I haven't done 195Pt in a while, but I remember it wasn't too bad. One thing to consider is the very big chemical shift range. It can be almost 1 MHz at 11.7T (500 MHz 1H). This can mean a lot of searching if you have no idea where your peaks are. The chemical shifts are also very temperature dependent, about 1 ppm per degree. So, good temperature control is critical if you want narrow lines. Also, if you have to go searching for peaks, remember that your probe may not have that kind of bandwidth. You may have to record the range in portions, re-tuning the probe between regions. You will also need short pulses if you want to excite a wide spectral window. Start with a good standard sample. 1.2 M Na2PtCl6 is what is normally used. This has a IUPAC "chi" value of 21.496 784 MHz. Multiply this by the frequency in MHz of TMS /100 to get the frequency of the reference. On our 500 instrument TMS is exactly 500.13 MHz, so the Pt reference would be 107.511 866 MHz. You should see sample this in ***1 scan*** at 10 mm, maybe a few scans at 5 mm. In liquids, the T1 values are typically 1s or less, so you do not need a huge relaxation delay. Let me know if you are still not having any luck seeing the signal.