As usual, Horizon extensively field-tested the 9303 2.4 for performance and reliability before sending units outbound to team members for further input. (Our internal R&D team perform extensive evaluation on proprietary products to ensure team members have a positive experience.) But we weren’t quite prepared for the response we got from Quique Somenzini, flying a pre-production prototype of the new blockbuster JR 9303 2.4 system. Here’s what he had to say:
“I just flight tested the X9303 2.4 DSM2 system with the JR R921 2.4 receiver and I am so impressed with the response and resolution that it seems like it’s a whole new era. The system is the most precise radio I have ever flown and I can “feel the difference” more than ever.
Yesterday I flew my Python 100 and Yak 73” with my favorite 10X to trim them up – they were flying very nicely. Last night I switched both planes to the 9303 2.4 and the difference was remarkable. I got 130 paces of ground range and when I took off for the first time it took me five seconds to learn I was flying the radio of the future. As I flew tougher and tougher maneuvers, the more I smiled and thought ‘what a radio.’
Here’s the way I look at it: the 9303 is a very successful radio – the programming is best in its class. On top of that, JR’s adding Spektrum’s 2.4 technology and it’s a combination that can’t be beat. When you add in the fact that there are no more worries about interference, pins or RF noise, it’s clear this is the radio of the future.”
We couldn’t have said it better ourselves. Look for this blockbuster radio to be in your retailer’s stores this summer.
UPDATE: Quique’s “unscheduled landing” during noon-time demo at SEFF underscores the importance of an adequate power supply when employing 8711 servos.
Quique flew his new Python biplane, equipped with the new JR9303 2.4 and seven 8711 servos, during the noon-time demo at the fantastic SEFF event last weekend. As usual, his dazzling display of high alpha rollers, on-the-deck high speed slow rolls and other superb maneuvers thrilled the crowd. However, after about 5 minutes of hard flying, he was doing a torque roll and lost control, sending the model into the grass with relatively minor damage.
A team of Horizon engineers retrieved the model and along with Quique, set about to find the cause. As we all know, often crashes are hard to explain, but after some investigation, we were able to determine the cause of the crash beyond a reasonable doubt.
By employing seven of the 8711 servos, the demands on the power system increased. As needed to produce the 403 ounce inches of torque, the 8711 will draw more current to do more work. Fact is, the 8711s sustained current can be 3.9 amps.
Quique’s voltage regulator was a 7.5-amp version, and probably survived his test flights in Ohio due to the lower ambient temperature. But at SEFF, with temps higher than he’d flown in, the operating temperature of the voltage regulator soared, causing voltage to the receiver to drop below the operating threshold of the receiver (3.5 volts), resulting in a system shutdown.
We know this for two reasons:
- In the hangar, we were able to apply light loads to the servos, and in short order we observed the voltage drop below minimum operating voltage. Even operation of all servos simultaneously (with no load) indicated a significant voltage drop.
- Upon retrieval of the model – before the power was shut down, we plugged in a Spektrum analyzer to review the number of fades and see if the system received any dropped frames. Normal flight will usually see a number of fades in the multiple receivers (this is normal, as the best signal is utilized between receivers with the Spektrum technology) but in Quique’s model, the counter showed “0” for all parameters. The only explanation would be that the receiver had been shut off in flight (data is not stored when the power is disconnected).
What’s the lesson? 8711 servos are powerful, and allow your model to perform as never before. But steps must be taken to assure the servos receive adequate power supply.
Furthermore, while regulators have their place in certain applications, we urge all fliers to review their use and use caution when old-generation regulators are combined with the new generation of high power servos. And to set the record straight: The buss bar power system in JR/Spektrum receivers is very robust, capable of withstanding continuous current far in excess of 20 amps.
Follow-up: Quique’s Top Gun Demo
The weekend following SEFF, Quique delivered a fantastic demonstration of his incredible Yak—equipped with the same 9303 2.4 radio flown at SEFF. Naturally, Quique made adjustments to the power system in his Yak, assuring adequate power to the radio system.