What happened to the ZS6SRC Pico Balloon?

The Secunda Radio Club launched a Pico balloon at the Trichardt Model Aircraft Club on Saturday 24 May 2025.  Click HERE for more information on the balloon project.

Today is the 27 May 2025 and the latest dashboard indication is that the balloon  was last seen: 2 days, 17 hours, 22 mins ago.  It would appear that the balloon is stationary as indicated on the dashboard images.  If anybody knows if the balloon is still active and in the air we would like to hear from you.  Info can be forwarded by clicking HERE.

Images:  Click on images for larger view.

Building Low Budget Antennas - QRP End Fed Half Wave Antenna - Project 7 (Part 1)

I continue with the series "Building Low Budget Antennas" for Radio Amateurs. Nothing fancy .... no just simple low budget antennas!

In this article I will be looking at building a End Fed Halve Wave Antenna for 40 to 10 Meters. Now I know there are thousands of ways to construct this antenna, but how cheap can you build one? R10, R50 or R100. You decide how much such an antenna will cost. 

In Part 1 I will describe how I constructed the 49:1 Balun for this antenna.  In Part 2 we will be looking at the antenna wire, Nano VNA readings and the results when using this antenna.

General Specifications:

Resonant Frequency: 10.130 Mhz

Frequency Span: 7 - 28 Mhz

Antenna Impedance: 50 Ohm or very close to 50 Ohm

Use:  General HF use but for now WSPR on 20 Meters

Enough said let's start building the QRP EFHW 49:1 Balun. 

Materials I used:

1 x PL239 Socket Connector with two brass bolts and nuts

1 x Project Box

2 x Stainless Steel bolts, 4 x nuts and 2 x wing-nuts and 2 washers

1 x 1.5 Meter (1.5 mm) Copper Wire 

1 x F82-43 Toroid

1 x 100pf 1kw Capacitor 

2 x Electrical Lugs

1 x 2K7 Resistor to test the 49:1 Balun

Odds and Sods:

Cable Ties

Silicon Sealant

Insulation Tape

Solder

Solder Paste

5 -10 m Coax Cable (RG58CU Mil Spec) 50 ohm with 2 x Connectors

Self Amalgamating Electrical Tape

Tools:

Soldering Iron

Sharp Utility Knife

Screw Drivers (Small flat + Star)

Test Equipment:

HF Radio

SWR Meter

Antenna Analyzer (If you have one but not compulsory)

Coax Patch Leads

Mast (Non conductive)

Power Supply or Battery for Radio

Building the Balun and Antenna:

I am not going to go into detail how I constructed my version of this balun and antenna as there is more than enough info on the Internet. Google is your friend. 

Here are two sites you can visit that might be of assistance to you if you want to construct this antenna.

Manual impedance transformer for 250 watts End Fed Antenna’s

Build an End-Fed Half-Wave Antenna From a Kit

I used what I had available on my shelves and in the junk box and came up with my version of the 49:1 balun.

The 49:1 Balun diagram:

Constructing the balun is straight forward and there are many videos available on how to wind the toroid.  Just one word about the 100 pF capacitor.  Is it really necessary? If you have a 100 pf 2 kV available then you can install it.  If you run high power you will need at least a 15 kV capacitor. For 20, 30 and 40 meters you do not need a capacitor.  However for 17 meters you will need a capacitor to flatten and lowering the SWR curve through to 10 meters.

Preliminary Test Results:

To test the balun before adding the wire and counter poise I used a 2K7 resistor on the ground of the coax connector and antenna connection.  The attached NanoVNA images provide info on the results I obtained from the balun.  I am sure the SWR readings will change once I add the antenna wire to the balun.  The height and closeness of objects will also play a roll.

Finally:  In Part 2 I will be looking at the performance the antenna and will also do more experiments and measurements using the NanoVNA and WSPR - Lookout for Part 2!

Images:  Click on images for larger view.

Part 2 to follow soon.

Refined study pinpoints location of Malaysian Missing Flight MH370?

 

A new report into the disappearance of MH370 has pinpointed a location further north than first thought.

The report is a refined and updated study using the revolutionary WSPRnet tracking technology.

It is authored by aerospace engineer Richard Godfrey and Dr Hannes Coetzee (ZS6BZP).

The report states: “In the previous paper titled MH370 GDTAAA WSPRnet Analysis Flight Path Report dated 31st December 2021, we tracked MH370 from take off to the end of the flight.

“Since the previous paper was published we have made a number of improvements in the GDTAAA software and WSPRnet data processing.

“One of the key changes is a tighter definition of the WSPRnet SNR anomalies.

The refined flight path has many twists and turns and the authors say they “have presented evidence that the pilot may have been disoriented, which can be caused by hypoxia.”

READ: WSPRnet explain

READ: MH370: The extraordinary debris trail across the Indian Ocean 

READ: MH370: chronology of major events 

The report states that MH370 crashed between 00:22 UTC and 00:27 UTC, which is 8.22 am and 8.27 am local time.

It adds that at 8.22 am the position from the WSPRnet analysis was estimated to be 30.00°S 98.70°E.

At 8:26 am the position from the WSPRnet analysis was estimated to be 30.57°S 98.75°E.

Read the full report here.

The crash location is further north than previously thought and up to 42 nmiles South East of the 7thArc.

The yellow lines mark the location

The report also states that “we have presented evidence that there was an active pilot until the end of the MH370 flight.”

Famous debris hunter Blaine Gibson, who has found much of the MH 370 debris said: “Your [Mr Godfrey’s] statement and the paper are both excellent ! The WSPR crash site fits within Prof. Pattiaratchi’s UWA drift analysis, which identified the origin of MH 370 debris between 28°S and 33°S. That drift analysis accurately predicted where and when MH 370 debris would arrive, and led me to find and collect from local people many pieces of the plane. Search On, and let’s find the rest of the plane, the truth, and the proof!”

Recognition:  airlineratings.com 

ED ZS1I -

Why post this here.  Well amateur radio is involved in the search.  HERE is the original video that I posted awhile ago.  Would it not be remarkable if MH370 can be found using WSPR signals at the time of disappearance?   It would be awesome if amateur radio and other information could solve this mystery.

Let's see what happens.  Updates will follow as and when I receive them.

 

Flight OE-FGR GDTAAA WSPRnet Analysis - Case Study - 28th October 2022

 

Flight OE-FGR GDTAAA WSPRnet Analysis
Case Study
by Richard Godfrey and Dr. Hannes Coetzee (ZS6BZP)
28th October 2022

In previous papers we have successfully detected and tracked both large aircraft such as a
Boeing 777-300ER [1] and small aircraft such as a Diamond DA40 [2]. In this paper we analyse the
tragic flight of a Cessna 551 Citation II/SP registration OE-FGR, which crashed after fuel
exhaustion into the Baltic Sea off the coast of Latvia on Sunday 4th September 2022.
The aircraft departed Jerez-La Parra Airport (XRY) in Spain at 12:56 UTC, en route to Cologne
Airport (CGN) in Germany. The aircraft continued at FL360 through German and Swedish
airspace. The aircraft was not reachable by air traffic control authorities for some time. French,
German and Danish fighter jets were in turn dispatched to follow the aircraft. Reportedly the pilots
could not see anyone in the cockpit of the aircraft. 

The purpose of this case study is to show how aircraft can be detected and tracked both in the
cruise phase of a flight in straight and level flight as well as in the descent phase whilst
descending and turning.

The dimensions of the Cessna 551 Citation II/SP are as follows. The length is 14.5 m, the wing
span is 15.9 m and the wing area is 31.8 m2. This is much smaller than the Boeing 777-200ER, the
aircraft operating the flight MH370, which had a length of 63.7 m, a wing span of 60.9 m and a
wing area of 427.8 m2. The wing area of this Cessna was 7.4% of that of MH370. The flight of
MH370 was detected and tracked using WSPR technology and is the subject of three previous
papers on the initial Flight Path Report (2021) [3], the Technical Report (2022) [4] and the final
MH370 Detection and Tracking Report (2022) [5].

Download the full Case Study HERE

Recognition to:  Richard Godfrey and Dr. Hannes Coetzee (ZS6BZP)

MH370: New Research Paper Confirms WSPRnet Tracking Technology

Two previous postings on the GRHub Network Blog refers.  Read more HERE and HERE

A new paper (see next post) into the recent loss of a Cessna 551 Citation has confirmed the MH370 WSPRnet tracking which is expected to lead to a new search for the Malaysia Airlines Boeing 777 that disappeared in 2014, in 2023/4.

The 142-page paper authored by Richard Godfrey and Hannes Coetzee states that “in previous papers, we have successfully detected and tracked both large aircraft such as a Boeing 777-300ER and small aircraft such as a Diamond DA40. In this paper, we analyse the tragic flight of a Cessna 551 Citation II/SP registration OE-FGR, which crashed after fuel exhaustion into the Baltic Sea off the coast of Latvia on Sunday 4th September 2022.”

This case study is similar to the tragic flight of MH370 in as much as the aircraft flew until fuel exhaustion and then crashed into the sea. The airspace around the aircraft was cleared of other air traffic over the Baltic Sea with the exception of the fighter jet assigned to follow and observe the Cessna.

The authors said that they “have demonstrated how aircraft can be detected and tracked both in the cruise phase of a flight in straight and level flight, as well as in the descent phase whilst descending and turning.

The authors also investigated alternative hypotheses and anomalies in relationship to WSPRnet links and said that while the WSPRnet data was noisy, with care it is possible to extract useful information.

They add: “The analysis in the report supports our previous belief that using WSPRnet data to detect and track MH370 together with the Boeing 777-200ER performance data and the Inmarsat satellite data provides a reliable method to determine the crash location.

“The results of the WSPR-based analysis align with previous work by the Oceanographer Prof. Charitha Pattiaratchi of the University of Western Australia who has performed a drift analysis of the floating debris found from MH370.

“We recommend further studies applying the same approach to quantifying the performance of WSPRnet detection and tracking to other aircraft (and in particular the Boeing 777 which was used for the MH370 flight) over longer time periods in the Indian Ocean region.”

The authors also said: “We are very grateful to Prof. Simon Maskell of Liverpool University for reviewing our work and making a number of helpful comments and suggestions on our approach and the presentation of our results.

“We would like to thank Prof. Charitha Pattiaratchi for his MH370 oceanographic drift analysis and Blaine Gibson and many others who have recovered MH370 floating debris items. We are very grateful to Ocean Infinity for reviewing our work and proposing a plan to search again for MH370 in 2023 or 2024.

“We dedicate this work to the MH370 families and friends and acknowledge their great personal loss and tireless efforts to achieve a new search for the wreckage of MH370.”

Recognition to: airlineratings.com