.

Log Periodic Directional Yagi Antenna 15dbi Gain for 3G 4G LTE XLTE AWS IDEN PCS 698MHz-2700MHz Wide Band Full Band https://www.amazon.com/dp/B075C8FX3S/re ... gFbT789P1K

Hey! Follow up question, does that antenna you link need any additional adaptors to connect to the em7565 modem?

Do you have two more mimo or just one?

[shoulin333]

Yes you would like to do this...

FME (antenna connection)
--> N Female (cable)
--> N to SMA adapter (you could achieve this a couple different ways, lots of options)
--> MHF4 (https://thewirelesshaven.com/shop/cables/pigtail- ... er-cables/)


For me with T-mobile MIMO didn't give me anything extra, I did try it though.