In article <1992Dec22.175647.1@engvms.unl.edu>, tmrdpsrs@engvms.unl.edu writes:
|> In article <1992Dec22.4230.11524@dosgate>, "sander schimmelpenninck" <sander.schimmelpenninck@canrem.com> writes:
|> > I often hear a simulcast of Tampa, Florida broadcast station WFLA
|> > in the Toronto area on 25,870 KHz, using narrow-band FM. The
|> > frequency lies in the 11-metre broadcast band, but the modulation
|> > mode puzzles me. Does anyone know who is sending this signal and
|> > why? According to the World Radio Television Handbook, WFLA
|> > operates on 970 KHz with 5 KW.
|> > --
|>
|> I have heard this as well and find it puzzling. I tuned it on 25,870 kHz AM
|> and it sounded pretty good. I heard it this last friday, Dec 18 at 2130 UTC.
^^^^^^^^^^^^^^^^^^^^
This is probably due to _slope detection_, whereas the edges of the passband
filter (as attenuation increases the futher you move away from the center frequency) act as a crude FM discrimator (varying voltage output as frequency
changes).
|>
|> Ron Synowicki
|> tmrdpsrs@engvms.unl.edu
--
John C. Kay Motorola
kay@motcid.rtsg.mot.com Cellular Infrastructure Group
