Mystery Signal

[N5PVL]

I have been seeing this mystery signal on 30 meters fairly regularly... It starts off on one side of the waterfall display, slowly making its way across to the other side. #( Constant, steady frequency drift )

The result at any given time is the "angled" appearance you see here. This was captured around the nieghborhood of 10.040 MHz, though I have also seen it elsewhere on 30 meters at different times.

http://www.uspacket.org/images/misc/mystery.jpg

Does anybody know what this mystery signal might be? Has anybody else seen the same thing?

Just curious!

[ve2nsm]

Quote[/b] (N5PVL @ Oct. 25 2005,20:24)]I have been seeing this mystery signal on 30 meters fairly regularly... It starts off on one side of the waterfall display, slowly making its way across to the other side. ( Constant, steady frequency drift )

The result at any given time is the "angled" appearance you see here. This was captured around the nieghborhood of 10.040 MHz, though I have also seen it elsewhere on 30 meters at different times.

http://www.uspacket.org/images/misc/mystery.jpg

Does anybody know what this mystery signal might be? Has anybody else seen the same thing?

Just curious!
It would be good to see the vertical vector (time) so we can know the speed of the drift.

[KC0W]

Since 30 meters is a shared band, anything can & does go on there. Many amateurs have spent a lot of time trying to decrypt military RTTY & other strange signals.

I have never heard of anyone having any luck doing so.

You are not the only one wondering what the signal in question is........With "numbers stations" you at least know what the general idea is. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif


Tom kcØw

[N5PVL]

VE2NSM says:
Quote[/b] ]
It would be good to see the vertical vector (time) so we can know the speed of the drift.

I can't help you there... Too many variables there, too much uncertainty.

I captured the image with MixW, which has several options for waterfall speed, then there is processor speed to consider, and even window size. ( I run MixW in a medium-sized window, floating in the middle of the screen. )

Not long after I posted this, I walked into the hamshack and saw the same signal, going the other direction!

It could easily be a piece of equipment at or near my QTH generating a 'birdy', so I posted here, wondering if anybody else had seen the same thing on the air, which would eliminate the birdy theory.

Note that the rate of drift is not constant... It appears to slow down and speed up slightly, going in fits and starts.

[ae1x]

Sounds to me like someone searching for MUF or signals. It could easily be military in origin. We have to remember that this is a shared band and there are military and commerical interests present. Also, we must not interfere with them, they are the primary users.

Ken

[kl7aj]

It must be a signal from a Knight-Kit T-150 http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

eric

[KA3RFE]

It's a space alien landing beacon, natch. When I had antennas up for 30m I heard all sorts of strange stuff, too. The first few times I heard those things I didn't know what they were and thgouth something was wrong with the radio. Sheesh.....

[WB2WIK]

Swan 350 warming up.

http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

First thing to do if you really want to try to track this down (which of course could be impossible, but anything's worth a try) is get concurrance from others that the signal you're seeing/hearing is really there and others are hearing it, too. If nobody near you says they hear/see the same thing, it's probably something very local to you, maybe even in your own home.

If others agree the signal's really there, you might be able to determine its point of origin if some of you have directional antennas and can peak the signal. Even rotary dipoles, which are quite common on 30m, will help do this if you use two or more of them. Homemade DF loops can do the job even better (sharper null than a dipole's peak) if the signal's strong enough to hear with a small loop.

I have interference that slowly sweeps some bands, and I mean really slowly (maybe 10 kHz an hour, could go either direction) and sounds like wideband digital hash, maybe S4-S5 or so, varying in intensity with frequency and different antennas I use. My noise blanker actually does a good job of nearly canceling it.

After six months of trying to figure out what the hell it was, I finally switched off my daughter's cable modem and it disappeared!

Now to figure out how to cut the crap coming from that appliance....since Road Runner's so nice, I might just ask them to replace it and see if the next one does the same thing.

WB2WIK/6

[K0RGR]

It looks like the switching power supply in my old PC. One of my neighbors has something I can't find that generates a very broad (30 Khz. wide) signal on the high end of 30 meters that is about S4 all the time. That's part of my problem with working digital stuff on that band, apparently. I've been suspicious of my ICOM receiver, thinking it was an internal birdie, but I detect it on another receiver, too.

If it's slowly drifting, I'd be suspicious of cheap switching supplies.

[WA5VQM]

An Eico 753?

[w8znx]

meisner signal shifter?

[KF0RT]

Quote[/b] (WB2WIK @ Oct. 26 2005,10:13)]Now to figure out how to cut the crap coming from that appliance....since Road Runner's so nice, I might just ask them to replace it and see if the next one does the same thing.
Wouldn't it be in violation of Part 15 if it did that? They SHOULD replace it.

Had a similar problem here -- a constant S5-S6 noise level that pretty much covered all bands. Got fed up with it one day and found it by "process of elimination." I started by killing the main breaker to the house (with the rig running on a car battery). That made it go away. Turned the mains back on and switched each circuit off until I found it. Then, it was just a matter of going to that circuit and unplugging stuff until it went away. (A cell phone and a cordless phone are great for keeping you in touch with the audio while you do all this. Just set the cordless phone next to the speaker and walk around with the cell phone.) It took all of about 20 minutes.

Turned out to be an Ethernet hub my son-in-law installed on the wife's computer so he could have Internet access for a laptop in the kitchen.

73, Rob

[WB2WIK]

Funny thing about Part 15.

Home user appliances like a cable modem should meet CFR 47, Part 15 Class (B). However, lots of devices that actually do meet Class B can interfere with sensitive receivers just fine. Using a sub-microvolt receiver and a beam up sixty feet, I can probably hear hundreds of Class B devices all over the place, especially if I'm aimed at them.

The din of all that is probably what's slowly but surely increasing all of our noise levels. Forty years ago there was very little to interfere with us, but today there's millions of things.

Besides Part 15 being pretty irrelevant in the face of amateur radio applications because we're dealing with sensitive receivers and large antennas, nobody's enforcing it, anyway.

With probably 50 Part 15 devices in every home in America, I guess we'd need inspectors on every block in the country, and we'd keep them pretty busy...

WB2WIK/6

[N5PVL]

It doesn't look ( or sound ) modulated to me, but I guess sometimes its hard to tell.

[WB2WIK]

Quote[/b] (N5PVL @ Oct. 26 2005,16:46)]It doesn't look ( or sound ) modulated to me, but I guess sometimes its hard to tell.
If it's not modulated, it would have to be a steady carrier. Any carrier that pulses on and off or can be digitally decoded is modulated.

[WA9SVD]

Quote[/b] (WA5VQM @ Oct. 26 2005,14:22)]An Eico 753?
That would be an Eico "Seven-Drifty-Three." MY HS Radio Club had one. We were able to stay in-band most of the time...

[kc0vrs]

Quote[/b] (N5PVL @ Oct. 25 2005,17:24)]Does anybody know what this mystery signal might be?
It is our government communicating with aliens http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif

[kb2vxa]

Hi Mysterians,

I'd rather hear it than see it but my guess is an ionosonde.