The traditional gsm towers (Vodacom & MTN Share it) is at the exchange in Dersley Ext (Opposite Geronimo's & Gym).
I would assume they have used the same premises for the 3g, however, to cover a full gsm cell, they need several 3g towers as the range is shorter.
I know of some grey area around Corundum/Galena and also Albite/Cloverfield.
What roof do you have?? Metal/Harveytile do affect signal.
Traditional metal roofs are mainly from the mining era around here - Between Silica & Orpiment, Shale etc. Epidote on the shop side and a street or 2 below, Dersley ext - last str or 2 on the Eastvale end. Also some in Cloverfield, opposite shops.
Feel free to pm me if you want to try your modem at my place and/or we try mine at yours.. Long shot - modem.
I am just pondering now. Vodacom was off for most of yesterday afternoon here - appr 8hrs. Just noticed my 3g signal is 4 bars. Wondering if they did some upgrading or is it just good weather for the signal - only time or @v3g confirmation will tell.