In addition to operating our existing stations, we also seek opportunities for license upgrades and new stations,
in new locations. WPR retains communications consultants and attorneys in Washington to keep search for opportunities
for expansion or improvement, and have taken advantage of ways to improve signal coverage in any part of Wisconsin
and surrounding regions but as the years go by and the hundreds of stations all maximize their licenses, the odds
decrease for more such opportunities.
The Wisconsin Public Radio Engineering Department works hard to ensure good transmitted signals. It is important to
keep in mind, however, that radio broadcasting is a *system* that combines the performance of both the transmitter on
our end, and the receiver on your end of the system. Reception of local stations in your own town can be quite easy,
requiring no special thought or effort - turn on the radio and there it is. But when trying to pick up a more distant
station, there are definitely opportunities on the receive end to improve reception - especially for home and office
reception.
Your Radio Receiver
A good-quality radio is helpful, especially when more powerful local station(s) on adjacent frequencies bother your
reception of weaker, more distant stations. Note that radios noted for excellent sound and fidelity do not always have
especially good receiver circuitry. If your receiver's performance may be an issue, we can also recommend a radio that
is easy to use, inexpensive, has external antenna connections, and has good performance on both AM and FM. It is the
GE SuperRadio III.
This radio is available in electronics stores and websites such as amazon.com and universal-radio.com with nameplates
from G.E., R.C.A., or Thompson with model numbers such as "7-2887" or "RP7887". In most cases listeners find this to be
an excellent AM/FM radio at a good price - around $45 typically.
If your FM receiver has a "stereo" versus "mono" switch, try it in both positions to help reception. Some of our
transmitters run in stereo, others in mono - but if you have weak reception, your radio will perform better in mono mode.
Wisconsin Public Radio stations that carry primarily music programming transmit in stereo mode, and those that carry
primarily information and news are in mono. Since stereo operation degrades the signal-to-noise ratio of the system,
mono operation has greater signal range. If the station does not carry music or other stereo programs, it is wise to
run it in mono for the best reception across the widest geographical area.
FM Antennas
For FM broadcasting, the antennas are very important, and the built-in radio antennas can often be inadequate.
Adding an external antenna can be a relatively simple way to improve reception. Does your radio have external antenna
connections on the back? A simple dipole antenna made of wire would likely be of help, or a more elaborate antenna in
your attic or on the roof is also possible.
In fringe area reception, the reflections and bounces of the signal from nearby objects (known as multipath distortion)
can be a big factor in reception success or failure. An antenna move of just a couple feet can bring the signal in
beautifully for one station and be a bad spot for another, thanks to the geometry and the wavelength of the frequencies
involved. The signal direct from the transmitter either adds or cancels with the reflected signals in different places.
Experiment with the location and orientation of the antenna.
Wisconsin Public Radio can send you an FM dipole antenna that will be easy to attach and move around for best
reception. You can buy these yourself inexpensively at electronics stores. Old TV "rabbit ears" antennas can also
serve FM nicely.
More elaborate FM antennas can be attic, roof, or tower mounted. TV antennas can often also serve as effective
FM antennas. Use a "splitter" to route the signals to the TV and radio. An excellent yet inexpensive FM antennas
can be purchased at Radio Shack - their catalog number 15-2163 for about $25. Mount this antenna as high as you can
and rotate for best signal.
AM Antennas
The built-in radio antennas for AM usually do a good job, but if your radio has an external AM antenna connection
on the back, a simple wire or loop can be of help.
The orientation of the radio with its internal "bar" antenna can be important - always try rotating your AM radio
to find the best signal. This is also true of external loop antennas that you might try - don't hesitate to experiment
with the shape and location of the antenna.
Noise Interference
When fighting noise interference it can be very helpful to locate the radio and/or its antenna away from likely
sources of interference such as light dimmer switches, fluorescent lighting, computers, microwave ovens, battery
chargers, TV's, VCRs, day/night and motion-sensing light fixtures, touch-sensing lamps, and the like are all known
noise-makers. You can eliminate the possibility that the noise source is in your own home by listening to the
interference on a battery-powered receiver and turn off the "Main" electrical circuit breaker to your property.
If the noise goes away you know the offending device is running on your household power lines and can then narrow
down the location of the offending equipment by turning off individual breakers instead of the "Main".
A new source of noise interference has recently cropped-up which seems to be related to the installation of
a new type of traffic lights. The troublesome intersections seem to be of the new "LED" type rather than the older
incandescent lamp variety. Our tests reveal a lot of broadband noise interference near those locations. It was
not just on WPR stations' frequencies, or even just the low end of the FM band - it was throughout the band. I
confirmed that the character of the interference changed depending on which traffic lights were being lit, so that
seems to correlate it with the light system. It impacts our more distant FM stations more than local full-power
stations, but the locals can be bothered too. We've had little luck so far in working with the various county and
municipal transportation departments responsible for these installations - We encourage you to report such interference
to the traffic engineer in your town.
Interference from Other Radio Stations
If your interference seems to be only found "on top of" one radio station, or if you can hear other radio programming,
then perhaps the source is another broadcast transmitter or radio device. In cases of interference from a station on the
next dial position, a good quality radio with better "selectivity" will be helpful. See the GE SuperRadio mentioned
above.
Another possibility is that there is a local source of interference around your house on the specific desired
frequency - computers and other microprocessor-controlled devices can radiate spurious signals either across a band
of frequencies or on specific frequencies such as on or around 90.7, 88.3, etc. Do you have any "modulators" or other
devices to let your satellite receiver, PC, MP3 player, etc play through your radio? These are often a source of
interference. Experiment by turning such devices off and listening to the impact on your radio reception.
Reception Changes Through the Day, or Across the Seasons
Sometimes FM signals sound noisy or distorted due to the combination of signals direct from the transmitter site
with other signals reflected from hills, buildings, trees, etc. Since these signals take different paths to your radio,
they can either add or subtract from each other, causing distortion of the intended signal. Don't hesitate to move
your radio and antenna around to find the best reception location.
Multipath is easy to identify when listening to FM in the car. You might experience alternating good
reception/bad reception as you drive along, or even a rapid flutter of the signal. If you happen to stop a location
where the signals are canceling each other and the sound is noisy or garbled, you can usually ease your car forward
and the reception will change - a clear indication of multipath interference. Many car receivers attempt to reduce
the impact of multipath by automatically switching the receiver to mono mode. Some even have multiple antennas hidden
around the vehicle.
The changes in vegetation and foliage as the seasons change can have an impact on these FM reflections - move
your radio or antenna to find a new "good spot" and restore reception.
Sometimes distant FM stations in other towns and states can cause interference to WPR stations. This is due to
signal propagation enhancements caused by atmospheric conditions that cause FM and TV signals to go far beyond their
normal ranges. This is a natural phenomenon, which tends to happen more frequently in the summer months.
Temperature inversions, particularly over Lake Michigan, can cause such interference from distant stations.
While we were experiencing interference to our local stations, folks in the distant towns were getting interference
from our stations - at least it is "fair and balanced" in that fashion. This sort of interference is unlikely to last
beyond a few hours or at most a couple days.
AM signals can be harder to hear at night than they are in the daytime. Each day, between sunset and sunrise,
distant AM signals can reflect off the upper layers of the atmosphere and be reflected back to ground hundreds of
miles away, causing interference to local stations. The Federal Communications Commission requires AM stations to
adjust their power and antennas to minimize interference to other stations at night, so either or both of these
changes can impact your reception of a WPR AM station. The electrical noise of nearby thunderstorms can also hurt
AM reception.
Special Considerations for HD Radio Reception
Our general experience has been that HD signal coverage is slightly less than typical analog AM or FM coverage.
This means that if you can receive a clear signal on the normal AM or FM station signal, you have a good chance of
receiving the HD digital with a proper radio. And of course, in cases of weak analog signal, you may be able to
make changes to your antenna to improve your reception and pick-up the HD signal.
Some listeners have reported audio drop-outs or short silences on the HD2 services. This is due to marginal
signal strength at the radio. The fix is to adjust the antenna placement to get a better signal. It is important
to remember that the HD Radio multicast channels (HD2, HD3, etc), unlike the HD1 channel, do not have an analog
signal for the radio to fall-back to when digital reception is lost. So a listener with weak or erratic reception
that is losing the digital signal will experience periods of silence until the signal is regained.
Wisconsin Public Radio is proud to be among
the first radio stations in the United States to implement the new "HD" digital radio service. With the new service,
some listeners in fringe areas may need to review basic radio reception techniques.
Wisconsin Public Radio strives to have the best on-air signals possible. We operate our transmitters at the Federal
Communications Commission licensed parameters for power, antenna configuration, and modulation. Each station has a
different antenna height and power output, and can be located in very differing terrain - thus each has a different
coverage range.
