The router is Top but crucial is the stick used

I've bought from Amazon, the recommended in this router set of routers, Huawei E176 and 10 db external antenna. The system worked immediately. The router has detected the drive spaces and the installation is very simple.
I have 3 sticks to the router tried because I am disappointed with the reception power to the E176 despite external antenna. I have previously downloaded the latest firmware on the router, as a slightly older version was loaded onto the router.

- The newly appointed Huawei E176 with and without an external antenna (10 db antenna)
- A Huawei E173 (without antenna socket)
- A Huawei E1750 (without antenna socket)

When SIM card is a used by O2. All 3 sticks were recognized by the router easily and sticks all have basically functioning. However Absolutely disappointed I am by E176. By then, of course, and even without an external antenna This stick has the worst reception. By far the E1750 has the best result brought even if he does not allow connection of an external antenna.

An indication yet. I can not explain why, but the E1750 could be used in my experiments with a USB cable extension for the stick to me. All other I had directly into the USB jack plug on the router, otherwise was nothing (was not even recognized).