[TenTec] Carrier sliding across bands

Sat Nov 10 15:00:14 EST 2018

"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  I'm sure it would be too out of date to be of 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 at 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 at 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 at 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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