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I recently discovered your Wobbler web site. The Cuban wobblers have been widely reported in the international DX section of the National Radio Club's DX News magazine. The wobblers have been received here in New Hampshire too, if you'd like to add it to your list of states and provinces. [New Hampshire - 3/31/05] I agree with you, a Cuban origin seems almost certain, and the Cuban broadcast transmitters the source of the Wobbler signal. Direction finding by several people including myself, have narrowed the location of some Wobbler sources down to specific Cuban regions in the vicinity of known Cuban broadcast transmitters. Your assessment of the likely and unlikely causes of the Wobbler is also a well considered one. I find myself moving from one possible source and cause to another as different people make such good arguments. If the only examples of the Wobbler were the strong disruptive signals that have been heard at considerable distances from their apparent Cuban origin, I would also have to put considerable stock in your jammer suggestion. The problem is, from my close proximity to Cuba I can heard Wobblers more distant listeners can not. These range from those extremely strong, overpowering signals that are heard beyond the midwest, to very weak ones which require special effort to hear even as close as I am. This is sometimes related to signal strength, but more often the intensity of the fluctuations. You can see a log of my Wobbler listening on the Wobbler web site. The log includes a relative strength indication on different frequencies and times each day. It seems to me if the Wobbler were intended as a jammer, there would be no reason to produce a signal that requires special effort to hear, let alone cause interference. The bubble jammer, which is the kind of device you describe, has been suggested and a comparison of it and the Wobbler is presented on the Wobbler web site. The similarities are there, but the Wobbler is not nearly as effective as a true bubble jammer would be. If intentional, I would have to describe the Wobbler as more a nuisance than a jammer. But then, a nuisance to whom? Just the Cubans as far as I can tell. Not to say that isn't a possibility. Who knows, maybe the Wobbler is the result of a malfunctioning, unstable, underpowered jammer! As to your argument against the suggested unintentional cause of unstable power. Certainly a power grid like ours in the U.S. would not tolerate wide instances of instability. The power grid in Cuba is a far smaller and dare I suggest, unsophisticated arrangement of just a few power generators. The failure of one generator has been reported to have diminished power generating capacity by 30%. True it was a major generating unit, but still, that indicates a pretty small grid, as far as generator capacity goes. And such a small grid, it would seem, might become generally unstable, all generators staggering under the extreme overload produced by the loss of this substantial resource. Rolling blackouts are an acknowledged fact of life in Cuba, in an effort to deal with these power shortages. Even if the overloaded grid is not the direct cause of transmitter instability, how about emergency backup generators which it would seem could well be called into service during these rolling blackouts. Obviously, an emergency generator would not be connected to the grid, supplying power only to the station. It would not be unreasonable to assume that these emergency generators are not the most sophisticated of units either, nor are they likely to be substantial in every case nor well maintained. A local, stand-alone generator, itself unstable and probably overloaded at least at times, would seem to also be a likely source of some sort of transmitter instability. I do not have any idea what affect an unstable power source would have on a transmitter, which itself may be antique and poorly serviced. But the range of Wobblers from barely perceptible to wildly exaggerated, just seems to me to be the result of some unintentional situation, rather than any planned activity. But that is just an opinion, not the result of any first hand knowledge of broadcast transmitter engineering. And certainly with no knowledge of Cuban government intentions. [3/31/05] It sure seems to me that the Cubans are the source for this carrying-on. AND let me assure everyone this carrier frequency shifting cannot be be accidental. The Cuban government is trying to accomplish something, and it sure seems that they are fitting wobbulators (there is such a device) to broadcast station transmitters. My best guess is that they want to jam every channel "on the cheap" from spanish-language Floridian and from Puerto Rican stations (on skywave). Since I first started DXing MW BC station (in 1957) and through the times I've engineered stations until now, I've not seen a single example of an AM BC transmitter shifting in frequency like those Cubans are. Generally, crystal-control won't permit a transmitter to wobble around in frequency like they're doing, and when a crystal breaks or the oscillator tube gets so low that it won't oscillate then the transmitter through feedback paths will start oscillating freely and around the assigned frequency...because that's where it's tuned. And in that case, the carrier frequency will be FM modulated with hum, noise, and transmitter modulation. Can't blame the wobbulation on instability of the Cuban power grid, either. That kind of instability would make it impossible to synchronize generators in a power system....especially a mix of small and large machines. As soon as a real-world system starts experiencing such instability, circuit breakers between Campbellsville (KY) and Hell (MI) would have tripped big time. As paranoid as Castro is, his toadies at ICR would have thought up this jamming scheme on general principle alone. [3/30/05] Is this the signal you have been hearing in Florida? Not exactly strong here in Austin, but tonight is the first time I have heard it. WKY is the English station with a bit of unknown Spanish under it. I often hear XEs on 930; never have heard Cuba such that I could ID it on 930. This signal does loop towards Cuba from here. RX is Yaesu FT-1000MP with one meter box loop. Sounds intentional to me, jammer or something. [Texas] For whatever it's worth, you can now count me as one who has heard the Wobbler. Heard it this evening (~7:45 pm east coast time) on 930 khz. while driving (2003 Subaru Outback, stock radio) to work to pick up a few items. It came and went a few times for the 15 or so minutes that I was listening. At peak, it was obvious. Mostly it was inaudible or faintly heard fighting it out with a presumed WBEN and WFMD. [Delaware] The wobble here seems to follow modulation. So, my feeling is that it is very low voltage to the transmitters causing this, or extreme over modulation. [Florida] What has led me to my current position, tenuous as it may be - that the Wobbler is caused by power fluctuations causing transmitters to malfunction - is the following: 1. Other possibilities, such as jamming, do not make much sense considering the impact. 2. DF'ing has pointed toward existing transmitters - though this is still preliminary. 3. Hearing the Wobbler always on Cuban frequencies, regularly, both day and night. 4. Acknowledged near 50% power shortages across Cuba due to a major generator failure. 5. The use of sugar mill generators to augment the diminished power, a potential source for instability. 6. The fact Cuban power is interconnected by a grid and instabilities affect the entire island. 7. Rolling black-outs which would imply back-up generators may be used to keep stations on the air, another source of power instability. 8. The ability - demonstrated by recent DX tests - of code and sweep tones to cut through where voice and music can not. This leads me to accept that, if a malfunctioning transmitter can produce a wobbling carrier, then it could be heard much farther and more clearly than the underlying signal being transmitted by the station. 9. Wobblers that are heard widely are extremely vigorous both in the frequency and amplitude of the carrier swing, using the full power of the carrier to propagate a very simple signal. It would seem to make sense this simple signal would be detectable much farther than complex broadcast modulation, which is almost incidental when one of these things really gets wound up. The three stations I have tentatively DF'ed are all 10kW transmitters (according to WRTH), which could put out a very wicked CW signal for some happy Cuban ham. There are those who insist a malfunctioning transmitter could not possibly produce the Wobbler signal, while others are convinced that is precisely the situation. I am not qualified to say one way or the other, but for now accept the possibility. This is why I am a bit cautious of the idea that the wobbler is being sourced from an existing Cuban xmtr, because I believe if the source was an existing xmtr and it is on the same freq, then propagation would cause the existing xmtr's signal to be similarly loud. This could be checked by establishing if a really loud wobbler can be attributed to propagation alone by detecting other similar BC signals at good level. The trouble is the lack of sufficient comparison points (other signals from similar location, or similar freq) along with the idea that the simplest explanation usually is the best, and here the simplest explanation is xmtr malfunction. So then, episodes of really loud wobblers need to be primarily linked to propagation variations, if you assume that there is a maximum upper limit on just how much power a wobbling xmtr can throw out towards us. That is, can a 5 kw xmtr generate 25 kw of wobbling? I doubt it. Give a listen to R. Habana Cuba on 6.000 MHz for a similar wobbling sound...more like a "weebler" though, hi. This at 0400 UTC... [Florida] I was just doing a scan before going to bed and stopped at 930 kHz and the Wobbler jumped right out at me, it's usually over everything here too. It is coming and going but I've only had it on for 5 minutes and twice it has been very strong and almost always audible. I wasn't even thinking of it the first time. It's wobbling up a storm tonight. [Massachusetts] Yesterday (3/14) I tentatively DF'ed another one: 820 CMJT - 10kW - Ciego de Avila, CA - R.Pregresso This one was coming in strong on Sunday but when I tried DF'ing, the Wobbler had subsided. Yesterday the Wobbler was back but the station much subdued, plus splatter from 810 ZNS3 1kW booming in from Freeport, Bahamas, contributing to the difficulty to zero in. This result is somewhat less certain than the other two and I will make another attempt to nail it down firmly, next time I have a good signal and strong Wobbler. Cuban stations are rather unpredictable as to their day to day signal strength. [Florida] A new, distant reception report of the Wobbler on 930 has been received from Michigan, adding a new state to the Wobbler coverage area. The current reception list according to my account is: CO DE FL GA IL MA MI MO NJ NY OH OK ON PA RI SC TN 930 3/11: WFXJ FL, WRVC WV, WTAD IL, WHON IN; WSEV TN sunrise and sunset; no sign of the Wobbler overnight, but it was horrible at 7 and 8pm EST. [Tennessee] By the way a friend in MI I've been sending your wobbler posts to, hears it every now and then; he sent me an audio clip. Quite an interesting sound. Today the Wobbler was coming in strong on 620, mid afternoon. I repeated my set-up in the back yard from yesterday, and ran a DF on this one. This time I was expecting the signal to come from:
620 CMGN - 30kW - Colon, MA - R.Rebelde - 22.69N, 80.857W -
191.57° - 256.6 statute miles.
The only other station listed on 620 in Cuba by the 2005
WRTH is CMKF at 1kW which would be to my southeast.
While not as easy to null as 930 yesterday, I was able
to place the Wobbler signal between 180° and 190°
from me, right on expectations. The other station vying for the
channel was WDAE Sports Talk 620 - 5kW - St. Petersburg, FL,
and some splatter from WIOD News/Talk 610 - 5kW - Miami.
So that is two for two, Wobblers DFed toward Cuban
radio station locations.
[Florida] As I mentioned in my previous post, assuming a Cuban connection I expected the Wobbler to be originating from 930 CMJS - 10kW - Ciego de Avila, CA - R.Reloj - 21.86N 78.71W - bearing 164.42°, 320.5 statute miles from my location. However, the results I got that first time were more on a line to the Bahamas or beyond to Puerto Rico. Not surprisingly, the results were different this time. The problem areas Gerry had pointed out to me, all were present in my listening location. Fortunately, in the back yard they were not. The results this time could not have pointed more directly at the CMJS location. Even with my inexperience, I have some confidence in these results. [Florida] Most DF attempts have pointed toward Cuba, more or
less. A few though, have
either been unable to find any directional aspect at all, or
pointed east
from locations like Colorado, but not
southeast. No one has reported
hearing the Wobbler from the west coast region, CO and NM as
far west as
reports go, so far.
From where I am in south Florida, these things are daily
occurrences and are
often heard over anything else on their
frequency. This would also favor a
Cuban connection. One suggestion of locations off
the main island of Cuba
has also been mentioned.
I would say Cuba is the general consensus for probable
location, though more
precisely than that has not been suggested. As
the DF reports have shown,
it is very difficult to get a narrow direction on the
signal, so even from
here, locating on one end of the island or another has not
been possible.
The nature of the origin of these signals is still
uncertain, with power
problems and transmitter malfunctions as popular
possibilities. Some favor
jamming of some form, from or at Cuba. Nothing so
far has given a definite
edge to one cause over any others. On this the
most popular opinion is
probably unstable power.
[Florida] Seems to be very close to zerobeat with few to some deviations to higher pitch. What is interesting is that it is disappearing for parts of a minute, unless it just fades quickly, or is going truly zerobeat. It seems to be going in "fits and starts". I've just about abandoned my earlier theory about noise on unstable MUX lines between cities. Right now I basically don't have a clue about the wobbler's cause. (I've heard that said, before, hi) Heard here in Central PA at 2320 EST; loops almost exactly E-W on my Quantum QX Pro. Definitely not directed from Cuba. [Pennsylvania] Several people have commented on how effectively sweep tones cut through the clutter during DX tests. During both the WTTB test last weekend and the WNTP test a couple months earlier, I was able to easily hear the sweeps and some code, but nothing else. This caused me to rethink my hesitancy to accept Cuba as the source of the Wobblers. What had kept me from that conclusion were the several reports from the northeast and midwest of hearing the Wobbler through local or near local stations, with no sound of SS. The sweep tones have shown their ability to cut through when no voice or music can be heard. It now seems reasonable to assume the Wobbler tones could just as easily produce the interference that has been observed. That being the case, I now believe that Cuba or vicinity could indeed be the origin of the Wobblers, as several DF results have suggested. That of course still leaves unanswered what the cause of the Wobbler is. Bad power, bad transmitter, or even malicious or clandestine intent, still remain possibilities. Does anyone have an idea about how much power it would take for the source to cover 1/2 of the US with this noise? A few hundred watts or more? [Illinois] ---------- Unless it's very close to me it's got to be a lot more powerful than that, it's really blasting in here tonight sometimes. [Massachusetts] 870 2/14: WWL LA, horribly overmodulated Reloj Cuban, the Wobbler, WINU IL 1100 2/16: WTAM OH, the Wobbler, WCGA GA sunrise and sunset. [Tennessee] I just am not hearing "modulation" on the "wobble". I think the wobbler is a separate signal and not the carrier frequencies of those stations. I have WTAM partially or almost completely nulled (keeps changing) and the wobblers are unmistakable, I only heard two a few times, one would start as another one was already in progress, I definitely heard two, I am having problems with WTAM or I think I would have an easier time. In fact one of them is wild tonight, it's not only wobbling it's wooping. 3 or 4 high pitched woops that are slower in rate and then dips quickly in frequency and the rate goes way up at the same time, very strange. Also when I null N-S the wobbler does not diminish at all, the only thing I see that directly affects it is how deep the null is for WTAM. I have not been able to null it either that I can see, it only seems to decrease in proportion to the station's strength as I null the station which in this case tonight is WTAM. I can't see any rhyme nor reason with this thing at all. [Massachusetts] There is still some detail I don't understand in all this, and that is whether (1) the wobbling is the actual carrier frequency of the station itself, being shifted back and forth, with the station's modulation riding on top of it -- or -- whether (2) this is a separate signal just sitting out there a few hundred Hz from the real carrier, and wobbling around by itself, acting as a shifting unmodulated carrier beating against a stable on-channel carrier to create the actual audio pitch beat note. At 10:35 PM CST in WTAM 1100 null can hear the wobblers up here! [Illinois] There is indeed a very strong wobbling/bubbling sound on 1100 at around 2315 EST tonight. But not on other frequencies although the band does seem rather fluttery. By phasing I can get this sound up and over WTAM and this is the same phase mode I generally use to bring up LA stations. [Pennsylvania] At 8:45-8:58pm ET 2/15/05 I noticed the Cuban on 1100 in Cleveland null, VERY unstable, but unlike the slow woob-woob-woob wobbling noise, this is a much more rapid oscillation. [Missouri] The wobbler is audible on both 1100 and 930 in Memphis. [Tennessee] As I continue to monitor this thing (as of 8:57pm ET 2-15-05) the wobbling oscillations of the carrier seems to vary in the speed of the wobblings in pretty much a random fashion, i.e. at times it slows down to the sort of wobbler noise that we've all been talking about, then it speeds up to a very rapid oscillation. That just doesn't sound deliberate to me; the explanations that have been put forward of bad power grid in Cuba etc. certainly sounds plausible in this case--the carrier sounds like a bowl of Jell-O. [Missouri] I've got a wobbling noise at 0100 ET, piggybacking on a strong R. Reloj with poor audio. Kinda sounds like a bubble jammer but it's intermittent. It sounds like a transmitter or antenna problem to me; it's too random to be intentional. Besides I see no reason why Fidel would want to jam 870 unless it's something personal against the Trucking Network. I trust we don't jam. I don't know the exact technical reason for this but I simply take it as another sign that things continue to fall apart in the Socialist Paradise. [New Jersey] I have been listening to the wobbler on 870 now for perhaps half an hour from maybe 2300-23:30 EST. It is accompanied by a very strong het which is actually a little strange sounding to be a het. I also received the wobbler for maybe a minute on 1100 and it was also accompanied by the same het. The strange thing is that the het on 870 is pretty constant but the wobbler comes and goes, at first I thought it was maybe propagation but upon repeated listenings it always seems to start at the same volume, does not fade in or out in other words. It seems to start at the beginning of a wobble if that makes sense, there is a distinct beginning and end to it. The audio frequency of the wobbler has changed as has the rate at which it wobbles. The het nulls out almost due South from Massachusetts, but the wobbler does not seem to diminish along with the het although I am not sure of that last statement. [Massachusetts] I vote for an unstable power grid because I hear the same effect on Cuban ham radio signals on 160 meters every night. [Florida] This wobbler is neither strong enough, acoustically effective enough, predictable enough, targeted well enough (against apparent or obvious targets) or consistent enough, to be jamming of an intentional nature. Possibly, but playing devils advocate for a second ... suppose that the jamming is being done to affect a U.S. station. If the transmitter for their people is omni-directional, and the jammer was on the north shore beaming north, then it's possible they could jam us without affecting their people. How many times have we discussed seeing tower lights, but not hearing a station because it's so directional. Tonight I recorded two Wobblers from two radios on 870 and 930 simultaneously, leaving no doubt that at least those two are not synched in any way. Other recordings of two Wobblers occurring together on the same frequency are just now being made on 870. Very low under WWL at QTH here in Lima, well under WWL and splatter from WCBS. [Ohio] Just a random thought, perhaps the wobbler is coming from Cuba and it is some sort of artifact from a subcarrier being used to send multiplexed subcarriers, each containing data streams, and the subcarrier is leaking out of a channel bank demodulator and entering the audio stream. Some sort of instability is then inadvertently modulating the subcarrier, creating the actual wobble effect. Imagine that scarcity of transmission lines between cities is leading to use of mux'ed data on single wideband pairs. Maybe it's not really from Cuba. Remember Radio Swan in the early 60's? Maybe it's from a little bit farther south than Cuba. Radio Swan was a CIA operation from Swan Island. Could be easly heard all over the southern U.S. There is more here than meets the eye (or ear). Wouldn't it be something if Castro was testing plans to disrupt U.S. communications. Heard them on 930. Difficult to null but rough bearing from Pensacola is in the neighborhood of 130-140 degrees, or a line that runs through eastern Cuba. ---------- Averaged the DFs on 870 and 930 and the DF is closer to 125-135 degrees. Miami is 125, Guantanamo is 131, Camaguey is 135 from Pensacola. It's extremely difficult to get even a shallow null on these things. The DFs above are really a guesstimate based on null bearings and maximum strength bearings. I don't feel particularly comfortable with them at all, but it's the best I can do at the moment. I'd feel better just saying that they appear to be SE of me. There are some perplexing anomalies associated with this phenomenon that I'm going to have to chew on a bit. [Florida] The consensus of many seems to be heading toward malfunctioning, or maladjusted Cuban transmitters. If so, one can expect these problems to be resolved eventually. I can't believe Fidel would condone an obvious demonstration to the outside world, of failed Cuban technology to go uncorrected. If nothing changes, then the questions of where and what and why are still up for grabs. I'm not so sure these frequencies might not be //. Given that we've found over the past number of months increasing numbers of Cuban stations on the Progreso and Rebelde nets apparently carrying Reloj at times during evenings and overnights, it's becoming increasingly difficult to determine what's really going on. It doesn't seem to me that modulation would account for the fluctuating heterodyne produced when de-tuning a few hundred Hertz in USB. Of the choices, this would seem to eliminate modulation. I also have trouble believing a half dozen transmitters would all be malfunctioning from time to time and often in groups of two or three at the same time, in exactly the same way. Power supply problems have been suggested, but these wobbling transmitters are in different regions, and others that do not produce the Wobbler are in the same regions. But that may be related to transmitter types. I don't know if an unsteady voltage source would produce the Wobbler effect or not. That would seem to be a good question to put to a transmitter engineer. Nor am I sure the question of direction is answered yet either. When DFing along the east coast, a N/S null automatically points suspicion at Cuba If DFing from somewhere other than there should indicate a direction other than Cuba, then that leaves the whole question still largely open. At least one such measurement found a dew east null from Denver area, not southeast, and on another occasion and a different frequency, no discernable direction from Denver area could be found at all. This doesn't eliminate Cuba as the source, neither does it eliminate much else all along the east coast, with certainty. Collecting a wider sample of DF result would seem to be needed. So far no example of the Wobbler has been found on a frequency where there is not also a Cuban station. Nor have there been any reports of the Wobbler from locales that do not routinely receive Cuban broadcasts. This certainly points suspicion at Cuban as being involved in some way, but not necessarily the instigator. On the other hand, I would not be at all surprised to learn it is being done intentionally. Whether to communicate or signal somehow to or from Cuba, or to aggravate, or to propagandize that the US is jamming local broadcasts in the people's paradise. The possibilities still abound. I tried FFT software last night, but the update rate is too slow to track the frequency variations in the carrier (assuming that they exist). However, the carrier that I believe was from the Cuban transmitter looked "smeared" or "fuzzy" compared with the others. I also tried listening to the carrier in CW mode, and I had the distinct impression that it was FM'ing rather than steady. So, there's at least some evidence that this is not an audio-only effect. [Ottawa, ON, CA] I've spent a lot of time listening to this thing and have noted a few characteristics. When it is coming in strong and gets going good, you will have no trouble recognizing the wobbling sheet metal sound. When weaker, it may sound more like a varying tone. If it's coming in strong but not vigorous in its activity, it has a definite low rumble - maybe a gargle - sound. I can hear this rumble easily with my sub woofer stereo and tuner, and also with earphones with good low frequency response. The thing is, there is both strength and vigor. The strength puts in the rumbling and overall volume, the vigor adds the extent of the variable frequency swings. I've run a spectrogram on the audio and when wound up it varies from zero to 5 or 6 thousand Hertz, sweeping at 4 to 6 Hertz. The strength seems to be fairly consistent over a period of time. The vigor comes and goes in a matter of seconds. It could be nothing but the rumble, have spurts of shallow, short wobbling, and then burst out with a wildly swinging full throated wobble, then settled back to just a rumble for a while. You may have caught it in an uninvigorated mood. The wobbler has tentatively been DF'd as coming from Cuba. Let's not forget that area US posessions include Guantanamo Bay, Desecheo Island and Navassa Island. Maybe a US transmission from one of those areas? [2/13/05] It does not waiver in signal strength and my S meter stays generally solid. So I don't think it has an FM component. I also tried listening to it in FM mode and that doesn't produce anything obvious. My guess is that it is entirely an audio element. [2/13/05] I don't think there is any evidence that this problem could be caused by the Cuban power grid. The symptoms point to a misadjusted RF oscillator frequency control loop; the gain of the control loop is set too high by some means, and the result is a noisy/chaotic control loop oscillation which drives the carrier freq to vary around the target. Why so many dispersed transmitters with the same symptoms? They're probably all the same transmitter model or at least fundamental design, all old and about the same age (60s vintage), and probably the same guy working on them all. [2/13/05] Re. a bad transmitter affecting a good one, it certainly does on the receiving end. When listening in AM mode you'll get a heterodyne between the two signals, which will make the audio from the stable tx be perceived vary in pitch at the same rate as the carrier variation on the unstable tx. Again, the best way to distinguish which of those two transmitters is actually unstable is to inject a stronger, stable carrier, i.e. go to a SSB mode on your receiver; then the audio from the bad transmitter will sound unstable and the good transmitter will sound rock solid. This was the case on 930 last night; Reloj sounded fine, but Surco sounded wobbly when I tuned in on USB to 930.00 KHz. [Florida - 2/13/05] Now the second part of this would be to figure out if the sound we're hearing is modulation, or the carrier FMing. If it's modulation, I would suspect that Fidel is just being a putz and jamming stations. If it's FMing, then two thoughts come to mind. One is technical malfunctions run amuck in Cuba, and the second being some sort of communications. My money is on the putz factor, as history has shown that Cuban officials enjoy running a stick across the cage and stirring up the animals. [2/13/05] For what it's worth, I can easily null the wobblers here in North GA and the direction it is coming in strongest from is towards Florida and Cuba leading me to believe that something is up with their networks. I have turned on 3 separate radios and I got a parallel on 930 and 870. 1100 was off by a about 10 seconds. (slower). [Georgia - 2/13/05] If something else were putting a coherent signal - a suppressed carrier signal for example - on one of these frequencies, that varied as the wobbler does, wouldn't the mixing of those two signals affect the audio of the non Wobbler signal? [2/13/05] Wobbler heard on 870 *very* briefly (only 1-2 seconds long) here in Tulsa at 2227 CST 12FEB05 w/WWL nulled, sounded exactly like a big piece of sheet metal being shaken rapidly, nothing heard since. [Oklahoma - 2/12/05] So far, I've had it strong on 1100, weak on 870 and audible once on 930. Has not been heard on the strong Cuban frequencies like 600 and 670. [2/13/05] ---------- Definitely on 870 a half hour ago (11pm). Noticeable distortion on the Cuban Radio Reloj audio. Frequency shift on the "RR" code ID for example. Voice audio distorted almost as you'd hear when a tape is slipping in a cart machine. [Rhode Island - 2/12/05] Hearing it louder on 870 than any other frequency so far. It is audible under WWL and semi-local KJMP. It seems to be coming from all over the east. I can hear it equally everywhere from 60 degrees to 150 degrees magnetic with no discernible peak direction. I still don't hear it on 930. It is still weak on 1100 and it peaks at 90 degrees (due east) magnetic just like last night. After hearing it coming from everywhere east of me on 870 I'm not sure how much faith I would put in the due east signal on 1100. It could be coming from other directions but being masked by other stations on the frequency since it is weaker to me on 1100. The direction I'm hearing it best from could simply be the only direction I can detect a signal from because of the other stations. [Colorado - 2/12/05] I never thought the wobble sounded like an FM'ing transmitter. From hearing my share of FM'ing Latin American stations over the years, I would expect the FM to be fairly random sounding and the audio to be a bit unclear. The wobbles would also have some correlation to the modulation. The wobble clips I've heard sounded much more "intentional" and un-random. My theory is that Cuba is messing around, on purpose. [2/12/05] I don't know if anyone has suggested the Wobbler is a deep or dark mystery, but mystery it is, witness your own four suggested explanations. I would add at least atmospherics as a fifth possibility, and others have suggested jamming OF Cuba in addition to FROM Cuba. Then there are the suggestions of some interplay of signals, or mystery signals in their own right, emanating from some secret government cave. So a mystery definitely is there, if for no reason other than all the proposed explanations. [2/12/05] There doesn't seem to be anything common about the frequencies on which it's been heard - 870, 930, 1100, did I see 910 ? And there also doesn't seem to be anything common to US stations on those frequencies which would be readily audible in Cuba. [2/12/05] 1. It's some kind of deliberate jamming tactic. This seems unlikely - why would they impair the audio of their own service? 2. A number of aging transmitters have somehow developed the same fault simultaneously. This also seems unlikely. 3. The fault is not in the transmitters themselves, but in one or more of the audio distribution networks, thus affecting multiple transmitters. This sounds a bit more plausible, but I don't think anyone has observed any correlation between the wobbling happening on different frequencies. 4. The wobbler is caused by a problem in the power source: the line voltage dips, the regulation in the transmitter's power supply can't handle it, so the transmitter FM's. Perhaps all of the offending transmitters are in a part of Cuba where the electrical grid is particularly unstable. [2/12/05] I may have had it on 1100 last night. If that is what I heard it's extremely weak here. It did sound somewhat similar to the recording that was posted a couple days ago but was far less metallic sounding. What I was hearing last night looped precisely east-west from my location 20 miles north of Denver. I could not hear it when I aimed the loop SE-NW which would favor Cuba. [Colorado - 2/12/05] I have it here too at 0254 really strong equal to the Cuban station and WTAM at times. It really sounds like the Cuban is running the wobbler through their board as I hear no carrier interference to the Cuban other than that from WTAM. Weird! [Georgia - 2/11/05] Trying to listen to CtoCam on WTAM right now, hearing a wobbler in the background. [New York - 2/11/05] To make a long story short, I am 150% convenced that what we are hearing is something to do with weather war and mind control. Now you can put me in the luny bin. [2/9/05] It is not an unattended xmitter. Sounds like some sort of radar. We had something similar out here a few years back on 1136 but it was not up and down like this one. The Army was doing testing around Area 51 back then. When the position was triangulated by local people, the xmitter shut off and never came on again. [2/9/05] A transmitter with no modulation and just left running will sound like a warbler. [2/9/05] Also heard here in NE Pa. and loops South. [Pennsylvania - 2/3/05] Was also noted here on 930 last night for the first time, around 2130-2200 ELT. [Delaware - 2/3/05] I've heard it on about half a dozen different frequencies. In most, if not all, cases, it seems to be associated with a Cuban station. Several times I've heard FM'ing on the Cuban station's modulation that seems to be associated with the "wobbling". I doubt that it is intentional jamming, but I have no idea why this stuff would be emanating from a number of Cuban transmitters, unless it's some kind of strange network problem down there. [Ontario - 1/30/05] I heard it in Columbia SC. [South Carolina - 1/30/05] I've heard it on 820, 930, and 1020 khz. Very puzzling indeed. [Georgia - 12/31/04] I took a listen to your clip and it's surely not just a broken transmitter. What it is (and who) is a mystery to me. [12/30/04] Yeah, I have heard it on 910 and on 750. The questions are from where are these signals emitting, against whom are they jamming, and why? I have heard it described as sounding like a wobble board. Does anyone have answers to the above questions? [Maryland - 12/16/04] At 0430 EST, 15 December 04 I had the jammer on a new frequency of 930kc. This is the same jammer that has been reported on 1020 and other frequincys. A sort of woberler sound. Like someone shaking a large piece of tin. Quite strong at times. [Tennessee - 12/16/04] At 23:30 CST there is a weird sounding noise on 820khz in WBAP null. Sounds like someone flexing a large piece of thin sheetmetal. [Illinois - 12/6/04] |