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Topics - Teotwaki

Pages: [1] 2 3 ... 5
Utility / 11,175 KHz USB loggings
« on: July 19, 2019, 2252 UTC »
22:51Z  19July2019
Hearing Fisherman and CornMill discussing a net, mentioning authentication ANT with Quebec and FYS with Alpha

Shortwave Broadcast / 9395 KHz WRMI
« on: July 17, 2019, 0349 UTC »
pretty good signal here with some slight fading

03:50Z 17July2019

Utility / 11,175 KHz data stream
« on: July 15, 2019, 0128 UTC »
01:29Z 15July2019

Possibly someone threw the wrong switch?

I heard a few normal USAF voice messages and next thing this odd data signal pops up. Within the USB channel there are three main peaks appearing on my waterfall display

Equipment / Commercial RDF Equipment from Japan
« on: June 03, 2019, 1343 UTC »
This topic is related to the loggings of fishing Drift Net Beacons being monitored in these threads:

I ran across this web page about the Japanese RDF set  TAIYO TD-L1706


The TD-L1706 is a mobile radio direction finder (RDF), developed in the late-1980s by Taiyo Musen in Japan. The TAIYO TD-L1706 was developed primarily for use aboard ships, for finding the direction to a beacon and for locating fish. It was soon discovered however, that the device was also suitable for locating (clandestine) transmitters on land, not least because of its very compact antenna.

In the Netherlands, the Radio Monitoring Service then known as RCD first started using the TD-L1706 in the late 1980s, in combination with their custom-built PAN-1000 intercept receivers.

Block diagram from the very nice web site Crypto Museum

Display unit pix from the very nice web site Crypto Museum

HF Beacons / MOVED: frequency hopping set of repeating pulses
« on: May 08, 2019, 1313 UTC »
This topic has been moved to HF Mystery Signals as it does not appear to be a transmit mode that is useful as a beacon. It does post an interesting puzzle to solve!


A very interesting catch but it is not a HF Beacon. This topic has been moved to [Shortwave Pirate].  https://www.hfunderground.com/board/index.php/board,3.0.html


Utility / USCG 5696 KHz USB
« on: February 26, 2019, 2247 UTC »
approx 22:40Z 26 Feb

tail end of a radio conversation between COM-COM and another station who gave location as
 35 42 N and 120 38 W which could be over Paso Robles, California so maybe it is a USCG aircraft asset.

Shortwave Broadcast / WTWW 5085
« on: February 07, 2019, 0516 UTC »
05:14z  07 FEB

Big signal, about 20 dB over the noise.  Didn't recognize the song that just played. DJ was just teasing the local hams in ARES then encouraged others to join their local ARES

Playing "Ain't nothing like the real thing"  Marvin Gaye and Tammy Terrel

Equipment / CW Keyers for Beacon Transmitters
« on: January 30, 2019, 1935 UTC »
I have been researching what is currently available and will list them in this thread.

If you add any suggestions keep in mind they should be

 - Easily programmed for the Morse characters used to ID the tranmitter (not restricted to a custom read-only-memory that must be mail-ordered)
 - Low power consumption
 - Must start up in the beacon mode upon power up. (Many Iambic Beacon/CW keyers will not do this)
 - Not too expensive. $20 or less?


There are some interesting Arduino style keyer programs on GitHub that could probably be modified to allow beacon mode upon power-up

Example  https://github.com/k3ng/k3ng_cw_keyer

Peskies / 9033.255 KHz USB 01:24Z
« on: January 17, 2019, 0120 UTC »
On right now. Sounds like Chinese

Shortwave Broadcast / 5085 KHz WTWW
« on: December 04, 2018, 0431 UTC »
Great signal has been rolling in for the last hour. I don't recognize the female singer at the moment 04:35 UTC 4Dec

Shortwave Broadcast / Voice of Vietnam 7315 KHz 01:44 UTC 29Nov
« on: November 29, 2018, 0141 UTC »
Booming in here over S9 on my NRD-525

Equipment / Inexpensive signal sources for CW transmitters
« on: August 22, 2018, 1725 UTC »
I've been watching the various flavors of Chinese direct digital synthesizers (DDS) on eBay and you can get a lot of capability for low prices.

Rather than order a crystal from some slow and traceable source you can use one of these to easily choose a frequency for the HF bands

Sorting through the Ebay listings is a pain as the sellers are rarely technical enough to understand what they are selling. The product's description can range from fair to terrible to non-existent.


DDS Function Signal Generator Module DDS Sine Square Sawtooth Triangle Wave



Main AVR DDS V2.0 signal generator features:

Dedicated high speed (HS) signal output up to 8MHz;
DDS signal with variable amplitude and offset;
DDS signals: sine, square, saw, rev saw, triangle, ECG and noise.
216 LCD menu;
Intuitive 5 button keypad.
Frequency adjusting steps: 1, 10, 100, 1000, 10000Hz;
Restores last configuration after power up.

You could unplug the circuit board's display to save a bit of power when it is operating unattended..

The DDS is the green circuit board in the lower half of the picture.

YouTube video review  https://www.youtube.com/watch?v=2zojBi2fvwU

The reviewer points out some design flaws but for under $14 it is hard to complain.

HF Beacons / Unknown Dasher? 4095.288 KHz
« on: August 02, 2018, 0124 UTC »
4095.288 KHz  Dasher? Slow rate, maybe 2 seconds. Weak but readable

Shortwave Broadcast / WTWW 5085 KHz
« on: July 03, 2018, 0359 UTC »
signal booming in at 04:00 Z

Just played the song "I can See Clearly Now" by Johnny Nash and now "Hey There Georgie Girl" by the Seekers

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