Download of rfInvestigator 2.10 was on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The following version: 2.1 is the most frequently downloaded one by the program users.
RfInvestigator is included in Internet & Network Tools. The program's installer is commonly called rfInv2_10.exe, rfInv3_5.exe, rfInv3_6.exe, rfInv3_7.exe or rfInv3_8.exe etc. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. This software was originally produced by rfSoftware, Inc.
From the developer:
rfInvestigator-FM is an engineering tool to help you comply with FCC 73.207, 73.215 and 73.509 rules when applying for a new FM broadcast station or making changes to an existing one. The program performs both spacing and contour analyses and allows you to search it's database of FM stations and applications.
This program offers a host of advanced features, many of which are not found in similar programs or are offered as expensive additions.
You may want to check out more software, such as NI-488.2 for Windows, South African Airways Timetable or MBCFX, which might be similar to rfInvestigator.