Monday, October 10, 2011

F3F Timing System: less wireless, but reliable and even more language versatile

After previous reported delusion of the 2.4GHz wireless base handles, I opted for walkie-talkie wireless signals from the bases. At first test, it seemed to work flawlessly and we even could start doing some runs! It's when we changed pilots at each bases after a while that quite obvious problems started to arise.
First of all problems was lacking segregation of signals between base A and B. B could involuntarily act as A, beeping an "on course" signal during altitude gain phase when the pilot chose to try a first climb past base B! Of course the system couldn't know the signal had to be discarded.
Second obvious problem arose when some paragliders on a hill some 3-4 km away, hearing so many "roger beeps" on their favorite channel 1, started calling us on the walkies. Of course, they only wanted to know if we were maybe in some trouble, or if we wanted to communicate with them. But at each call from them, the system recognized their roger beeps as base beeps. Even after switching on other channels, we had some "inadvertant" call at one point or another, invariably leading to a reflight...
So we tried again, this time using the sub-channel scrambling on the talkies. This would heve been perfect, except of the huge time lag between base button press and acknowledgment by the receiving talkie connected to the timing system. So whatever we tried, it was useless.
After so many mishaps in trial and error, I draw the only conclusion that was to be drawn: buy some 100m of wire!
Soon said, soon done. After some coordination with Martin Ulrich to use the same wiring and components as his F3F buzzer, my "little less wireless" timing system is now equiped with 2 x 53m wires to bases A and B. Each grip has two nice expensive splash protected buttons, one blue and one red. At the wire ends, there are nice XLR plugs for a secured plugging. And from the central derivation XLR box, there is 5m of wire to connect to the timing system, still enough for the CD to be able to move a little if needed. Now base buttons work fine and are finally as reliable as in every other F3F timing system. And since Martin's and my wires and handles are exactly identical, we'll have spare if we eventually suffer some accidental cut of one of our wires.
Since I didn't have to pull out my already sparse hair because of the bases, I could concentrate on some more improvements I intended to make. One of them was to add German language to the already English and French speaking system. This is now reality and I am glad to have countdowns or run times spoken out in those three languages based on the language code of each pilot in the pilot's list on the memory card. Next on the list are probably Italian and Spanish, but this will only be added during the winter.

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