RaDAR – The nitty gritty facts


RaDAR has awakened the excitement of many hams throughout the world. Some shy away from it but keep one eye open and are aware of it’s “dangerous” potential. Exciting videos have been made, “The radio ham” by ZS6BNE and his son Edwill was the start. Many hams throughout the world are now making their own exciting videos on RaDAR. Indeed it flies the flag of good example to newcomers to this amazing technology, ham radio.

RaDAR changes the way hams see their purpose in the world of amateur radio, there must be a purpose, right? RaDAR offers an alternative to large sophisticated fixed radio stations to those that are movable, in fact the very essence of RaDAR is movement. It tests the ability to set up and successfully man a radio station under difficult conditions, conditions that one day may take many by surprise except the highly trained and practised RaDAR operator.

RaDAR makes the radio operator aware of what is required to to be an effective communicator, a healthy and fit individual that adds simple survival skills to his / her portfolio. RaDAR is forever evolving, essentially different in many ways. It promotes many forms of communications from morse code to advanced computerised digital modes. RaDAR promotes the use of space technology in every way possible. RaDAR is, daring to be different.


RaDAR – ZS4 One hour sprint

An hour to go, time to make my way into the field.


This was an ideal opportunity to test the kit with in pack battery supply, the Rossi. I store it at the base of the pack with a sponge between it and the rig’s camera bag to absorb shock while traveling.

Not too far from home, around 100 meters in fact (Endomondo logged 3.5 kilometers getting there), I put up the ZS6BKW open wire fed dipole using my painters poles for the mast.


Deployment times were fast but I think it’s time to start building my magnetic loop – my next project.

The pack is very compact, it’s a good thing forcing the weight down. I have to make a plan with all those cables though!


I made a few contacts and always great to do some in CW too!


RaDAR – A reality check


This was the lightest configuration I have used for RaDAR to date.

RaDAR is about rapid deployment and in the case of moving stations, rapid movements too. The distances for various methods of transport are different to more or less equal the playing field.

Successful rapid deployments come from practicing RaDAR on a regular basis. Doing too many things at once can slow down the process too. Planning is also an effective means of increasing the rapidness of deployments. Not only is the physical deployment important but successful communications too. They go hand in hand.

Julian OH8STN demonstrated the effectiveness of digital radio (PSK63) during the recent RaDAR Challenge using Android Apps interfaced to a low power radio, the FT-817. Sid ZS5AYC demonstrated the effectiveness of using the mobile to move from point to point but also the possibility of a team effort in getting an effective station deployed quickly and ready to make contacts.

On foot RaDAR operations seem to be the most challenging. The fact that the operator needs to move quickly means he / she needs to be relatively fit. The gear needs to be compact and also easily deployable. Physical activity requires a well fed and well hydrated radio operator.

Experience has shown that a lot of time can be saved with ready to use systems within the backpack. Antennas should be easily deployable and the use of reels to roll up antenna wire is essential for speed. The antenna also needs to be effective and the losses in UNUN fed end feds, although they are quick to deploy, make them not good enough for decent communications.

The on foot operator needs to travel as light as possible and that is a challenge in itself. By no means should a water bottle be left behind.

Back to the drawing board for me.

73 de Eddie ZS6BNE

RaDAR – The clothes line antenna

During this year’s challenges I really would like to get another R2R contact or two again. Digital modes or CW may help.


I’m contemplating using my roll up “clothes line” dipole / inverted vee antenna. I did a few quick calculations for starting lengths for particular bands. I will make marks on the flex wire insulation for faster band changes.

Single side :

28.060 – 2.54m

24.906 – 2.86m

21.060 – 3.38m

18.070 – 3.94m

14.060 – 5.07m


7.030 – 10.14m

I’ll need two nylon tie ropes on each end.

RaDAR – Hamnet 24 hour field ops June 2014 day 2

Day 2

Day two started from midnight. I had been giving feedback on the ops on Facebook sending photos of what was happening at tactical comms point – Molopo.

I needed to charge the smartphone. I used my Waeco battery pack as a supply. It has a 18 A/Hr battery inside and was my backup 12 volt power supply. I had a netbook DC to DC converter with a 5 volt USB port on it. I used this to charge my smartphone. This was about the worst mistake I made throughout the ops, the charger drained my battery! Better to carry a spare cellphone battery or two.


Being a cold winter environment was a good excuse to store my 7 A/Hr SLAB’s in an old video camera bag. It was an all round good idea, easy to transport and I carried other items like rechargeable penlights and general power cabling in it too.


I exchanged messages with Hibiscus and Taqua on channel 2 (3.695 MHz LSB) just after midnight. The band had quietened down and not much activity could be heard. I called a few times without response.

I thought it a good idea to get some sleep. The gas lantern had been running all night keeping the tent a little warmer while providing light (I still needed to use a headlamp though). I was warned by Jack, VK4JRC via Facebook that these lamps are killers and give off carbon monoxide. I did have one of the tent’s vents slightly open but would be a risk to have the lamp running while asleep – I may never wake up again! I slept till 06:30


At 07:01 I was active again working Morateng, Spaarwater, Waterberg, Secunda and Nigel on channel 2.

It was time to make breakfast before going RaDAR. I had some bacon, three eggs, a pan and gas stove. It was fun making breakfast for myself out in the field on a fresh winters morning.


Just before leaving to do a RaDAR deployment in the dense bush, I worked Hibiscus again on channel 4 (7.095 MHz LSB) 08:47 almost the end of the second last session.

The last three hour session

I used my Klaus mast again and “shortened” end fed antenna. I could deploy the antenna amongst the branches of a tree without the dangers of the antenna getting stuck up there. The mast, once again, was “bungied” to an available tree branch.


This was almost a “stealth” deployment in the dense bush. I placed my kit on the autumn leave covered ground as far from the end fed feed point as the 3 meter length of coax would allow.


I worked a few more stations on various bands. Hibiscus, Monateng and Secunda on channel 4, Vaaitjie on channel 6 (14.300 USB), and Nigel and Honingklip on channel 5 (10.125 USB).


The last session was the most fun while practising RaDAR in the bush. I was absolutely thrilled with the multi band capability of the simple 9:1 UNUN fed “shortened” end fed antenna tuned with the LDG z817 automatic ATU. The FT817ND worked well and 7 A/Hr SLAB had  enough charge to last at least for another session or two.

I walked back to base camp, sat in the sun for a while, packed up and went home.

What an awesome ops!

RaDAR – Further feedback on yesterdays ops


After my rather challenging and most important contact with John, ZS5J resident in the UK I set up station for digital communications.

From past experiences, I was concerned about RF feedback but the 10m wire J-Pole did not cause such effects.

I don’t think I’ve ever done digital on 10m and only just recently discovered the default frequency being 28.120 MHz.The 10m band was crowded with PSK stations. My strategy was to work between 1000 Hz and 1500 Hz, even outside those ranges there was little space to call CQ. I had two possible QRZ’s but overrun by stations a few Hertz away.

I hadn’t really planned to use 15m or 20m but made up a 10 meter length of wire for the Fuchs just before leaving for the ops area. I usually use a length of 21 meters. I replaced the J-Pole with the 10 meters of wire and connected the Fuchs tuner. I could just not get the SWR down, 15m and 20m digital was loud and clear!


End feds have worked for me in the past and certainly have their place but the magnetic loops are looking all that more attractive. I have learnt a lot from friends in the RaDAR group.

I have just received a reply from John MW/ZS5J for a confirmation on his deployment methods – John has been with RaDAR since the early SiaS days! Did we achieve the ultimate goal? Yes, we did!

“Hi Eddie – I was only just able to hear you with all the European QRM we get here. I used my IC-703 with 5 watts and put up a 10 meter fibreglass pole with vertical dipole hanging off it. It was strapped to a fence post on top of a hill. Worked about a dozen USA QRP hams on 29.060, but you were the only South African I could hear.”



RaDAR – Strategising for the new contest


RaDAR has gone global. This calls for a whole new different strategy.

RaDAR has been refined and indeed will be refined even further once we share experiences. RaDAR must adapt to change – improving each year. What the goals were in the past are not necessarily the goals today.

The RaDAR operator has no idea of how many like minded people will be active for those four hours. There is no doubt that RaDAR looks attractive to the majority of radio hams but to really be active requires participation. RaDAR caters for everyone. It is not only operators in the field doing things the hard way, RaDAR operator need “big gun” stations operating from fixed locations or portable locations too!

So what is the ultimate goal this year, tomorrow afternoon to be exact? The greatest prize, intercontinental, RaDAR to RaDAR QSO’s! The mere fact that it earns the operators each 10 points will be nothing compared to the satisfaction of achieving this success!

I will spend the first hour, 14:00 to 15:00 UTC, doing an initial deployment by mountain bike (weather permitting) and looking for stations on 40m. I’m hoping that there will be a good turnout of South African operators. It’s the same with any other contest but I’m hoping that many operators take on the RaDAR challenge and discover not only triumph but the hardships too. It makes the success all that sweeter!

From 15:00 UTC till the end at 18:00 UTC I will concentrate my efforts on 10m CW, SSB and PSK31 around the RaDAR calling frequencies and 28.120 MHz for digital – 1000 to 1500 Hz. This will give the best chance running QRP to make DX contacts – hoping for the ultimate prize! Naturally, after every 5 QSOs, location needs to change so I’m going to try to move as fast as possible, deploying quickly at each new location. Taking grid readings using HamGPS for a 10 character locator.

I am in the fortunate position to have a decent fibreglass mast that goes up to ten meters donated te me by Klaus ZS1QO in support of RaDAR and my roll up 10m wire J-Pole antenna. Tests have proven this to be an extremely effective combination!

Good luck to all the RaDAR operators worldwide – may you achieve the ultimate success!

Those going into the twighlight zone – don’t forget the mosquito repellant and your headlamp!

73 de Eddie ZS6BNE