Signal source
FCC filing signals.
Products with a radio sold in the United States are filed with the FCC. The filing is public and often includes internal photographs of the boards, a user manual, and sometimes a block diagram.
It is one of the few public places where a manufacturer's own documentation shows what is on the board.
A specific device, on a specific board, on a date.
An internal photograph with a legible marking, or a manual that names a device, is direct evidence. In testing, filings surfaced products with a named programmable device, including a hardware manual that named the exact part.
- Device family and often the exact part number
- Board revision at the time of filing
- The filing date, which bounds how old the design is
Coverage is narrow and the record is a snapshot.
Only products with an intentional radio are filed, so a wired industrial camera or a motor controller usually is not. Manufacturers can request confidentiality for internal photos and schematics, and many do.
A filing shows the board that was certified. A later revision can change a device without a new filing if the radio section is unchanged. The filing date is recorded with the evidence for that reason.
Filing databases are indexed by grantee and product code. Product codes sometimes coincide with part family names, so a search for a family name returns unrelated products. Results are screened before they count.
Where filings help most.
- Wireless and connected products in an application class
- Confirming a device seen in a teardown
- Dating a design
How signals are detected · Teardown signals · Datasheet signals · Job posting signals
Ask what filings exist for your target products