I just arrived in San Francisco, CA for Google I/O, which we'll be covering live tomorrow, providing the event's 5 GHz WiFi and backup Verizon LTE or AT&T LTE don't go down. There was much talk a few weeks ago about how T-Mobile had lit up some 1900 MHz WCDMA in time for WWDC and other events, and although I saw a few tech press members post speedtests, we never saw any FieldTest output showing exactly where ol' Magenta is running their 1900 MHz WCDMA.

I just headed over to pick up my badge and couldn't resist the temptation to bring along my unlocked iPhone 4S (how uncouth) with a T-Mobile SIM inside, alongside a pocket full of SGS3s. Anyhow, T-Mobile's PCS 1900MHz WCDMA network was still up inside Moscone Center, and on the sidewalk in front. Coverage is extremely localized however, walk even a hundred feet away from the event center and you'll be dumped back on EDGE 1900 MHz instead of T-Mobile's HSPA+. I managed to run three tests and some FieldTest screenshots. As a reminder, the iPhone 4S is just a Category 10, HSDPA 14.4 device, and results are pretty good for what's likely an unloaded single carrier. 

FieldTest shows a DL UARFCN of 612, which corresponds to 1972.5 MHz and UL UARFCN of 212 at 1892.5 MHz. Andrew Shephard (@wiwavelength) beat me to analysis of which PCS block this corresponds to, and tweeted that this is F block PCS. Well, that finally satisfies my curiosity about T-Mobile WCDMA on 1900 MHz for the most part, at least in this region.