3G Mifi MIMO external antenna

[anthdci]

I am not sure if this is in the correct area so I am happy for it to be moved if needs be.

 

I have a Huawei E5776 Mifi device in the UK, I use it with the sim card from my iPad Mini which is a 4G contract. It only gets used when I am off the grid in my caravan, this basically means I am nowhere near mains electric and have to run everything off either my 12v leisure battery, or some other battery source.

 

The reason I use the MiFi is because it can share the 3G/4G connection with more devices easily and it can take an external antenna which the iPad cannot. There are a couple of sites that are very much on the edge of cellular coverage that I often visit. Enough for a normal device to pick up but not enough to give a reliable connection. I have been doing some research about and I have found out that if I want to use LTE, I need to use either the devices own antennas, or use TWO external antenna inputs, this is for the MIMO aspect of LTE. My e5776 only has 1 external port so that means I will be limited to 3G. I am quite happy for this to be honest, it is still plenty fast enough for my basic use. As it is I have one of these 

http://www.ebay.co.uk/itm/400755912405?_trksid=p2060778.m1438.l2649&var=670300250615&ssPageName=STRK%3AMEBIDX%3AIT

it has 2 SMA connectors which I have a joint connection for then a SMA to TS9 connection which means both the vertical and horizontal antenna inside it get passed to the 3G part of the MiFi. That seemed to work fine in the venue I tested it at in September, but in that venue the signal was just about usable, with this setup it was strong enough to get about 3-5mb/s which I was happy about.

 

I am now considering an upgrade. Next year I will go back to a few venues that I know I really struggle for signal, again they are pretty much on the edge of the mast's range. I don't want to turn up at these venues only for the setup to fail, especially when I will have friends and family around who know what I am up to.

 

So my thinking is getting another identical antenna since they aren't expensive. Then getting a couple of SMA joiners and have 2 antennas at opposite corners of the caravan roof each with 2 antennas inside being combined, then going to the MiFi.

 

Has anyone got any experience with this. Should I be concerned about having an extension cable attached to one, or will this introduce a split second latency so the signal isn't identical coming into both antennas? Will having the second antenna make much if any difference? Cost isn't really an issue when the antenna is ?11, the SMA joints are 99p each and the SMA extension is ?3 so I am thinking it is worth a go anyway.