Yes, as I mentioned I have experience hoisting a data card, using different lengths of active and passive USB cables and connecting external antennas to the data card (OK, I didn't mention that last one). Here is my experience:
1. Hoisting the card works better if you don't have a line of sight to a cell tower where you normally use the card or if your boat environment
blocks or attenuates the cell signal.
2. You can get by with a 5 meter USB cable. Active ones may work better than passive ones. If the signals are weak or marginal, you may experience timing problems and have a lot of dropped connections with a 5 meter cable. You will definitely experience these problems with two active 5 meter cables connected, even in stronger signal areas. You will fail almost always with three active 5 meter cables. You will also fail with a single
active 10 meter cable. The problem isn't loss of signal in the USB cable, it is in the precise timing that the cell system needs in the communication protocol.
3. Connecting an external 6db gain antenna, specifically designed for the cell frequency you will be using (depends on the provider and area) helps tremendously. An external antenna inside the boat will beat the data card outside the boat, and will be altogether another step up outside the boat. You will still experience problems using long USB cables because of the timing issue.
The mifi units cost more, but aren't outrageously expensive. Ours cost $139 USD (unlocked, Amazon). You can find others for a bit less, but not much. They provide a lot more options over a simple USB dongle - foremost is the ability to put them anywhere you want to get a signal - including at the top of the mast. A decent wifi
system costs the same or more.
As with wifi (they work on the same frequency band), coax is a killer and receive sensitivity is everything. If you stuck an antenna up high and connected with a run of coax to the cabin
, it won't matter how much you heat the air around you with an amplifier, you just aren't going to hear anything. Even with a bidirectional, you are wasting a lot of energy just to overcome the coax loss. That type of system will not be better or cheaper than a mifi with external antenna in the same location.
will have cell access anywhere there is a cell tower. That would include at least parts
of the out islands with possible dark zones between towers.