Re: [TenTec] Carrier sliding across bands

[xanthi <xanthi@skybest.com>]

I was given a schedule for these ionosounders way back in the mid-90's.  
Using time and frequency on which the sweeping signal was heard in 
coordination with the schedule info, one could determine the location of 
the sweeping transmitter heard.
I have lost that info.  I'm sure it would be too out of date to be of 
use  now.  There are lots of these transmitting sites that transmit in a 
precise sequence with no overlap in frequency at the instance.  I'm sure 
there have been lots of additions and deletions.  I don't know if this 
info is available on the internet.  I have forgotten what the frequency 
limits for the sweep are.  I seem to recall the bottom was 3 mHz.
The engineer who gave me the information worked for a company that built 
two-way HF communications equipment that made use of the sweeping 
signals to automatically establish the best point to point 
communications path frequency at the time.  I expect it was probably 
used mainly by the government.
I most commonly hear these signals swish by on 40M these days.

de KY4P

------------------

On 11/9/2018 6:08 PM, Carlos wrote:
> Hi Bob,
> Yes, ionosounders appear as a moving clean carrier, they can sweep the band
> you are working in 3 or 4 seconds.
>
> What you describe looks to me like a harmonic of a switched-mode power
> supply where the fundamental frequency is set by an RC oscillator.
> Sometimes you can see several harmonics spaced by the switching frequency
> (for example, some noise every 60 kHz or so).
>
> 73,
> Carlos VK1EA
>
>
>
> On Saturday, November 10, 2018, Bwana Bob <wb2vuf@verizon.net> wrote:
> > An ionosonde, I think, would be a clean signal. I get switching power
> supplies sweeping across the bands in my neighborhood, but they drift very
> slowly and usually have a rough AC modulation on them.  The buzz is often
> found across the band at 20-30 kHz intervals.  Noise blankers won't wake
> them out.  I hate 'em!
> > 73,
> >
> > Bob WB2VUF
> >
> > On 10/24/2018 12:22 PM, MadScientist wrote:
> > > Ionosonde sounds like the most plausible source. I read the description
> and it looks very much like what I am hearing.
> > > Thanks!
> > >
> > > Gary
> > >
> > > > On Oct 24, 2018, at 11:16 AM, Mike Bryce <prosolar@sssnet.com> wrote:
> > > >
> > > > that could well be nothing more than a switching power supply (think
> wall wart here) and that’ s the oscillator singing away.
> > > > if you can, run the 7300 on a battery and pull the main breaker in the
> house. If the carrier goes away, start looking
> > > > if it’s still there, as your neighbors about pulling wall warts one at
> a time (good luck with that!)
> > > > Mike, WB8VGE
> > > > www.theheathkitshop.com
> > > >
> > > >
> > > >
> > > > > On Oct 24, 2018, at 12:07 PM, MadScientist <dukeshifi@comcast.net>
> wrote:
> > > > > Well, I entered the SDR world with my new IC-7300! That’s off topic
> but what I have observed with it is very much on topic.
> > > > > Over the past year I have heard, on all rigs, a carrier sweeping
> across the band (all bands). It is fairy strong.
> > > > > The landscape ,on the 7300 is fast enough to observe the nature of
> this. The signal consists of actually three peaks that typically start on
> the low end of a given band and sweep the range of 200 KHz in about 2
> seconds, with the speed being nearly constant, as evidenced by the sloping
> line that the signal makes on the waterfall display.
> > > > > That line is almost perfectly monotonic across the entire scope window.
> > > > >
> > > > > In addition, I sometimes see a carrier that makes a back-hand-forth
> movement on the waterfall display.
> > > > > Does anyone have any idea what be the origin of this signal??
> > > > >
> > > > > I know it’s not a radio artifact as I have herd this on a dozen
> different radios. Also, if I disconnect the antenna, this is never heard.
> > > > > Gary
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