Mike ZS6MSW came up with a brilliant idea that kind of falls in line with the requirements of accurate logging much like RaDAR.
His idea was to make CW QSO’s fun and to expand on the standard exchanges a little into short purposeful QSO’s. We placed an order for food with each other, logging the ordered foods in the comments column on the RaDAR Sport Online logbook. Grids were exchanged as well which could be seen as a delivery address and falls in line with what the world is experiencing through Covid-19 that we “accept deliveries”.
Arthur ZS5DUV introduced some unexpected responses when Eddie ZS6BNE ordered Chicken hearts saying he does not have them on the menu and Eddie had to change his order. This was incredible fun. enjoyed by none other than the CW fraternity in ZS. It gave CW and accurate exchanges a purpose.
The “Evaluator” was used to evaluate the exercise and the accuracy of taking orders. Mike ZS6MSW was called by Frank ZS6FN while Mike was entering his log which may be seen too as passing the order to the kitchen. Mike kindly asked Frank to wait. When all was clear they exchanged their orders!
This was close to real world information exchange and done entirely using Morse Code!
1.1 The RaDAR “Challenge” is a unique event aimed at promoting the use of Rapidly Deployable Amateur Radio stations. Options (Fixed, Field or Moving) may be changed at any time during the challenges. The points system is so structured as to encourage portable RaDAR operations especially moveable RaDAR stations.
1.2 RaDAR operators are encouraged to be self-sufficient during each challenge, with not only power supply and communications equipment but food, water, protective clothing and shelter.
1.3 The introduction of various categories starting from November 2021 (Test phase).
Category A – A FULL twenty four hour RaDAR Challenge.
Category B – The standard RaDAR challenge. It’s up to each individual to plan his / her MAXIMUM, SINGLE PERIOD, FOUR HOUR ops.
Category C – A 2 hour RaDAR Sport sprint, starting time 14:00 LOCAL TIME. This is a physically demanding challenge.
Category D – A RaDAR Chaser station. Without these stations RaDAR operators will find difficulty in maintaining quick QSO’s per deployment.
Please ensure that you mark your category correctly when entering or editing your logs in the online logbook.
Once a challenge is completed by a RaDAR Challenge participant, there is no harm in becoming a Category D Chaser station. Monitoring the online logbook in real time will provide clues to where to find the activity worldwide.
All logs are to be recorded using the unique online logbook. A PIN is required for access and must be arranged a week ahead of the challenges. Ideally every RaDAR operator should be possesion of his own PIN to be able to log online. Contact Eddie, ZS6BNE via email on firstname.lastname@example.org. The online logbook can be found at :
As in the past one point was allocated for each of the five QSO’s per deployment. Now if the log is matched on the system with another then both stations get credit for the QSO otherwise the logged QSO only has a one point value. As this concept will grow so will the accurate logging from all stations become a reality. This has been proven during the development and testing of the online community logbook.
2. Dates and Times
2.1 RaDAR operators define their own categories.. He / she should consider propagation with the ultimate goal of inter-continental RaDAR to RaDAR communications in mind.
2.2 00:00 UTC to 23:59 UTC on Saturday 3 April 2021
2.3 00:00 UTC to 23:59 UTC on Saturday 10 July 2021
2.4 00:00 UTC to 23:59 UTC on Saturday 6 November 2021.
3. Bands and Modes
3.1 All amateur bands are allowed including cross band contacts via amateur radio satellites. Modes – CW, SSB, FM or any legal amateur radio digital mode (Except modes like FT8, preferably keyboard to keyboard modes like PSK31 where the operator is directly responsible for the information exchange).
The WARC bands are INCLUDED – The RaDAR Challenge is not considered to be a contest but an individual challenge with a low QSO count and a simulation of emergency situations. 17m is a popular band to use.
3.2 QSOs via terrestrial FM repeaters should preferably NOT be used for the purpose of the challenge.
5.1 The RaDAR challenge requires more than a minimalistic information exchange. Accurate information exchange is considered more important than a large QSO count. Callsign, Name, RS (T) report and Grid locator. The grid locator of six characters is acceptable but should preferably be accurate to 8 or 10 characters for higher position accuracy (especially for moving RaDAR stations). If the other station is unable or unwilling to give a grid location then the name of his town will suffice.
One point per QSO. Individual QSOs could be per band, per satellite, per grid location. If the other station also logs the contact accurately on the online logbook, it is then considered to be a RaDAR to RaDAR contact and the bonus points then come into play.
The online logbook has a facility for evaluating the accuracy of logs. For RaDAR even the grid exchanges need to be exact. If the times are within five minutes, date, frequency and grids match then two bonus points are awarded to both stations. This is done by the RaDAR Challenge online Evaluator.
If the moving RaDAR station has moved the required distance contact can be made with a previously worked station again. Suggestions have been made to call CQ including grid location, for example CQ RaDAR from grid KG34ACXXYY, to help chasers determine whether it is possible for a new contact with a previously worked moving RaDAR station.
The number of transitions that took place will be considered a multiplier for the total scores achieved through the five contacts per deployment point.
7. RaDAR transisiton options and multipliers
7.1 The following multipliers are applicable to determine the final score. If the mode of transport changes were made during the challenge, then calculations take place accordingly. Ensure your mode of transport is correctly selected when entering your log into the online logbook.
x 1 – RaDAR Fixed station (in a building away from home)
x 2 – RaDAR Field station (camping)
x 3 – Moving RaDAR station – see modes of transport below.
7.2 Modes of transport and required movement distances (moving RaDAR stations only)
Vehicles, motorcycles and motorboats (motorized transport) – 6 km.
Note: Motorized transport is only allowed for the twenty four and four hour challenges and not for the two hour RaDAR Sport sprint. The RaDAR Sport sprint is more of a physical challenge.
Bicycles – 2 km.
On foot and paddle canoes – 1 km.
Wheelchairs – 500 m (The four hour challenge only).
7.3 Aeronautical mobile stations are considered moving stations and can communicate at any convenient time.
7.4 Moving RaDAR stations need to make five QSOs before moving to the next deployment point thereafter they are required to move to their next destination. The move needs to cover the required distance before further contacts can be made. This requirement tests the ability to rapidly and successfully re-deploy your amateur radio station. If it be gentlemanly to make further QSOs before moving, then please feel free to do so but the QSOs in excess of five per deployment point cannot be counted for points. For simplicity, log only the five required contacts per deployment point. It will make it easier to follow the activity of moving stations in real time.
8. Log Sheets
8.1 Log sheets must be entered online or uploaded to the online log using ADIF. Logs should preferably entered directly after each QSO (See Note). End of QSO times are also the most accurate to log. If ADIF uploads are done after using a logging program it will be necessary to do final edits of the uploaded logs as ADIF does not cater for all RaDAR related fields. It is no longer necessary to submit a log as it already exists in a database behind the online logbook. This is what makes the online logbook quite unique.
Note: Ideally the logs should be entered as quickly as possible that activity can be monitored in real time but it is understandable if this is not possible. Some deployments may be out of range for Internet access. In this case enter or upload your logs at your earliest convenience preferably not later than one week after the challenge. An online evaluation can be done at any time.
Through the QSO Today virtual expo I introduced the idea of RaDAR Sport. Since then I have done much to contribute towards the idea, in ZS at least. The RaDAR Challenge has been with us for many years, unusual ham radio fun. It was designed to cover a whole twenty four hours with the hope of international RaDAR to RaDAR communications. It was mostly touch and go with no defined times, modes or frequencies and usually local groups made arrangements to meet somewhere, somehow on the bands.
I want to take RaDAR to the next step starting in November as a trial run for future years. The three dates per year will remain but the times will become shorter and planned using UTC as a reference time. My suggestion is that the RaDAR Sport Challenges start at 14:00 local time in whatever time zone you live and the end time16:00 local. That gives a full two hours to make as many deployments as possible. The requirement is still five QSO’s per deployment point.
Individuals or teams of individuals will line up at the start time. No motorised transport, you are either on your feet, on a bicycle or in a canoe. Travel distances for on foot and canoes, as always, one kilometer and two kilometers if travelling by bicycle. This allows us to compare apples with apples.
During the past few weeks I have been developing the online RaDAR Sport log and has been tested mainly by the CW guys in ZS. It caters for RaDAR Grid exchanges. This online system will need to be used during the RaDAR Sport challenges. It will allow the world to see the activities taking place throughout the world and chasers can now have better opportunities to work RaDAR Sport participants and they will have a general idea where the stations are active having international access to the online logbook.
I have also built an Evaluator so each period can be evaluated separately or an evaluation of the international 24 hour period can be done in literally, seconds. The Evaluator has been tested and has become very popular. An option to do the RaDAR Sport evaluations still needs to be written but the infrastructure is now there to evaluate just about any type of contest. In the case of RaDAR, accurate grid exchanges are critical. No points for unmatched grids or incorrect times.
Keeps these ideas in mind and try to do the November challenge according to these rules.
Quite a bit of organising took place before this challenge. The idea was to have a support system in the way of monitor stations distributed throughout ZS on CW and SSB. The monitor stations were designated unique calling frequencies on 40m.
The idea of monitor stations stemmed from a suggestion I made during the recent QSO Today virtual expo so the concept for RaDAR Sport was successfully tested within this RaDAR Challenge.
For quite a few days I used WSPR to estimate a suitable time of day for the challenge and we decided on 14:00 to 18:00 local time (CAT). Not all stations took part in this particular time frame which of course is still quite acceptable within RaDAR. 40m can change within minutes I have found but it was there for us that afternoon. Propagation conditions were quite suitable.
A log sent in by Christi ZS4CGR who was a SSB monitot station. Moving stations could easily make contact with these station to make up their required five QSO’s so they could move to their next location. Ludwig ZS5CN and Rudi ZS2M were also there on every call. Great to he Frank ZS6FN too. CW certainly shined here in South Africa this day.
This was my log, my ADIF Data uploaded to qrz dot com. It was undoubtedly the best RaDAR Challeng to date!
I carried my Icom IC-7200 just so I was able to do SSB and push a little more power than five Watts – Just in case. I had a newly built dipole which wasn’t field tested yet and I paid dearly for that and had to do field repairs on two occasions. I also carried two 7 A/Hr SLABS in parallel as a D.C. power source.
Sid ZS5AYC and Adele ZS5APT, our regular SOTA activators and RaDAR Challenge participants too part in the challenge again too.
I had built a QRP Labs U3S and run it on 40m and 20m. My main interest is in NVIS communications (Near Vertical Incindence Skywave). Many years back I visited a facility in Hermanus, South Africa where they test for various HF propagation conditions. The term Ionosonde comes to mind.
Well I made my own system that seems to work very well using WSPR as the source on the U3S and WSJT-X together with a SDR-IQ as the receiver. Allow me to present some further detail.
In KG34ac (Lichtenburg) I run the U3S using a 40m / 20m trap inverted vee. I built the simple traps myself on tiny pieces of PCB using a 30 turn winding on a red toroid with a parallel 47 pF capacitor. On 40m the U3S puts out 200 mW and on 20m, 50 mW approximately. The WSPR sequence is repeated every six minutes.
In KG34ac (Molopo), 29 km away as the crow flies I run WSJT-X in WSPR mode talking indirectly via virtual audio (Software) and Spectravue (RF Space’s SDR software) to the SDR-IQ SDR HF receiver usually used as a CW monitor for the RBN (Reverse Beacon Network) when appropriate..
These two options allow some pretty interesting observations. I use WSPRD at http://wsprd.vk7jj.com/ to accumulate the data and create an appropriate graph from that data using LIBRE Calc (Freeware office software).
The results coincide with real world propagation opportunities for NVIS communications. I drew this graph from recent data.
Now that’s using WSPR for a purpose! The SNR values are usually well into negative values for example -27 or nothing at all. Anything above the zero line is a very good indicator that suitable conditions exist.
In South Africa we are experiencing a lot of load shedding, two and a half hours at a time sometimes twice a day! It so happened too when I was supposed to join in via Airmeet on my pre submitted RaDAR presentation hosted by QSO Today’s virtual expo.
In between these power failures I really battled to navigate the website and once I got reasonably familiar with the layout I was unable to get my video and microphone to work so it wouldn’t have helped to even implement emergency power and get online.
Ed DD5LP was the host for the session and he sent me a mail later that he was able to successfully broadcast the presentation. In effect, Ed saved the day. Thank you Ed! Ed sent me some Q&A’s which I will try to reply to here on my blog and can be distributed easily.
Ralph KR6AI from what I’ve seen it depends on the environment and the target area. I’ve seen hams’s using Alex loops, verticals near salt water and end feds. I prefer end feds as it is easy to deploy and here in South Africa we are many hops away from DX so I usually concentrate on NVIS communications.
Theodore KD2TGO the official RaDAR website is one I maintain and can be accessed at http://www.radarops.co.za however RaDAR is an experience and many use social media platforms to share experiences and many videos are available on You Tube. The more we become RaDAR active internationally the more we can see the experience of others and also share our own experiences in the same way.
Usually low power equipment like a KX2 / KX3 / FT-817 and even the new QRP Labs QCX Mini. Antennas are usually made of wire. For satellite communications I use a TH-D7A(g) which has a duplex facility. Antennas for satellite communications can be home brewed very easily or you can use the popular makes like those from Arrow antennas.
Jim N7RCS I would love to write an article. I would need some contact information and guidelines.
Dennis KD9KMK I did one challenge in a canoe. It was quite challenging but one can row to a point, climb out and deploy your station after moving a kilometer. Unfortunately our river dried up for reasons beyond our control so my canoe is no longer used. It was a fun exercise though!
Bruce W1EJC the band of choice would be the one giving the best propagation at the time. I usually spend my four hours on 40m and occasionally do satellite deployments too.
If I had my way I’d do all my contacts on CW. Here in South Africa we have only a few CW operators and around ten regulars. Much of the action is on SSB which limits the usability of the radios like the QCX mini which is CW only. Our CW group is growing much through the driving force from Mike ZS6MSW so hopefully in the future we may see a CW only four hour challenge. That would be awesome!
Much work went into the QSO Today virtual expo, the many presenters and the organisers must have had a heavy weight on their shoulders this past weekend. The technology I think was really awesome but complicated. I think there were many teething problems but let’s continue to support Eric 4Z1UG in ironing out the problems that the next expo be more familiar. I felt lost at times and I come from an IT background!
I had built the QRP Labs U3S WSPR transmitter and expanded it for two bands namely 40m and 20m. My interest is 40m as most of my RaDAR operaions take place locally although during the challenges it’s always good to cross the oceans and access other continents and make contact with other RaDAR operators around the world.
For quite some time (A few weeks) I have been WSPR’ing from my RaDAR playground in KG34ac but I started to get irritated by the slight QRM I was experiencing on my CCTV cameras which I use as “The poor man’s trail camera”. Seeing my grandson was returning to school after almost a year attending on line schooling due to Covid-19 my wife and Eduan had to go back to town in Lichtenburg and only join me on weekends again. I had to do a few chores there yesterday and took the U3S into town and set it up there. I had built a trap dipole for the purpose and got it up at about five meters above ground in an inverted vee format. The antenna was fed with a length of RG215, better than it was here at home.
I had to update my 6 character TX grid to KG33bu on the WSPR database after I found it was only registering 4 characters on the WSPR database. I had conflicts with duplicate call signs in different locations so the RX side I renamed to ZS6BNE/p which is what it is actually. I use a RF Space SDR-IQ SDR running on its software typically Spectravue. I use a virtual audio cable (Software) to channel the audio to WSJT-X running in WSPR mode. Here too I have an inverted vee on 40m for reception. My main concern obviously is 40m.
This opened up some interesting facilities. ZS6BNE TX in KG33bu and around 30 km away as the crow flies the ZS6BNE/p RX in KG34ac. This is my own NVIS alert / testing facility and has already shown some interesting results!
As suggested by a friend on our local WSPR WhatsApp group I use http://wsprd.vk7jj.com/ to do queries on the WSPR data. From this data I intend pulling it into Libre-Calc and drawing graphs from the results. Here you can clearly see a NVIS opening and to prove it I made contact with Andy ZS6ADY who is usually skip to me!
I’m looking forward to those graphs and seeing the interesting results!
Andre ZS6CO was the first to submit a log for the November 2020 RaDAR Challenge. Andre worked from home as a fixed station and filled an important role. He worked three moving RaDAR stations, ZS5AYC, ZS6BNE and ZS6MSW. This support is what RaDAR operator like to see.
Tjaart ZS3DR ran a mobile station from his Landcruiser. Tjaart enjoyed the RaDAR movements. He managed to activate seven individual grid locations.
Christi ZS4CGR a supporter of many ham radio activities also joined in on the RaDAR Challenge. His plan was to travel using his bicycle but I believe the wind was excessive so he travelled using his bakkie. Christi activated eight different grid locations.
Andy DL2DVE joined in the RaDAR Challenge again. Andy wrote, “For the 7th Nov 2020 challenge I decided to walk, and selected a few places beforehand close to my QTH. Main target was to contact other RaDAR operators and to try R2R DX, so I took with me not only the IC-706 (100W) and the 2m long (high) Vertical, but also the 10m long vertical EFHW for 20m with a 12m mast. Spent quite some time to figure out how to contact M0NOM after I left house without e-mail… Finally we got a very nice R2R QSO on 20m SSB. Could hear N4KGL on 14.062 with 229…339 with the short antenna – this motivated me to assemble the large one. It was my priority so I gave up to walk to the 3rd site. But could not copy Greg at his 2nd stop on 20m SSB as there was European QRM. Have two sites activated (less than my plan), but the main target R2R was achieved, with Mark M0NOM/P. Temp was 5 deg C, no rain. Two deployments, one EU-R2R and one DX-Contact to US, resulting in 60 Points. 3x (2 x 5 +5 +5). 73 Andy DL2DVE”
Hoping 2021 will see the dark clouds of 2020 disappearing. 73 and hope to hear you all on the bands soon.
Imagine each division in ZS will have a dedicated RTS (RaDAR Traffic station) for the four hour duration of a RaDAR Challenge. Let’s say HF only, 40m. A moving RaDAR station will call on a dedicated RTS frequency, say for ZS1 7.085 MHz, “ZS1RTS ZS6BNE RaDAR Traffic”. No answer, switch to 7.090 for ZS5. “ZS5RTS ZS6BNE RaDAR Traffic”. ZS5 RTS station will reply, “ZS6BNE ZS5RTS Send”. “ZS5RTS ZS6BNE Name Echo Delta Delta India Echo Grid Kilo Golf Three Four Alpha Charlie One Niner Foxtrot India”. “ZS6BNE ZS5RTS Confirm grid Kilo Golf Three Four Alpha Charlie One Niner Foxtrot India” If all OK, “ZS6BNE” (To sign out). In this case there is no two way exchange as the fixed RTS station operators and Grids are known. Once the moving RaDAR operator has five successful QSO’s he / she can move for redeployment elsewhere. There can however be a dedicated watering hole frequency for R2R (RaDAR to RaDAR) QSO’s if there is such a chance of a successful TWO way exchange between RaDAR operators. The first QSO having five bonus points. A QSO with a fixed RTS station counts as one point. …….. and so on.
Imagine country wide about forty hams taking part in the RADIO SPORT of RaDAR. Each chooses his own method vs distance of transport but he / she is free to change the method of transport at any time during the challenge – walk, bicycle, canoe, quad, SUV. They each have their individual routes planned, their tactic. Propagation will have minimal effect with the RTS stations distributed amongst each province / division. At the end of the four hour challenge period the logs are submitted to a website where the results are computed online giving the results. Prizes could be a year’s free SARL membership for the top contender etc. Naturally each contender has his / her own individual plan. Like Sid last weekend could have walked 1km faster than he could drive 6 km in his vehicle after the SOTA activation. Walking in that case could have been a better choice.
I was thinking it would be a little tough but really if out of the five QSO’s , one was incorrect then that whole deployment section of 5 contacts become NULL because only four out of the five could be counted ….. It actually makes sense to be that strict because in RaDAR, accuracy is worth more than a high QSO count. In my example way above where the RTS station confirms the grid it is quite important that he does that both stations do a final check for accuracy before continuing …..
Something to think about and any country in the world could take part in a similar way, anytime!
Sid ZS5AYC and his wife Adele ZS5APT are regular SOTA activators and take part in all the RaDAR Challenges too. This is Sid’s report ……
Saturday morning for Adele and I started at 04:45, the summit we had decide to activate was between Kokstad and Underberg, we had deciding to first activate the summit ZS/KN-145 Belfast and then start the RaDAR challenge to coincide with the other RaDAR operators, this was the first time in South Africa that there would be so many RaDAR ops and we were excited to be part of the challenge.
We misjudged the time it would take to reach the summit and after hiking up we were 19 minutes behind schedule. After the first few minutes we realized that this would have to be our first RaDAR station, because the temperature was already 26°, we needed to keep operating because the chasers were piling up, within an hour we had made 17 contacts, with Eddie ZS6BNE being our first RaDAR to RaDAR contact.
I set off for my kilometre walk, but once we had descended our friends asked if we were still up on the summit, we then went back into the activation zone and set up to make contact with them, unfortunately they couldn’t hear us, so we broke station, and I continued with my walk, with Adele making her way down in the Toyota.
We quickly set up station and started calling, making 4 contacts, one with Denise (ZS1DS) who was participating in the Day of the YL.
As we had spent so much time activating the summt, we decided to drive 6km, big mistake ……. the trip down on the farm rode took us nearly an hour to reach the 6km distance, I would have walked the 1km faster.
After the 5 contacts we drove the next 6 kilometres but by the time we had set up we only had 5 minutes to make 5 contacts. We managed 3 contacts before our time was up.
All in all we had so much fun, making contact with three of the other RaDAR stations.
Looking forward to the RaDAR Challenge in April 2021.