meandering signal

Lee Maisel

I have always wondered what these meandering signals were, anyone know?

Mark_WS7M

I don't know but I have LOTS OF them. I also get what I call streakers where something rapidly zips all the way across the band and disappears. I also have more constant signals that just oscillate back and forth at a set point. I think these are some power supplies somewhere nearby. What is funny to me Lee is that before I had a pan I would hear this stuff and I just classified it as a "birdie" or something atmospheric. Now that I have a pan I can see them and it is pretty obvious that they are man-made in many cases.

George KF2T

Probably a switching supply or lamp showing thermal instability.

Mark - your "streakers" are likely ionospheric sounders. You can watch them on MHz-wide scales.

Mark_WS7M

So what is an ionospheric sounder? Is it something we produce to measure ionosphere? Where are they transmitted from?

Steve W6SDM

Poltergeist.

John

Streakers are people using military radios. You can see them many times switching back and forth and stopping on various signals. So they are definitely not caused by the atmosphere.

WX7Y

or the ones that streak across the band are merely hams that are transmitting at the same time as they turn the VFO knob checking a null point in there SWR on a Antenna. 
A poor mans SWR Analyzer,
Or even some one near you actualy using a Antenna Analyzer which puts out a week carrier to read the SWR like the MFJ -269's.

John

true, but these signals move a bit too fast at times and can be seen to be searching for signals and not tuning aerials.

Gene - K3GC

Judging by the answers it would seem that no one knows the answer so it must be aliens - Area 51?

Walt - KZ1F

Here is what I find interesting, and suspicious. I'll see one of those little rascals drifting up and back, to and fro. Often they'll drift right up to a signal I am listening to, not transmitting on just listening then just reverse course. So, in those cases it's not atmospheric noise as it is displaying intelligence.

Could it be a byproduct in the 6000? Does that phenomena occur with those with non SDR panadapter?

John

next time have a good look at how they move and when they stop sometimes you will see multiple carriers spaced about 17kHz  apart or the wood **** imitation pop up.

John

not that strong I would hope

George KF2T

More on the swept frequency stuff (not the meandering noise)... From Wikipedia:
In telecommunication and radio science, an ionospheric sounding is a technique that provides real-time data on high-frequency ionospheric-dependent radio propagation, using a basic system consisting of a synchronized transmitter and receiver.

The time delay between transmission and reception is translated into effective ionospheric layer altitude. Vertical incident sounding uses a collocated transmitter and receiver and involves directing a range of frequencies vertically to the ionosphere and measuring the values of the reflected returned signals to determine the effective ionosphere layer altitude. This technique is also used to determine the critical frequency. Oblique sounders use a transmitter at one end of a given propagation path, and a synchronized receiver, usually with an oscilloscope-type display (ionogram), at the other end. The transmitter emits a stepped- or swept-frequency signal which is displayed or measured at the receiver. The measurement converts time delay to effective altitude of the ionospheric layer. The ionogram display shows the effective altitude of the ionospheric layer as a function of frequency.

An interesting article with a ham radio connection: http://www.qsl.net/zl1bpu/IONO/chirps...

John

The vertical meandering line could be thermostats or other household appliances switching on and warming up. Central heating appiances can also cause havoc with broadband noise many Khz wide and they too drift up the band, but they are extremely strong and wipe out everything under the signal. I,ll get a screen dump next time I see one.

DH2ID

These transients are mixing products from different HF sources, such as broadcasting stations, which transmit a lot of harmonics.

These signals meander across the spectrum all the time and have done so
when I was a kid and listened on a tube receiver ;-)

Trying to decode them would be a waste of time.
And no, they are not ionosondes!

You can find a lot of signals and their specifications here:
http://www.sigidwiki.com/wiki/Signal_Identification_Guide

For the signal identification aficionados I recommend Artemis:
http://markslab.tk/project-artemis/
Easy to install and a great help! You have to download the program and
the database and unzip them into a folder.

WA2SQQ

Looks like I'm not the only one. Mine is there all the time, traversing across the 75m AM Window - 3.870 to 3.885. At first I thought it was emanating from within my home, but I've turned off every breaker and it's still there. Some days it's stable, other days it wanders back and forth. Typically abt S7

John

time to df it and see where its coming from. If its in your area, then you may well find the source.

DH2ID

Good luck with df-ing transients 8-) You'll probably df a lot of bc stations!

John

You never know what you may find down the road. DIY and grey imports from ebay etc. Its a nightmare

Steve W6SDM

John,  next time I see one, I will just switch over to the Wullenweber and get a bearing.  I'll need a couple of other hams to do the same.  Whatever it is, we'll find it.

Rick Hadley - W0FG

Steve, there was a day when i could have done that.  ;-)

John

Unfortunately, time marches on and as we get older, the brain is willing, but the body says whoa there. Over the yaers it seems that the HF bands are increasingly becoming a free for all. Signs of the times. At least I have my f3k and f1500 to keep me amused and content.