Formulas & Data:
- Electronics
- Mathematics
- Physics
- RF & Microwaves

Parts Vendors:
- all hand-selected

- Amateur Radio
- Vintage Articles:
- Electronics World
- Popular Electronics
- Radio & TV News
- Radio Craft
- Short Wave Craft
- Wireless World

- Events Calendar
RF Cafe Homepage
Copyright 1999-2015   •−•  ••−•    −•−•  •−  ••−•  •   "RF Cafe" in Morse Code  >> Listen to It <<
- EW & Radar Handbook
- Quizzes       - Software
- App Notes
- Calculators
- Advertise on RF Cafe
- About RF Cafe™
- RF Cafe Shirts & Mugs
- RF Cafe Archives
RF Cafe Book Contest
- RF Cafe on Visit RF Cafe on Facebook Visit RF Cafe on Twitter Visit RF Cafe on LinkedIn
- Tech Humor
- Forums Archive
- Job Board
- Donate to RF Cafe
- Kirt's Cogitations
Custom Search
More than 10,000 searchable pages indexed.
Greetings: There is so much good stuff on RF Cafe that there is no way to list or link to all of it here. Please use the Search box or the Site Map to find what you want - there is a good chance I have it here. Thanks!

FCC Part 15 Radio Frequency Devices
Section 15.121

The Federal Communications Commission (FCC) is the authority in the United States of America that creates and enforces the use of airwaves throughout the entire radio frequency spectrum. This group of documents contains the entirety of the FCC Part 15 regulations that concern unlicensed radio frequency devices. As with all government documents, this material is in the public domain and may be freely copied so long as the content is not changed. This copy is provided as a convenience for RF Cafe visitors. 

Click here for the Table of Contents.

[Code of Federal Regulations]
[Title 47, Volume 1]
[Revised as of October 1, 2008]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR15.121]
[Page 789-790]
                       TITLE 47--TELECOMMUNICATION
                    Subpart B_Unintentional Radiators
Sec. 15.121  Scanning receivers and frequency converters used with scanning receivers.
    (a) Except as provided in paragraph (c) of this section, scanning 
receivers and frequency converters designed or marketed for use with 
scanning receivers, shall:
    (1) Be incapable of operating (tuning), or readily being altered by 
the user to operate, within the frequency bands allocated to the 
Cellular Radiotelephone Service in part 22 of this chapter (cellular 
telephone bands). Scanning receivers capable of ``readily being altered 
by the user'' include, but are not limited to, those for which the 
ability to receive transmissions in the cellular telephone bands can be 
added by clipping the leads of, or installing, a simple component such 
as a diode, resistor or jumper wire; replacing a plug-in semiconductor 
chip; or programming a semiconductor chip using special access codes or 
an external device, such as a personal computer. Scanning receivers, and 
frequency converters designed for use with scanning receivers, also 
shall be incapable of converting digital cellular communication 
transmissions to analog voice audio.
    (2) Be designed so that the tuning, control and filtering circuitry 
is inaccessible. The design must be such that any attempts to modify the 
equipment to receive transmissions from the Cellular Radiotelephone 
Service likely will render the receiver inoperable.
    (b) Except as provided in paragraph (c) of this section, scanning 
receivers shall reject any signals from the Cellular Radiotelephone 
Service frequency bands that are 38 dB or lower based upon a 12 dB SINAD 
measurement, which is considered the threshold where a signal can be 
clearly discerned from any interference that may be present.
    (c) Scanning receivers and frequency converters designed or marketed 
for use with scanning receivers, are not subject to the requirements of 
paragraphs (a) and (b) of this section provided that they are 
manufactured exclusively for, and marketed exclusively to, entities 
described in 18 U.S.C. 2512(2), or are marketed exclusively as test 
equipment pursuant to Sec. 15.3(dd).
    (d) Modification of a scanning receiver to receive transmissions 
from Cellular Radiotelephone Service frequency bands will be considered 
to constitute manufacture of such equipment. This includes any 
individual, individuals, entity or organization that modifies one or 
more scanners. Any modification to a scanning receiver to receive 
transmissions from the Cellular Radiotelephone Service frequency bands 
voids the certification of the scanning receiver, regardless of the date 
of manufacture of the original unit. In addition, the provisions of 
Sec. 15.23 shall not be interpreted as permitting modification of a 
scanning receiver to receiver Cellular Radiotelephone Service 
(e) Scanning receivers and frequency converters designed for use 
with scanning receivers shall not be assembled from kits or marketed in 
kit form unless they comply with the requirements in paragraph (a) 
through (c) of this section.
    (f) Scanning receivers shall have a label permanently affixed to the 
product, and this label shall be readily visible to the purchaser at the 
time of purchase. The label shall read as follows: WARNING: MODIFICATION 
    (1) ``Permanently affixed'' means that the label is etched, 
engraved, stamped, silkscreened, indelible printed or otherwise 
permanently marked on a permanently attached part of the equipment or on 
a nameplate of metal, plastic or other material fastened to
[[Page 790]]
the equipment by welding, riveting, or permanent adhesive. The label 
shall be designed to last the expected lifetime of the equipment in the 
environment in which the equipment may be operated and must not be 
readily detachable. The label shall not be a stick-on, paper label.
    (2) When the device is so small that it is not practicable to place 
the warning label on it, the information required by this paragraph 
shall be placed in a prominent location in the instruction manual or 
pamphlet supplied to the user and shall also be placed on the container 
in which the device is marketed. However, the FCC identifier must be 
displayed on the device.
[64 FR 22561, Apr. 27, 1999, as amended at 66 FR 32582, June 15, 2001]

Your RF Cafe
Progenitor & Webmaster

Click here to read about RF CafeKirt Blattenberger… single-handedly redefining what an engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem!
(Seize the Day!)

5th MOB: My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website