[IRCA] column on FM (& AM antennas) for casual listeners / fyi

["Eric Floden" <eric.f99999@xxxxxxxxx>]

this might be of interest, from Seattle P-I

http://seattlepi.nwsource.com/tv/344938_radiobeat27.html

 On Radioon Radio: Keep experimenting to get better reception

By BILL VIRGIN <billvirgin@xxxxxxxxxxxxx>
P-I REPORTER

Seattle is tough on FM radio signals. With hills, valleys, buildings and
tunnels, getting good reception can be a challenge for listeners.

Local radio stations try to deal with the challenges by moving to high
ground, which is why so many transmitters cluster atop Cougar Mountain or
the even taller West Tiger Mountain. Others use translators to fill holes in
their coverage area; KMTT-FM/103.7, for example, has an alternate signal for
downtown listeners, broadcast from the Metropolitan Park office towers, at
103.3.

And some listeners give up trying to get a signal over the air and rely on
cable-television services that also provide FM station signals.

Which is fine as long as the cable company offers the service. A change in
one company's offerings prompted this lament from a reader:

"Any clues on how to improve our FM reception? I bought an antenna at Radio
Shack but no signal improvement, and I've tried a 'co-ax' cable run up a
wall with equally negative results. We live in a downtown condo. What else
can we do?"

For some advice on how listeners can improve reception, as well as a primer
on how and why radio signals behave as they do in these parts, we turn to
Clay Freinwald, a 40-year-plus veteran of the broadcasting business who
handles engineering tasks for Entercom's radio stations in this region as
well as for KING-FM and Bustos Media; he's also a director of the Seattle
chapter of the Society of Broadcast Engineers.

Freinwald confirms that the region's topography creates headaches for
broadcasters and listeners alike. "This area is cursed with having a lot of
topographic variation," he said.

That doesn't automatically mean that listeners on the other side of a hill
from a transmitter can't hear anything. The idea that FM signals are purely
line-of-sight phenomena is "an urban legend mixed with a contraction of
physics," Freinwald said. "You can be in your home, you can't see Cougar or
Tiger Mountain, but you can receive FM just fine. ... Radio signals will
reflect (off buildings) and refract."

But that bouncing and bending has limitations. If you're trying to pick up
an FM signal while on the far side of Alki, with 500 feet of earth to your
back, "your FM reception is going to be putrid," Freinwald said.

Radio broadcasters try to mitigate some of topography's effects by getting
as high as they can. "The higher you go, the less shadow there is," he said.
KUOW-FM/94.9 is one of the last major holdouts on Capitol Hill, which gives
it great downtown coverage but limited reach around the region, he added.

Radio listeners in the country have been known to rig up all sorts of
external antennas in odd locations to get a better signal, Freinwald said.
For those who live in downtown buildings, aiming at an east-facing window
may help (since that's the direction most FM transmitters are located).
Apartment buildings often used to have a common rooftop antenna that
individual units could connect to, and some similar arrangement might work.
(KUOW's Web site suggests such steps as moving the radio to a different room
or connecting to an outdoor antenna or amplifier to boost the signal.)

Reception can also vary by radio, since "not all radios are made alike,"
Freinwald said. "Some are made for difficult situations."

Another possibility: HD radio, a digital technology that delivers both more
channels and a better signal. "It is wonderful, especially in downtown areas
where FM signals turn to mush" because of a phenomenon known as multipath
(defined as the same station's signal reaching an antenna via several
routes, sometimes at slightly different times). The only drawback is that HD
doesn't operate at as much power as conventional analog signals.

What about AM radio? Early sets had a place to connect an external aerial;
since AM waves are longer than FM "you need a lot of surface area" to
properly capture the desired station.

Eventually radio manufacturers came up with internal aerials, which meant
"an awful lot of compromise," Freinwald said. "The art of the (outside)
aerial has been lost."

There is a work-around for listeners. Freinwald suggests placing the radio
next to the telephone, or even coiling the phone cord and setting the radio
on it, or under it, depending on what works best. What you're doing is
borrowing the telephone line, through the properties of induction, as an
antenna. Properly positioned, "That radio will leap to life," he said.

Perhaps the best advice available is to keep experimenting. As both
broadcasters and listeners know, Freinwald said, "Radio signals do quirky
things."
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