SXT LTE6 grounded antenna. Should it be?

Hardware MikroTik hardware general
1

I have SXT LTE6 bought secondhand. I have been trying to set it up. I’m in the UK and have tried SIM cards from Three and Lebara (Vodafone).

Despite trying it pointing in all directions in several different locations I can’t get an RSSI or better than -111 Db with a best recorded download speed of 0.04 Mbps. The Three mast is about 700m away, Vodafone slightly further away. I can get 80 Mbps down with my phone from the Three mast. I have manage to update RouterOS but trying to update the modem firmware has failed every time.

I started to wonder if the internal antenna were connected to the modem at all so opened it up and checked. They are. However, I did notice that there was continuity between the board ground screw and the two “F” antenna, and also with the rearmost central plate antenna element. Effectively all the antenna appear to be grounded.

Is this correct?

TIA

2

A bit of research into antenna theory suggests that the antenna should indeed be shorted to ground in order to work.

3

Thanks for the heads-up. I didn’t know an antenna should be grounded. I’ve been using SXT LTE Kit without ground for months. Current RSSI is -51 dBm on a 3G SIM with speeds varying throughout the day (probably depending on the traffic). Anyway, I am going to try to ground the antenna to check if it improves the reception.