Coverage - 99.5 vs. 102.5 which is "better"?

[Eli Polonsky]

> From: "Lee Walus" <lwalus@cheerful.com>
> To: boston-radio-interest@rolinin.bostonradio.org
> Date: Sat, 02 Dec 2006 13:14:43 +0500
> Subject: Re: Coverage - 99.5 vs. 102.5 which is "better"?
> 
> Using a cheap Coby portable receiver, I was unable to pickup WCRB
> 99.5 at all in Kendall Square Cambridge. This may be due to the
> tall buildings and intermodulation distortion but perhaps these
> coverage maps are somewhat misleading.

The coverage maps display the (approximate) range of the signal
itself without taking into account external factors such as
other stations that may interfere with it in certain areas.

If the Prudential building didn't exist, you'd have no problem
picking up 99.5 in Kendall Square. The map is correct that the
signal is present in that area. However, it's being covered up
in your receiver by intermodulation from the seven Class B's
directly across the river on the Pru causing receiver overload
and a blanking effect of other signals from other locations.
On the Pru are WBOS, WTKK, WZLX, WBCN, WROR, WMJX, WXKS-FM.

On a cheap Coby portable, or most any portable, Walkman style
radio, or "boom-box" in the Kendall Square/MIT area, you'd be
lucky to hear anything besides the stations on the Pru and MIT
college station WMBR, and perhaps the three stations over at
One Financial Place (WERS, WHRB, WFNX) may cut through a bit
due to proximity. 

I'd be surprised if you could've gotten a clean, consistent
signal on 102.5 on a portable in Kendall Square, or of any of
the FM-128 stations. I've always found 102.5, as well as WODS
103.3, to be very tough catches on Walkmans in that area, as
they are usually covered up by a layered effect of Prudential
stations. The others from FM-128, WBUR, WJMN, and WBMX seem to
do slightly better there, perhaps the Pru intermod isn't quite
as concentrated on their parts of the dial, but not much better.

Of course, quality tuners such as most modern car stereos can
cope much better with this problem, and may still be able to
receive the stations in this area that a portable can't get.
On my digital-tuning JVC car stereo I find 99.5 to come in
with only slight picket-fencing in that area, but on my Sony
Walkman, it doesn't exist. I get a pig-pile of Pru stations.

Eli Polonsky