TenTec
[Top] [All Lists]

Re: [TenTec] Carrier sliding across bands

To: tentec@contesting.com
Subject: Re: [TenTec] Carrier sliding across bands
From: n0dbx via TenTec <tentec@contesting.com>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sat, 10 Nov 2018 14:00:14 -0600
List-post: <mailto:tentec@contesting.com>
"Chirp Sounder" we called those in the navy.  I was in a reserve unit in the early 80's attached to NCS Nea Makri Greece.  It was a 100 watt transmitter on a vertical antenna that resembled the old AEA Isopole 2M vertical.  The control head was 8 miles away with a CRT readout.  It scanned from 2 MHZ and up, but I don't recall if it ran all the time or on demand.  I do recall a toggle switch that panned the display across the HF spectrum and gave you a rough idea of propagation.  Seems there was a readout at the tech control center of the receive site in town and another with the transmitters in the country.  Neat toys, but don't think it was used all that much.  Everybody just knew you went lower down when it got dark.

I can still hear those 100 WPM TTY printers running and smell the oil.  Wish we could get fresh caught deep fried baby squid here. Mighty tasty!

Darrel, N0DBX

On 11/10/18 11:29 AM, xanthi wrote:
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  I'm sure it would be too out of date to be of use  now.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
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec

_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec


_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
<Prev in Thread] Current Thread [Next in Thread>