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Author Topic: 450 khz (between LW and MW) Bloomberg Radio at 3:36 on July 10, 2021 UTC  (Read 1039 times)

Offline Molvania Poacher

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Apologies if this is something obvious and/or already discussed, but tonight I stumbled upon broadcasting in English on 450 AM. Listening between 336 and 410 UTC, the signal intermittently improved, and I clearly IDed the program content as live Bloomberg Radio, comparing it to the Bloomberg internet stream and hearing clear IDs on 450 khz. The contents of the transmission ran about 34 to 35 seconds ahead of what was on the internet official stream for Bloomberg Radio. News, interviews, weather, sports, ads (for NY and NJ businesses mostly). Any thoughts on the reason for this signal here?
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Offline Ct Yankee

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Here's a guess. Bloomberg Radio in NYC (WBBR) is on 1130 am.  If there are one-third harmonics, that would land it at near 377 am - about where you had your best reception.  My experience is terrestrial radio always runs ahead of the webstream, including shortwave.  This has been helpful when I try to ID a station on the radio, I can hear radio and then see if it matches webstream
Zenith T/O G500, Zenith T/O Royal 7000, Emerson AR-176, Zenith 8S154, T/O 7G605 (Bomber), Tecsun PL-880, Zenith 5S320, Realistic DX 160 using 40 feet of copper wire. 
QTH:  Durham, Connecticut (rural setting, 15 miles north of Long Island Sound)
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Offline Molvania Poacher

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Thanks CT Yank! That was my leading theory, but the math seemed a little off. I also saw some old references to tunnel radio TIS-type systems (for instance in Boston in the Dewey Square Tunnel under South Station in the 1990s) using 450 khz for transmitting a signal to drivers that would cover the entire AM broadcast band while underground. But that seemed pretty darn unlikely. Enjoy your tour of duty on the other coast and thanks for sharing your thoughts.
All reception direct.
QTH 70 miles north of Boston.
Kenwood R-2000 with about 100 feet of wire thrown up in the trees.
eQSLs super appreciated to molvaniapoacher@gmail.com.

Offline pinto vortando

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My guess is that what you heard was a mixing product of a strong AM band station signal (possibly nearby).
450kc is very close to the 455 kc IF typically used in receivers.
Das Radiobunker somewhere in Michigan

Offline Molvania Poacher

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Thanks PV...I was thinking about that very plausible theory as well. But as luck would have it, the signal has been even stronger tonight. I was therefore able to copy both identical audio as simultaneously on 1130 (WBBR from NYC) as well as several clear "Bloomberg 1130" IDs on the 450 khz feed.

So Ct. Yank wins the Kewpie Doll (which will go nicely in his award-winning collection).

Mystery solved. Thanks for the replies and collaboration.

MP
All reception direct.
QTH 70 miles north of Boston.
Kenwood R-2000 with about 100 feet of wire thrown up in the trees.
eQSLs super appreciated to molvaniapoacher@gmail.com.

Offline Ct Yankee

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Thanks but a quarter century ago I swapped my Kewpie Collection for land speculation atop the "Old Man of the Mountain"  :-\
(Non-New Englanders free feel to google said natural feature/state symbol circa 2003. I think that is where Poacher's antenna was originally located and his anchoring technique that year has lead to "Old Man" conspiracy theories/PhD thesis topics and  federal research grant allocation in Hanover, NH. ;))
« Last Edit: July 12, 2021, 0322 UTC by Ct Yankee »
Zenith T/O G500, Zenith T/O Royal 7000, Emerson AR-176, Zenith 8S154, T/O 7G605 (Bomber), Tecsun PL-880, Zenith 5S320, Realistic DX 160 using 40 feet of copper wire. 
QTH:  Durham, Connecticut (rural setting, 15 miles north of Long Island Sound)
qsl please to:  jamcanner@comcast.net  (Thank you)

Offline NJQA

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I don’t know that I buy into this “sub-harmonic” idea.  Mixing products seem more likely.

If you are actually hearing WBBR 1130, mixing products from a station on 680 kHz (or 1580 kHz) could produce a signal on 450 kHz…but I would expect to hear audio from both stations.  You didn’t report that.

Also, does WRCA 1330 Boston carry Bloomberg?  They are closer to you than NYC.

If you were tuned to 450 kHz, and your radio had a 455 kHz IF, the local oscillator would be at 905 kHz.  If WRCA 1330 also mixed with the 905 kHz local oscillator, then the product would be at 405 kHz which is near to the frequency you were hearing this unknown signal.


Offline Ct Yankee

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I had thought about the 1330 Bloomberg Radio station in Boston but dismissed the thought as Poacher mentions ads for NY/NJ businesses.  Having listened to WBBR, they carry more tri-state commercials than national advertisements.  Good thought though about the Boston Bloomberg station, there are actually a pair nearby there: WRCA 1330 AM in Watertown-Boston and WNBP 1450 AM Newburyport-Boston.
Zenith T/O G500, Zenith T/O Royal 7000, Emerson AR-176, Zenith 8S154, T/O 7G605 (Bomber), Tecsun PL-880, Zenith 5S320, Realistic DX 160 using 40 feet of copper wire. 
QTH:  Durham, Connecticut (rural setting, 15 miles north of Long Island Sound)
qsl please to:  jamcanner@comcast.net  (Thank you)

Offline Brian

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I don’t know that I buy into this “sub-harmonic” idea.  Mixing products seem more likely.

If you are actually hearing WBBR 1130, mixing products from a station on 680 kHz (or 1580 kHz) could produce a signal on 450 kHz…but I would expect to hear audio from both stations.  You didn’t report that.

Also, does WRCA 1330 Boston carry Bloomberg?  They are closer to you than NYC.

If you were tuned to 450 kHz, and your radio had a 455 kHz IF, the local oscillator would be at 905 kHz.  If WRCA 1330 also mixed with the 905 kHz local oscillator, then the product would be at 405 kHz which is near to the frequency you were hearing this unknown signal.
I don't agrree with the lower harmonic theory either.
Almost every time I have heard of someone hearing a MW station down so low, it's to do with double the IF. Some radios are 450, so Boston 1330 would be 430 Khz. Still not 450 though.

Offline Sparx McGee

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Long shot theory:  radiated IF from a very nearby receiver tuned to Bloomberg.   More likely to be at 455kHz, though, and extremely weak.    Another long shot:  a spur from the Bloomberg transmitter.
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Offline Ct Yankee

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Sparx - Not a bad thought but freakish in that on two consecutive evenings, a nearby radio to Poacher in New Hampshire would be tuned to Bloomberg Radio New York rather than a pair of nearby Bloomberg stations in Boston.  Some New Yorker on vacation in New Hampshire? Possible but I would have been more convinced if it was WCBS or WFAN with a nightly baseball team to follow.
Zenith T/O G500, Zenith T/O Royal 7000, Emerson AR-176, Zenith 8S154, T/O 7G605 (Bomber), Tecsun PL-880, Zenith 5S320, Realistic DX 160 using 40 feet of copper wire. 
QTH:  Durham, Connecticut (rural setting, 15 miles north of Long Island Sound)
qsl please to:  jamcanner@comcast.net  (Thank you)

Offline NJQA

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Maybe a clue is in his tag line “….trusty rusty 1980s portable with about 140 feet of wire thrown up in the trees…..”. That is a lot of antenna for most portable radios.  It is possible that his portable radio is overloaded and generating this signal internally.

Offline Sparx McGee

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Yeah, I think that's the most likely scenario.   I usually need to use a MW band stop filter or a high pass filter to attenuate the broadcast band to avoid images at lower frequencies.  My IF radiation and transmitter spur theories are highly unlikely in comparison.
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Offline Molvania Poacher

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Quite the mystery...thanks for the ideas. A few additional facts:

The 80s portable is a Uniden CR-2021 (a pretty decent little rig) for what that's worth.

I can hear the signal again tonight, and yes there does seem to be a (rather tough to copy) second signal mixing in there. I didn't notice it before because the relatively distorted sounding quality of the Bloomberg audio and the intensity of the QRN made it tough to hear. Definitely TWO signals here however.

It was definitively the NY WBBR "Bloomberg 1130" ID, with NY/NJ and tri-state related ads.

Maybe an overload, but I've never experienced that phenomenon before, and I've used this exact radio since 1984. Still, there's a first time for everything.

In the interest of science, I've broken out my Kenwood R-2000 and will see if I can replicate the phenomenon, failure of which will suggest that the McGeesian Hypothesis should be promoted to an Axiom.

Again, thanks everyone for the thoughts and suggestions.
« Last Edit: July 17, 2021, 0248 UTC by Molvania Poacher »
All reception direct.
QTH 70 miles north of Boston.
Kenwood R-2000 with about 100 feet of wire thrown up in the trees.
eQSLs super appreciated to molvaniapoacher@gmail.com.

Offline pinto vortando

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Poacher,

See if you can ID the second signal.  If you can determine its frequency it may be possible to calculate which combination of mixing
products are causing what you are hearing.  Sometimes it becomes obvious what signals are causing the mixing, however, most
often you will drive yourself crazy trying to figure it out. 

What you are experiencing is not unusual especially on a portable.  They typically have a lot of sensitivity and not much in the selectivity
department... an open invitation for spurious responses.

Good idea on trying the Kenwood.  Its dynamic range specs look so-so but gotta be better than the portable.
Das Radiobunker somewhere in Michigan