The turnover frequency mapping procedure (Lobanov 1998b) was applied to the multi-frequency VLBA observation of 3C273 made on November 17, 1994. The source was observed at 5 15.4, and 22.2GHz. At each frequency, there was roughly one 5 minute scan made every 20 minutes. After the correlation, the data were fringe-fitted and mapped in AIPS and DIFMAP. The turnover frequency map produced from the VLBA maps is shown in Figure 1. (Lobanov et al. 1997)