HIDDEN RADIO-TV FREQUENCIES
You have your scanner on, and hear music. After a while you realize
that it’s your local radio station. Again that evening you hear yet
another broadcast that sounds like it is on AM or FM radio, but it’s on
your scanner. It’s a high school football game, yet there are no
commercials. What are you listening to?
If your scanner is tuned to frequencies which are used for the
remote broadcast auxiliary service, you have probably found a very interesting
section of VHF and UHF spectrum.
Broadcast Auxiliary Service frequencies are a group of frequencies
which are allocated to radio and television stations for the purpose of
broadcasting news, cuing and correspondence between people in the field,
emergency transmissions, operational instructions, and tests to check
the performance of emergency circuits. The frequencies which are allotted
by the FCC are in groups dependent on their specific use. For example, at
WLIO Television, we have a repeater on 450.61250 which is used for our
news department. That frequency may be used for standard communications,
like the type a police department may use. We use it to cue reporters in the
field, to coordinate the antenna azimuths on the microwave E-N-G,
(Electronic News Gathering), truck, and for tipping off reporters in the field on late breaking news. The frequency of 450.61250 is for voice transmissions, and can not be used for any type of data transmissions nor may it be used for wide bandwidth audio programming. Some other frequencies can. Lets look at these frequencies for radio and television stations.
Group-K frequencies are 152.8700, 152.9300, 152.9900, 153.0500,
153.1100, 153.1700, 153.2300, 153.2900, and 153.3500. These frequencies
are normally used for news operations, and two way communications
between the studio and the site. As these frequencies are shared with other
services, traffic on these frequencies by broadcasters is limited.
Another set of Group-K frequencies are 161.6400, 161.6700, 161.7000,
161.7300, and 161.7600. The most common use of these frequencies are
portable transmitters in the field, sometimes called by their trade name
Marti’s. A sportscaster may used these frequencies to send his play by
play report back to the station. A problem has recent occurred on these
frequencies which is hampering their use. The Canadian government has
licensed transmitters on adjacent channels of these frequencies for a
weather-traffic maritime system on the Great Lakes. Interference has
caused many broadcasters around the Great Lakes to abandon these
frequencies for the UHF band.
Group-L is the frequency of 166.2500, and Group-M is the frequency
of 170.1500. These frequencies are mainly used for two way communications
like the first set of Group-K frequencies. Much of the transmissions are
communication cues from the studio to the remote site.
Group-N(1) frequencies consist of 450.0500, 450.1500, 450.2500,
450.3500, 450.4500, 450.5500, 455.0500, 455.1500, 455.2500, 455.3500,
455.4500, and 455.5500. Most of these frequencies are used for program
transmission like the Group-K frequencies in the 161 band.
Group-N(2) frequencies consist of 450.08750, 450.11250, 450.18750,
450.21250, 450.28750, 450.31250, 450.38750, 450.41250, 450.48750,
450.51250, 450.58750, 450.61250, 455.08750, 455.11250, 455.18750,
455.21250, 455.28750, 455.31250, 455.38750, 455.41250, 455.48750,
455.51250, 455.58750, and 455.61250. The majority of these frequencies
are used for two way conversations between news operations at the
station and the reporters in the field. It is not uncommon to hear some high
power repeaters on these frequencies, like WLIO(TV)’s News repeater. At time
when conditions are good, we have heard other television stations in
Detroit and Chicago.
Group-P frequencies are 450.0100, 450.0200, 450.9800, 450.9900, 455.0100, 455.0200, 455.9800, and 455.9900. These frequencies are mainly
used for data transmissions such as T.S.L.’s, (Transmitter to Studio
Link), or FAX data links. A T.S.L. usually carries data from the AM or FM
transmitter which corresponds to the meter readings. A FAX data link
may be a weather radar system, graphics animation pictures, or digital data
from a remote satellite location.
Group-R frequencies are 450.6500, 450.7000, 450.7500, 450.8000,
450.8500, 455.6500, 455.7000, 455.7500, 455.8000, and 455.8500. These
frequencies are like the Group N(1) channels but they are allowed more
bandwidth for higher fidelity. Additionally, there are 450.9250, and
455.9250. These two frequencies are considered to be “stereo pairs” and
are used for stereophonic broadcasts from the remote site to the
Some interesting notes about these frequencies. In Puerto Rico and the Virgin Islands the frequencies of 160.8900, 160.9500, 160.0100, 161.0700,
161.1300, 161.1900, 161.2500, 161.3100, and 161.3700, are used for
broadcast relay. When conditions are right they are a good catch for DX
as programming can last up to four hours at a time, and obviously music on
your scanner is easy to identify!
Another thing you should be aware of is that in Canada, some of
these frequencies are used in a different fashion. On 450.3500, for example,
this frequency is used by WMTR-FM in Archbold, Ohio, to relay High
School sporting events from the High School to the station as a Remote Pickup.
In Canada, CKLW-AM uses this frequency to transmit their studio programming
from Windsor down to their transmitter site in Harrow, Ontario, as a
S.T.L. or Studio to Transmitter Link. It is not too uncommon to hear these
transmissions if you are around the Sandusky, Ohio, area on a clear
morning when the VHF/UHF E-skip is good. Transmissions on these frequencies differ from one station to another, but you will find them very interesting at times. Stations broadcast sporting events, remotes from a business in their community, news from the scene, weather from a person who specializes in weather, traffic reports from a helicopter, church services, conversations between news crews in the field, and even other radio stations being relayed to another radio station.
Something I should make mention of is some other frequencies which
the FCC allows to be assigned to broadcasters but seldom used. These
frequencies are Group-D 25.8700, 26.1500, 26.2500, and 26.3500. Group-E,
25.9100, 26.1700, 26.2700, and 26.3700. Group-F 25.9500, 26.1900,
26.2900, and 26.3900. Group-G 25.9900, 26.2100, 26.3100, 26.4100. Group-H
26.0300, 26.2300, 26.3300, and 26.4300. Group-I 26.0700, 26.1100, and
26.4500. Group-J 26.0900, 26.1300, and 26.4700. A company called Comrex
makes a small 1 watt transmitter which is used in the field to relay the audio portion of a TV stations audio to a wireless earpiece. If you are within a mile of one of these transmitters you can hear the signal quite clearly.
There are also three interesting frequencies of 1606, 1622, and
1646 kHz. These frequencies may be a thing of the past within months with
the proposed AM band expansion from 1600 to 1700 kHz, and I’m not sure if
any stations are presently using these for “legitimate” remote pickup
applications, however, they are still on the frequency list defined in Part 74 of the Federal Communications Commissions, Rules and Regulations. As a matter of fact, the Federal Communications Commissions has assigned some frequencies in the 1600 to 1700 band to stations that have applied to the newly formed “AM Band Extension”. Those stations include KJLA in Kansas City, KS, which will move to 1660. WLKF in Lakland, FL, which will move to 1680. WKCM in Hawesville, KY, will move to 1640. WAOK in Atlanta, GA, will move to 1670. KHVN in Fort Worth, TX, will move to 1660. WDNB in Daytona Beach, FL, will move to 1640. WONE in Dayton, OH, will also move to the new band, but the F.C.C. has yet to release the assignment. It is interesting to note that no assignments have been made for 1610, 1620, and 1630, so there may still be some use for Remote Pickup assignements.
There are also frequencies in the 900 megahertz, and up above 1990 megahertz which radio and television stations use. If you can find them, you can normally find some very interesting listening!