Newer modems like the K4505 (aka Huawei E1820), K4605 (aka Huawei E372) and Huawei E367 have two antennae on the modem, but only one external antenna connector. The external antenna connector seems to switch out one of the modem's antennae, the primary antenna in the case of the E372 and E367 and the secondary antenna in the case of the E1820.
Sometime in early December 2011, the negotiated QoS values returned by my modem from my closest Vodacom tower changed from 16000/8640 to 21000/5760 on an E1820 and 42000/5760 on a K4605. I hoped that this meant my tower had been upgraded to 42Mbps DC-HSDPA, but to date have not seen a speed test result above 21Mbps, which I think would be clear evidence thereof.
Having had some success using a Wilkinson power divider (or splitter) with an E1820 on Cell-C's network, I wondered whether this could be used to improve speeds by presenting a strong signal at both the modem's external antenna connector and the unswitched antenna on the modem using an inductive coupler.
I have an existing LPDA-A0044 antenna aimed at my closest Vodacom tower, Poynting Direct loaned me a SPLT-A0014 2-way splitter and ADPT-026 inductive coupler, which I connected together with a CAB-038 pigtail to a K4605 modem.
Antenna Connection Ping (ms) Download (Mbps) Upload (Mbps) Cell ID RSSI (dBm) Link CAB-038 78 13.7 1.55 64351 -55 1 CAB-038 91 7.06 1.49 64351 -55 1 CAB-038 88 10.27 1.44 64351 -55 1 CAB-038 & ADPT-026 96 17.78 1.45 64356 -59 1 CAB-038 & ADPT-026 90 12.63 1.70 63256 -59 1 CAB-038 & ADPT-026 73 12.23 1.43 64356 -59 1 CAB-038 92 14.85 1.63 64351 -55 1 CAB-038 89 14.02 1.42 64351 -55 1 CAB-038 89 12 1.57 64351 -55 1 CAB-038 & ADPT-026 95 13.4 1.63 64351 -61 1 CAB-038 & ADPT-026 79 13.24 1.53 64351 -61 1 CAB-038 & ADPT-026 87 13.89 1.45 64351 -61 1
Antenna Connection Ping (ms) Download (Mbps) Upload (Mbps) CAB-038 88 11.98 1.52 CAB-038 & ADPT-026 87 13.86 1.53
I was disappointed by the results, I was really hoping to see the speeds almost doubling.
Perhaps this is just means my tower has not yet been upgraded.
I also noticed my upload speeds were half the speed they had been previously.
Shortly before I got those results, I had a Vodacom technician at my house investigating an unrelated problem. While doing speed tests, he commented that my upload results were poor and that he would have the site reset, this made a noticeable difference, but seems to have been short lived.