Pete & Renee Davis wrote:
Since 0019 (UTC), around 830 Hz.

It's clearly a news program. They've ID'ed themselves as Deutsche Welle
several times. They are reporting on Bush's Eurpoean trip right now
(0106 UTC).

Does anyone know if DW broadcasts on MW as well?

What kind of radio is this again?

My guess is you're hearing a DW shortwave relay via Radio Canada in New
Brunswick. Yes, even though your radio is tuned to 830 MW.

The "local oscillator" in your radio, when tuned to 830, is supposed to
put out a signal on 1285KHz. The radio mixes 830 and 1285, yielding:

830KHz
1285KHz
1285+830=2115KHz
1285-830=455KHz

It separates the last product, amplifies it, converts it to audio, and
feeds it to the speaker.

This 1285KHz signal from the local oscillator is not pure though. It
has "harmonics" - multiples of the desired frequency. For example, the
10th harmonic is on 1285*10=12850KHz.

Now, if there's a signal coming in from the antenna on 12395KHz, then we
have coming out of the mixer:

12395KHz
12850KHz
12850+12395=25245KHz
12850-12395=455KHz

The rest of the radio can't tell that last signal from the one that
results from 1285-830. YOu'll hear the 12395KHz signal.

There is a selective circuit between the antenna and the mixer; when
tuned to 830 MW it's supposed to keep any other signals from reaching
the mixer. This selective circuit is not perfect, it doesn't eliminate
*all* signal besides the desired 830. I would expect a New Brunswick
signal to be VERY LOUD at your east-coast location, loud enough to
"sneak through" this selective circuit.

--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com