HFU HF Underground

Loggings => HF Beacons => Topic started by: Desert Whooper on August 14, 2021, 0051 UTC

Title: The Desert Whooper
Post by: Desert Whooper on August 14, 2021, 0051 UTC
This is the QSL card that will be available soon to confirm your reception reports.

(https://i.ibb.co/F7nbKRt/DW-QSL-2.jpg)

The elusive Desert Whooper used to inhabit the shores of ancient Lake Mojave and is harder to spot than the more common Bigfoot creatures.  DW's lonely whoop modulates the electric charge stored in its tail and pulses an electromagnetic wave outwards.


In honor of the Desert Whoopers, the beacon was built from scratch and has a hybrid analog/Nano controller so that it can continue to whoop if the Nano fails. The transmitter is crystal controlled and features a varactor diode circuit for the upward frequency sweep.

Telemetry is as follows:

BAT is in volts DC
oTMP is in degrees F with a calibrated thermistor
iTMP is in degrees F using a digital two wire sensor within the weather tight box
PV is in milliAmps to monitor solar panel performance

The antenna is a 1/2 wave dipole oriented North/South but .15 wavelength above the desert soil to create a more vertical but omni-like pattern. The 1:1 balun is home made and measured VSWR is close to 1.1 to 1

Thank you to all who have posted logs. They are very useful!
Title: Re: The Desert Whooper
Post by: ChrisSmolinski on August 14, 2021, 1240 UTC
Awesome!  :)

And thanks for running the beacon, it's a fun DX catch.
Title: Re: The Desert Whooper
Post by: Teotwaki on August 14, 2021, 1330 UTC
I want a QSL card....   8)
Title: Re: The Desert Whooper
Post by: Desert Whooper on August 16, 2021, 2328 UTC
For the eQSL please send a detailed reception report to Desert_Whooper at protonmail.com


Please include the time, date, DW's telemetry readout, signal strength/quality, your approximate receive location, radio receiver and antenna used.

Am still searching for a deal for printed QSL postcards.
Title: Re: The Desert Whooper
Post by: Heathkit on August 17, 2021, 0152 UTC
Howdy!

Your beacon is keister kickin' for a peanut! She's a regular at >S5 in Prince George, BC and on SDR's all over western Canada. Your north signal is far better than your E-W-S, according to online SDR's.

Thank you!

73's
Title: Re: The Desert Whooper
Post by: Teotwaki on August 17, 2021, 1432 UTC
Your north signal is far better than your E-W-S, according to online SDR's.

I agree the DW beacon kicks keister, lol.

SDRs have many different antennas and noise floors that factor into the indicated S level. Time of day propagation is a big factor too.

Right now VE7GL is indicating S3 while Maui (3800 Km away to SE) and SoCal kiwis show S5. The KFS SE kiwi is indicating S9+ with its gain antenna. Sometimes I try the other KFS receivers with directional antennas and am guessing the strong S signals are due to a NVIS like signal coming down on top of the array.
Title: Re: The Desert Whooper
Post by: Teotwaki on August 17, 2021, 2101 UTC
For some near real time propagation data related to the western desert beacons try selecting point Arguello, Calif from this list
https://www.ngdc.noaa.gov/stp/IONO/rt-iono/realtime/RealTime_foF2.html

A sample plot as of this hour

(https://www.ngdc.noaa.gov/stp/IONO/rt-iono/realtime/PA836_foF2.png)

If DW's antenna has the pattern mentioned earlier such as this
(http://www.hamuniverse.com/ventdip.1.jpg)

....then based on time of day there will be reflections of near vertical and angular radiation energy
(http://kk5na.com/prop-1_files/Picture6.jpg)

Some good antenna references for longwire antennas
https://www.qsl.net/aa3rl/ant2.html
https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/qst/1993/10/page41/index.html
Title: Re: The Desert Whooper
Post by: syfr on August 20, 2021, 0007 UTC
Great posting, and I'm really glad to hear that DW is back to making serious RF! Very strong on the usual Kiwis tonight
Title: Re: The Desert Whooper
Post by: canswl on August 21, 2021, 0431 UTC
Fair reception into Masset, BC at 04:30 UTC tonight.
Title: Re: The Desert Whooper
Post by: Teotwaki on August 21, 2021, 0503 UTC
Fair reception into Masset, BC at 04:30 UTC tonight.

Holy moly!  Your receive setup is great! Is it a remote SDR?
Title: Re: The Desert Whooper
Post by: Desert Whooper on August 22, 2021, 2146 UTC
Please post up here if you requested an eQSL but did not receive it.
Title: Re: The Desert Whooper
Post by: Desert Whooper on August 22, 2021, 2154 UTC
https://www.bclnews.it/2021/08/21/the-desert-whooper-beacon-4095-65-khz/

The Desert Whooper Beacon 4095.65 KHz
In your August 4th logs a person offered some incorrect information about DW’s transmit format. For your readers’ interest, here are some technical details of the one watt beacon that provides fascinating propagation performance.

The beacon started development in November of 2020. It was built from scratch and has a hybrid controller consisting of two 555 CMOS timers to key the transmitter along with an Arduino Nano controller to generate Morse code and collect data for performance telemetry. The 555 timers will independently key the transmitter if the Nano fails for any reason. (Fortunately the Nano has functioned for 10 months without issue.) The 4.09565 MHz transmitter is crystal controlled and features a MV1403 varactor diode circuit for the upward frequency sweeps of 150 Hertz. The sweeps provide distinctive audio for the SWL’er as well as an easy to spot visual pattern on the waterfall display of Kiwi SDRs. The transmitter has 4 transistors and the final amplifier is a IRF510 MosFet followed by a low pass filter, all inside a shielded box.

The beacon is powered by a sealed lead acid battery which is kept charged with a solar panel. The battery is protected from over discharge by a low voltage disconnect (LVD) circuit that is independent of the Nano. Time has shown that the solar panel size provides good charge current even in cloudy weather and the beacon does not draw much battery power overnight.

The antenna is a 111 foot long, 1/2 wave dipole oriented North/South and it’s about 0.1 wavelength above the dry desert soil to create a more vertical but omni-like pattern. The 1:1 balun is home made and the antenna’s measured VSWR is close to 1.1 to 1

There are six cycles of DW in Morse along with 29-30 “whoops”; then the DW identification is sent along with four different telemetry numbers.

Telemetry is in slow Morse code as follows:

BAT is the battery’s voltage to tenths of a volt using a precision resistor divider and the Nano’s A2D function. Normal values range from 12.8 to 14.4 volts
OTMP is in degrees F with a calibrated 10k NTC thermistor located outdoors, about 100′ from the beacon.
ITMP is in degrees F provided by a digital one-wire DS18B20 microLAN sensor located within the weathertight equipment box. The reading runs 5 to 10 deg warmer than OTMP.
PV is given in milliAmps to monitor solar panel performance and battery charge current. Measurements are based on an INA219 current sensor board. The values of the current can range from 0 to 2000. Note that a value of 4 or 5 is just the idle current consumed by the solar controller because the battery is fully charged.

In case the Nano fails, the number of whoops can decrease from 30 down to 29 as a crude measure of rising temperatures. On some recent days the internal temperature has peaked at 120 degrees F when outside air temperature was measured at 112 degrees! The box is in shade but the electronic circuitry generates waste heat that causes the temperature rise. Monitoring the temperatures during night and day provides for some interesting deltas..

DW was officially deployed to the Western desert on February 21, 2021. It has been heard in Canada, California, Hawaii, Maryland, Utah, Arizona and many other locations. Some SWL logs can be seen here: https://www.hfunderground.com/board/index.php?board=9.0 and eQSLs are being provided.

The DW Team

Title: Re: The Desert Whooper
Post by: Heathkit on August 23, 2021, 0254 UTC
Thank you for the info, the beacon and the lovely e-QSL card!

73's
Title: Re: The Desert Whooper
Post by: Teotwaki on August 23, 2021, 1622 UTC
https://www.bclnews.it/2021/08/21/the-desert-whooper-beacon-4095-65-khz/

------ SNIP------

In case the Nano fails, the number of whoops can decrease from 30 down to 29 as a crude measure of rising temperatures.


The decreasing length of the 30th whoop had been noticed by a few of us.  The box's internal temperature effects on the analog circuitry timing makes sense.
Title: Re: The Desert Whooper
Post by: Exo on August 24, 2021, 2313 UTC
"The Desert Whooper HF Beacon"
RECEPTION REPORT by Exo.

Frequency: 4095.65 kHz
Mode: CW
Date Time: 2021AUG23 2206UTC
Signal level: -102 dBm, good readable.
Copy: DW  BAT 13.6  OTMP 98  ITMP 114  PV 4  DW
Notes: Upward frequency chirp signature whoop only on repetitive dash intervals.

AUDIO RECORDING:
 PLAY MP3 audio recording of Desert Whooper HF Beacon reception (http://hfpack.com/members/exo/4095_kHz_Desert_Whooper_HF_Beacon_2021AUG23_2206UTC_USB.mp3)

WATERFALL IMAGE:
Waterfall display image on my kiwiSDR receiving Desert Whooper HF Beacon (http://hfpack.com/members/exo/4095_kHz_Desert_Whooper_HF_Beacon_2021AUG23_2206UTC_USB.jpg)

Receiver: my home kiwiSDR on the coast of Northern California.
Antenna: Broadband dipole at 30ft.
Title: Re: The Desert Whooper
Post by: Desert Whooper on August 25, 2021, 2156 UTC
Thank you very much for the detailed report along with the picture and audio recording! You must have a low noise floor there. Great audio quality and quite a thrill to hear the Desert Whooper through your SDR

The eQSL will be in your PM inbox in a minute

DW
Title: Re: The Desert Whooper
Post by: Exo on August 26, 2021, 0110 UTC
The Desert Whooper,

Thank you very much for the wonderful e-QSL card!
The Desert Whooper is by far one of the strongest and most interesting HF beacons of its kind that I've copied in the past decade here.
The use of CW telemetry for temperature, power, and solar charge status is brilliant.
Best wishes.

Exo

Thank you very much for the detailed report along with the picture and audio recording! You must have a low noise floor there. Great audio quality and quite a thrill to hear the Desert Whooper through your SDR

The eQSL will be in your PM inbox in a minute

DW
Title: Re: The Desert Whooper
Post by: syfr on August 26, 2021, 2227 UTC
Will renew my efforts for a direct reception when T-storm season is over. Thanks for the really fun DX target!
Title: Re: The Desert Whooper
Post by: Teotwaki on September 02, 2021, 0006 UTC
I just discovered this new DW video today

https://youtu.be/7_CAxPhgWAw
Title: Re: The Desert Whooper
Post by: Teotwaki on September 02, 2021, 1515 UTC
Another new video  https://youtu.be/LuP5GD1CLEQ
Title: Re: The Desert Whooper
Post by: HRO500 on September 05, 2021, 0427 UTC
Heard DW just fine here in the San Francisco area.
Date:  9/5/2021  Time:  0421 UTC
Frequency:  4095.489 CW, 600 Hz BW, BFO 685 Hz
Signal strength S-6 to S-7
Lots of whoops!
BAT:  13.1
OTMP:  91
ITMP: 96
PV:  1
Receiver:  Ten Tec  RX-340
Antenna:  100 meter horizontal loop

Would love to get your eQSL.  It's a very cool beacon.
-- 73 from HRO500
Title: Re: The Desert Whooper
Post by: Teotwaki on September 05, 2021, 0706 UTC
In the first few messages there is an email address for eQSL requests
Title: Re: The Desert Whooper
Post by: Grounded_Grid on October 09, 2021, 1043 UTC
I can't believe how well this beacon gets out for only being one watt.

I can pretty reliably hear it's whoop's and ID from upstate NY, but it's far enough below the noise
for me that the telemetry is too hard to copy.  Around 10:00Z this morning I did catch the battery
voltage of 12.9 though.

Hopefully the noise will drop far enough this winter I can copy the telemetry.

Thanks for a fun beacon!!
Title: Re: The Desert Whooper
Post by: Heathkit on October 10, 2021, 0152 UTC
I can pretty reliably hear it's whoop's and ID from upstate NY...

Wow! That's pretty good for a watt.

Given it was logged in HI, northern Canada and all over the US, before the op clued us in, I guessed a good 10 or 15W. I would LOVE to see the perfect antenna/matching/ground system he's got on it :D

73's
Title: Re: The Desert Whooper
Post by: Teotwaki on October 12, 2021, 0526 UTC
Now that the weather has cooled off I can sum up a couple of data points about the whoops

When DW first was heard at full strength back in February there were 30 whoops on each cycle.

As the weather heated up someone here noted the 30th whoop was shorter. Sure enough, as temps climbed upwards that 30th whoop all but disappeared.

Tonight DW reported the internal temp at 63 and the 30th whoop seems whole again.
Title: Re: The Desert Whooper
Post by: Dave Richards on October 13, 2021, 0609 UTC
Tonight DW reported the internal temp at 63 and the 30th whoop seems whole again.

That observation shows quite remarkable attention to detail, Teotwaki.
Title: Re: The Desert Whooper
Post by: Teotwaki on October 13, 2021, 1454 UTC
That observation shows quite remarkable attention to detail, Teotwaki.

Thanks Dave. It all sprang from a discussion between Syfr and myself at the end of March. He also pays close attention to interesting details. It’s been a long wait since March to get another data point!

Jim
Title: Re: The Desert Whooper
Post by: Finman on October 18, 2021, 1526 UTC
Copied the Desert Whooper early this morning, around 09:30 UTC, but again, couldn't copy the telemetry due to the noise level.

Title: Re: The Desert Whooper
Post by: Desert Whooper on October 27, 2021, 1852 UTC

Wow! That's pretty good for a watt.  I would LOVE to see the perfect antenna/matching/ground system he's got on it :D

A lot of time was spent trying to determine how much transmit power was appropriate. After extensive research about QRP rigs one watt seemed appropriate.  Next antenna efficiency and pattern were focused upon.

The desert soil is very rocky and dry so the antenna is hung relatively low to achieve a 50 ohm match close to 1:1 vswr. From the ideal free space length the antenna was shortened 92" to achieve the match. There are no additional ground rods or counterpoise elements strung out beneath the antenna.

Balun efficiency was also  looked into and a simple 1:1 "transformer" of coax wound on a large core had the lowest loss.
Title: Re: The Desert Whooper
Post by: Heathkit on October 29, 2021, 1638 UTC
Thank you for that info!

73's