RaDAR – Now a stable environment

Close on a decade later, RaDAR has become what it is, a little different to anything else but a compliment to any amateur radio activity. The slight changes made to last years rule base is the final thumbprint of RaDAR. Here are screen snapshots from the “Blue book” regarding the RaDAR challenge held three times a year, internationally. The support base can only grow from here …..

Have fun!

73’s de Eddie ZS6BNE

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RaDAR – Automating field SatComms

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I’ve always promoted SatComms for use in RaDAR. It certainly has its place there.

Recently there has been renewed interest in the satellites in South Africa and we are starting to use the relatively new cubesats and the CAMSATS. The CAMSATS prompted this article as I have some new questions that need answers. The CAMSATS are amazing satellites and they fly in “Formation” requiring a lot of attention from the satellite user switching in the appropriate frequencies as each flies from horizon to horizon in quick succession!

Working “half duplex” is fine when there are two people on the satellite at one time but when there are three or more it becomes quite challenging with great risk of interfering with possible other QSO’s taking place within the pass band of the transponders.

It’s still good practice to do things by hand and should be practiced but once mastered it’s more convenient to utilize a little computer assistance. I used to use SatPC32 which worked well with the 847 I used to have. CAT control of dual VFO rigs for satellites works but it has its problems! While the VFO’s are updated and you press the PTT at the wrong time it’s possible that you may transmit using the wrong VFO, especially with the 817. The 897 seems to be a little more “tolerant”. If you are monitoring the downlink on another radio it’s possible then that you transmit on the downlink frequency blasting your headphoned ears with strong audio! This is the problem I have and I need to devise a means of working RaDAR SatComms in the best possible way. It also needs to be done to protect the receiver radio!

The proposal.

Just this weekend I rebuilt my HP 210 NetBook computer to control the FT-897d via CAT only to initially set up the uplink and downlink frequencies on the dual VFO’s (Working SPLit). The receive VFO frequency will then indicate what frequency the FT-817nd should be set for the downlink. From there on it’s manual tuning of the higher frequency being it the uplink (u/v) or downlink (v/u) working full duplex and able to listen to your own signal through the transponder and of course others. The process of “Netting” is used to get onto another stations frequency.

Note, each radio has a direct coax connection to the 2m or 70cm yagi of the Arrow antenna. I use the more flexible (but lossy) RG58cu coax but it works acceptably well.

There is still quite a measure of manual control but better than working “blind” and of course keeps the RaDAR operator sharp and focused without the need to look up written or printed frequencies on paper (usually in the dark). Of course this relies on the computer.

I have found too, that tracking the satellite by hand is easier while standing so the rigs should be arranged such that they are easily accessible even while standing.

I use the 817’s shoulder strap and hang it over my Arrow’s tripod but still need to find a way to do something similar with the FT-897d. I power both radios off a 7 A/Hr SLAB that usually sits on the ground.

RaDAR – Flag wars

My grandson (11) and I (58) developed this awesome game this weekend. Lots of fun and good RaDAR physical training too! Next to our little house “down by the burning river” we have a four hectare area with rocks and many bushes.

Flag Wars

by

Eddie and Eduan Leighton

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Requirements:

Own water and backpack.

Protective headgear or cap.

Sun protection.

Trail shoes.

A general recce to be done by all competitors before the games begin.

Experience needed:

Danger awareness.

Trail running.

General fitness.

Possible dangers:

Twisting an ankle

Flesh wounds caused by thorn bushes / trees.

Unseen holes

Tripping over rocks

Snake bites but the chances are very minimal (it needs to be mentioned).

Rules:

Each competitor places his flag pole on his side of the “operational area”.

A call is made to start the game.

Each competitor moves out to find the other’s flag trying not to be seen.

On finding the opponent’s flag, move back to your flag (Hopefully knowing where it is!).

Once back home with the opponents flag, you have immunity and thus win the game.

If you are caught by the opponent while carrying the opponent’s flag you are taken prisoner and the opponent wins the game.

Experiencing the game:

My route back to “camp” running back with Eduan’s flag. He saw me and gave chase, pretty fast kid I know, and he was close on my heels! I jumped the rocks entering the “desert area”, swung left and bolted for my flag hidden among the bushes, seconds from being “caught” and held “prisoner” and losing the game.

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In desperation to get away from him I ran through thorn bushes, the same just touching his forehead. Next time he must wear a cap, at least.

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Eduan won the first round, he sneaked back with my flag before I even found his!  He can also track you, quietly without being seen! He’s a natural!

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He said, it’s the best game he’d ever played against his granddad!!!

RaDAR – Pack dilemmas

The RaDAR challenges for 2016 are done and dusted, that besides occasional fun deployments, each time learning new things and discovering new ideas.

A while ago I made cutouts between my mid sized pack’s compartments to route cables or whatever was appropriate. This weekend my XYL Elrika, added some finishing touches in the form of curtain rings. It’s the answer!!!

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My minimalistic pack had surpringly good results but it is what it is, minimalistic and not intended for a lengthy amount of operating time and also QRP is the highlight even preferably less than 5W.

My favourite pack was always this mid sized pack but I have thought about storing some of the goodies in different places. At the base, as always, the car wash sponge for shock absorbtion for the rig etc. or possibly place for a 7 A/Hr SLAB stored in a plastic container. Then a 5 litre plastic container with it’s top removed to hold the Rossi / flashlight / battery, 817’s mic, morse key (Straight or a paddle), compass, dedicated smartphone for digimodes then the Yaesu FT-817ND and LDG z817 ATU.

A “shelter” and logbook accompany the latter. Then there is the Garmin Legend backup GPS with built in maps. It can also be used for APRS if the need arises.

Antenna hardware in the side pockets be it an end fed or link dipole and coax leads. A tool kit in the back compartment, also a place to carry food, water and a windbreaker.

If doing RaDAR Satcomms (Something that has become the highlight in South Africa the past two weeks) there should be a special place for my 4 x AA cell powered Kenwood TH-D7A handheld, a full duplex solution for amateur radio satellites like SO-50. An Arrow antenna can be carried in one hand, reasonably lightweight and easy to handle if carried in the centre.

Time to pack and test the new configuration! Somehow having the radio powered within the pack allows faster deployment times. Maybe time to return to that school of thought ….

73 de Eddie ZS6BNE

RaDAR – The last challenge for 2016

I chose my four hours of twenty four to coincide with returning from a nearby town where we took young Eduan to meet an old primary school friend for his birthday. After a hearty breakfast, they watched a kiddies movie together while Elrika and I did some window shopping at the mall.

We got to the RaDAR playground (just) in time and my first deployment was for SatComms on SO-50. Many of us in South Africa have the experience but are rusty. Using my TH-D7A(g) (Running on four AA alkaline cells) and Arrow antenna, I was able to have a QSO with Rickus ZS4A before the bird went over the horizon. I even forgot to tune for doppler!!! I was lucky …..

That earned me my first RaDAR contact and five bonus points for the first satellite QSO, counting my movement to the first position as travelling by car even though the travelling distance from the mall was close on 150 km, a little more than the requirement 🙂

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The app I use for satellite pass predictions is “ISS Detector” for Android. It works very well for the purpose of RaDAR and always accurate. A reliable tool!

2016-1

I had my minimalistic RaDAR kit packed and ready. It includes the FT-817nd with eight AA internal batteries, straight key, mic and 40m end fed with coupler. I moved out, on foot to the next deployment point.

I use the Android app “Ham GPS” to determine my grid square to 10 character accuracy. Also a great tool for RaDAR!!! An ideal website for displaying these grids can be seen here.

2016-2

It was quick to get the end fed deployed using a tree branch and nylon rope to raise the middle section of the end fed as high as possible, in this case around four meters above the ground. Perfect NVIS configuration for 40m.

2016-3

As with all my field antennas, I build in a bungi shock system to protect the antenna from the wind or tripping over the wire. I quickly got the rig deployed and started to look for contacts.

2016-4

I managed to work ZS5HAC, ZS3VDK and ZS4A all on 7.090 SSB. Signals were reasonable especially ZS3VDK who was very strong. I took a video which I will later edit for You Tube upload. There was no CW activity on the band …..

It was time to get back home where I’d left the satellite equipment. SO-50 had just gone around the world and coming over the horizon again. I quickly packed up and walked / jogged back home.

This time round it would be classified as fixed station RaDAR. I got everything ready and made contact with Andre ZS2BK and I remembered to tune for doppler! Unfortunately no other signals could be heard on that pass.

The next part of the plan was to take the QRO kit for a walk ……. it started to rain.

I deployed on the patio, the FT-897d and battery supply. I lifted the link dipole into the tree in the garden and set the links for 20m. All I could hear was an obliterating noise, 59+ which made communications impossible. I tried switching off the power to the house but the noise stayed. It was coming from somewhere else.

I called it a day ……

Lessons learnt. Certainly the minimalistic RaDAR setup excelled in it’s purpose. Very light weight and easy to move quickly. An effective communications method. Satellite communications were reliable within the footprint of SO-50. I even managed to activate the transponder myself as it came into view (74.4 Hz CTCSS).

Till next year!

73 de Eddie ZS6BNE

 

RaDAR – The awesome end fed

In my minimalistic RaDAR kit, I carry a 40m half wave end fed antenna and manual tuner / coupler / impedance matcher – it’s actually all that, as simple as that. A parallel tuned circuit made of a few turns of enamelled wire wound around a tiny red coloured TO50-2 toroid and a varicap. Lightweight and the size of a matchbox, and it’s a matchbox!

I found some images I’d saved from the Internet a while back which are really excellent in showing the versatility of the end fed!

Many thanks to KC8AON for the these images!

 

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Hope to hear you on the air some day …… 73 de Eddie ZS6BNE

 

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