Re: [IRCA] [NRC-AM] 1610 mystery station - Invitation to #mwdx

["W. Curt Deegan" <WWWR@xxxxxxxxxxxxx>]

Jim,

I'm probably out of my depth, but it seems to me even a full double 
sideband signal would have only one carrier against which a BFO could 
interact.  That being said, tuning to the three frequencies in CW 
mode would not produce a beat note on each sideband, only on actual 
carrier frequencies.

It is harder to discern beat notes from modulation in USB/LSB mode 
because both the beat note and modulation can be heard and are 1 
kHz.  In CW mode only the beat note is heard and there are three 
distinctly separate ones on the 1609, 1610, and 1611 frequencies.

I even fired up the big set to test my theory since some radios don't 
implement a true CW mode.  The NRD-535D confirmed what I had been 
seeing with the RX-320D and Spectran, three carriers.

There are a bunch of tones heard in AM mode, around what I think are 
three carriers, accounting for both modulated tones and heterodynes 
produced by the beating carriers.  As I've mentioned, I get tones 
every 1 kHz from 1607-1613, in AM mode.

I have also observed that the carriers vary in strength independently 
amongst themselves, which would tend to suggest separate signals, not 
a common one.

Last night there was one carrier at the times I checked and an 
impressed 1 kHz tone.  Tonight it sure seems to me that there are 
three carriers, possibly with 1 kHz tones on some or all and the 
resulting hets as well.  Also, I believe at some point last night 
there may have been three carriers -- reported by other -- but only 
for a short period, unlike tonight.

Those are my thoughts right now but more thinking is certainly in 
order.  I'm probably all wet, so don't hesitate to set me straight.

Curt
-------
W. Curt Deegan
Boca Raton, (southeast) Florida
[JRC NRD-535D; LF Engineering M-601]



At 05:57 PM 11/29/2006, you wrote:

>In Oak Ridge, Tennessee, the signal on 1610 is now
>(6 PM) quite clear.  Looking at the RF (at IF) on a
>scope shows pretty full modulation.  Kicking in a
>3 kHz mechanical filter allows one sideband at a time
>to be lopped, yielding the "two-tone" pattern.  That
>observation then concludes that this is a full-carrier
>doublesideband signal.  Strength is similar to the
>10 kW carriers on nearby frequencies but below
>the level of the 50 kW signal in the low 1500s.
>Some fading so it is not local to eastern TN.
>
>- JimT


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