I have a little info gleaned from the net for you. Because this signal is not a pirate beacon I will move the thread after replying.
Please do not post the same logging across multiple areas.
https://www.transmission1.net/viewtopic.php?t=56825Mystery RTTY signals
Post by grafter » 09 Jul 2019, 08:25
I finally recorded a narrow band of signals I've been hearing for the last few years and wondered if the collective could shed any light on their origin. When propagation is towards Italy and Spain multiple RTTY beacons appear on 27.551 (USB). I've heard them on some of the European SDRs so appear to be authentic and distant but so far I have been unable to decode anything from them.
I'm aware of the continuous FSK wave buoy signals above 10M but these remain a mystery so any clues as to their origin or function would be very much appreciated.
Here's the video of this morning's reception.https://vimeo.com/347029020Second Lead for youRe: [UDXF] 26-28MHz FSK
janJul 23 #286
Hi Kurt
Interesting message!
I hear this FSK signal again today on frequency 27.551 usb , On Websdr from Italy "
http://roma4.ddns.net/" you can also hear this FSK 27.551usb ,
73s
Jan
netherlands
Verzonden vanuit Mail voor Windows 10
Van: KD7JYK DM09
Verzonden: donderdag 22 juli 2021 20:43
Aan: vhfskip@groups.io
Onderwerp: Re: [vhfskip] [UDXF] 26-28MHz FSK
"I finally got a decent capture of the mystery FSK signal that appears
across the CB band when I have Es to Spain. I've uploaded a video and
the original IQ file in case anyone is able to suggest its purpose or
the type of transmission?"
Are you on the UDXF group, and did you get the Datawell telemetry links?
I also posted the following yesterday, but didn't see it bounce back
to me through UDXF, did you see this, by any chance? The post also had
some photos, and if this forum allows them, I can follow up with them in
a later post:
Initial UDXF post:
"I hear these mystery signals in Florida also, on multiple US CB
channels when conditions are right, and it appears to be something
different from the Datawell beacon. The mystery data appears to be some
kind of query and response"
My response:
I enjoy hearing about such things.
I first saw "Class C" equipment in the 1980's, and began chasing it down
in the 1990's. The service goes back to the 1950's, and from the 90's
onward, devices made to operate on the 27 MHz frequencies was in the
millions per year. Most are very low powered, and can only be heard up
to a few hundred feet by design, but some frequencies, and equipment
allow up to 4 Watts output, and one frequency, 25 Watts output, both of
which can result in global coverage, but are generally heard in the
range of miles.
By the early 2000's, I began acquiring much of the equipment that
produces the different signals, and was able at one time to ID all but
perhaps two that could be heard regularly over the past forty years. I
had a Yahoo Groups page up briefly with several hundred photographs of
equipment, and recordings, but as soon as they switched to "Neo", I lost
control of the group. Yahoo was never able to make groups fully
functional before eliminating the groups entirely several years later.
The types of equipment is all over the board. Remote controlled toys,
to computer accessories, irrigation controllers, to wireless card
readers, paging systems, alarm systems, hydrological, and meteorological
telemetry, medical equipment, remote control switches, garage door
openers, wireless modems, traffic light controllers, emergency pumps to
prevent flooding, even a device from the early 80's that measured the
chewing rate of reindeer. Some equipment operates relatively rarely,
for example, lightning detection and alert systems. Some send one-way
data bursts, some interrogate each other for status, others communicate
back and forth regularly. Eventually, I was able to ID the make,
model, and application of much of the equipment, just by the sound of
the signal as heard over the air. Over time, much of the equipment
moved to the 315, 433, and 900 MHz (eventually to 2.4, and 5.8 GHz) ISDM
bands, so for those that monitor ISDM bands, the swath of non-stop
signals you still hear, and resultant RF 'fog", was once focused on only
a few HF frequencies.
About fifteen years ago, when HF propagation conditions were "bad", I
was able to track down scores of signals, often to the source, see,
photograph, document, then acquire examples of the equipment, bits and
pieces, documentation, et cetera. When conditions are "good", signals
pour in from all over, making it difficult to find the source. Was what
I heard regional, from another state, or country? Tracking signals up
to tens of miles is somewhat easy, even across several valleys, mountain
ranges, and lakes, even to sources inside buildings, but some I had to
give up on, all indications suggesting their source was somewhere else
on the continent.
At one point, I found myself in competition with an odd, unknown at the
time, entity in acquiring some of the equipment, and prices began to
skyrocket. I was eventually contacted by the CEO of a US based company,
and we exchanged stories. I was trying to ID equipment, and prevent
much of it from being destroyed, he was trying to run a business. As it
turns out, his company was acquiring as much equipment as possible from
one manufacturer, and pulling a single IC from the circuitry, as it was
no longer available, then disposing of the remains. The IC was not
important to me. We struck a deal. He doesn't drive up the prices,
well beyond my price range, and in exchange, his techs ship everything
they can't use, to me. Quite the deal for him, his acquisition costs
dropped, didn't have to pay electronics recycling fees, and everything
was shipped flat-rate from his end, so essentially free. A few items
acquired here and there, increased exponentially. A friend likened the
acquisition, and storage of Class C items as the ending scene in the
movie Raiders Of The Lost Ark, the warehouse filled with crates of
unique items.
As with many things, other aspects of life took priority, and although I
continue to acquire unique equipment as I come across it, the forum
dedicated to such equipment is long gone. Receiving, and tracking
equipment installations have changed, I have not had HF equipment in
operation for such activities since ~2014, and until late last year, I
was interested in what appears to be a wideband radar signal covering
roughly 100 - 500 MHz simultaneously. At times, I think of creating my
own webpage, far more extensive than what Yahoo allowed, and perhaps
spread out the information across other platforms, such as YouTube, and
Facebook.
In the US, the Class C frequencies are, in MHz:
26.995
27.045
27.095
27.145
27.195
27.255
Powers range from mW to 25 Watts in the US, depending on operating
frequency.
Frequencies, and usage in other countries is comparable. Many persons
disregard the frequencies as uninteresting, probably because almost all
modern references mention their application to remote controlled toys.
This can be compared to likening all radio activity, globally, as being
for music broadcasts, because some frequencies are used for that, too. I
suspect we all know better. Radio controlled toys are one minuscule
aspect of what can be heard on these frequencies, and not too likely,
due to a range of tens to hundreds of feet.
What CAN be heard is roughly 3/4 of a century of devices up to thousands
of times more powerful, with antenna systems ranging from embedded, to
hand-held, to mobile, and some comparable to large broadcast facilities
on mountain tops.
I've had one system operating on 27.255 MHz for several years. Listen
for a digital signal ~1.5 seconds long, repeating about every 8 seconds.
I'm unsure how much of such equipment is still in use, so what you
hear may be regional, or it may be something I operate.
Some aspects of the installation can be seen in the attached photos. As
you can tell, what you see, may not be what you think, or expect. For
reference, the height of the portion shown is roughly that of a 3-story
building.
Enjoy.
Kurt
Topic: RTTY Beacon or transmissions on 27.551 USB (Read 1430 times)
