25-Jun-24 - 06:55 PM

Thermal Circle Text - Thermal Circle 14

Written by Hayden Daley - 03/12/2007.
Welcome to this edition of the soaring circle. In this edition we will take a close look at the Multiplex company's most advanced radio the Profi 4000 and at the end of the column I will be giving details on several new models now being distributed in Australia that I believe to be very good competition models. There is also some details on some affordable electric soaring models that are easily available in Australia.

Multiplex Profi 4000

The Multiplex Profi 4000 is a high quality tray radio manafactured in Germany. It has a number of unique features in its programming to set up F3B and F3J models, and the Profi 4000 is one of the few tray radios that allows for easy use of RC pilots that fly with thumbs. The radio has a very narrow case and this allows for long and short sticks to be used, covering all flying styles with comfort being a great asset when using this radio. There is also a Multiplex manufactured tray available for the Profi 4000. The radio has twelve proportional channels and also has a switchable backlit screen that makes for excellent visibility in poorly lit workshops.

I treat each new computer radio as a new computer "program" to learn. Whilst this radio is unique in its programming, once you have a basic understanding of the program pretty much any adjustment can be made on any channel or function. This radio also has plenty of mixers and these allow for complicated setups of all types of Scale, F3B and F3J models. This radio offers a 16 bit micro processor system which allows for software expansion and software updates as competition modeling evolves. The radio can also be hardware updated with stick switches and other hardware such as larger/smaller switches, more switches and other expansion parts. This radio offers different base types of programming, essentially computer programming which can be more or less complicated for the model required. The Universal mode provides all of the features the radio has to offer, essentially all functions are provided to be used. All basic programming you will find in every computer radio is in this unit, however with all switches controls and functions assignable and adjustable you can get really complicated models set up properly. This "assignability” is provided by very few radios and the Profi 4000 does this very well. The base of all programming in this unit is the use of progressive menus. These menu choices open up all the programming option's in this radio, once this feature is understood it allows more and less complicated programming to be achieved. There are five main menus and these have been designed to be used in order to program, essentitally menu 1, leads to menu 2 and so on during the set up of the model. The model sticks also intergrate with the programming, and in certain cases moving of the sticks is required to program.

The combi-switch function provides for easy coupling of aileron and rudder, the mix is assignable to any switch on the radio and this function makes models turn better, any mix will provide this but this setting on this radio allows for different rates; and when switching flight modes this setting can be adjusted. It very useful and this "specific" name in the programming makes this function easy to find when programming.

This radio has a built in scanner which actively scans the frequencys and prevents the radio from transmitting if someone is on your channel. It also scans the whole band for radios transmitting. The company name for this feature is "channel check" and it is patented technology. Also if there is interference on your channel the radio will also lock out. This radio uses a high capacity 3000 mah, NiMh pack as its power source. It provides for long usage times and lots of flying with the one charge. I am a big fan of large battery packs in transmitters and as these radios provide a full day of competition flying. The radio can also be easily opened to allow for direct charging of the battery pack. The radio also has a larger than usual aerial which must provide a better signal than smaller aerials and the aerial can also be swiveled taking the aerial out of your line of sight.

The Profi 4000 has memory for up to 99 models. It is very doubtful if all these memories would be required, but it does guarantee the owner that the radio won't run out of model memories. Model memories can be copied, allowing the "backup" of model programs when changing setting's, you can keep a copy of the original program, and if an error is made you can change back to the original program.

This radio has built in stopwatches and timers, these are highly useful for competition soaring with alarms providing an audible warning as the time is reached. These timers can count both forwards and backwards allowing you freedom to time flights whilst practicing by simply flicking a switch to activate these built in timer's. Another highly useful feature for F3B practice for the distance task is the lap counter which counts laps flown, by using a switch to activate the function. I do not know of any other radio with this function.

The Profi 4000 has different transmission modes. This covers all Multiplex receiver options and allows for the use of other FM receivers from other companies. The modes are PPM7, PPM9, PPM12 and the Multiplex receivers PCM/A mode. Please note when using PPM receivers from other companies with Profi 4000, that an FM transmit adjustment needs to be changed to match receivers that are not Multiplex, this radio transmits in a different format than other companies and to use other companies receivers reliably this adjustment must be made to the FM transmission mode..

I have mentioned the flight mode function previously and this function allows for up to five different model settings to be switched during flight essentially different "phases" of flight, have different settings. Once the flight modes are assigned you can name these modes so that when the mode is changed the mode in operation is displayed on the screen. For competition soaring this is really the only way to get the required settings for launch and for F3B models the settings for the distance, thermal and speed tasks to be activated during flight. Flight modes are probably the best feature on this radio, it allows for complicated models to be set-up properly for all phases of flight.

When programming F3B models please note that three model memories will be required, a seperate program for speed, distance and thermal. Also if setting a up an F3B model for F3J, another model memory will be required for the hand-tow launch setting. Typical names for flight modes for the F3B distance task would be launch1, launch2, reflex1, distance1 and landing1. The co-pilot unit is available as an option and provides speech to the Profi 4000. This feature can "say" when flight modes are changed, when timer 1 and timer 2 are activated and the Lap number and lap time when counting laps. These speech announcements can be changed to a time setting, where the speech is activated every thirty seconds for example.

I have no experience with Multiplex radios, and spent 45 minutes using the radio. The Profi 4000 has 6 butttons and a rotary knob to allow for swift changing of the settings. In this time I managed access most settings required to set up a competition sailplane. I changed some simple settings and moved the sticks to allow for changes in throws. I accessed the flight mode settings in the menus and got a reasonable understanding of the programming required to get this function working. I used the servo reversing function and found other useful features in this time. Overall a very versatile unit and I believe within 4-6 hours most people would have an understanding of the program and would not require the manual for most model programs. With a total grasp of the radio programming I believe that a 12 channel model could be set-up completely in 20 to 30 minutes with all functions and flight modes working.

The Profi 4000 is a well designed 12 channel radio. It has features for all types of competition flying and it can be expanded to suit all styles of model flying. This transmitter provides unique features for competition soaring. The narrow width of the radio allows for use by all model pilots whether they fly with a tray or with thumbs. The Multiplex line can be purchased from all hobby stores that deal with Model Engines and I would like to thank Model Engines for providing the Profi 4000 for review.

New Competition Models

The Airstrike Company are now bringing into Australia the Jaro Muller Espada, the Europhia 2 and the Shadow as new models in there line up of competition models. Personally I am a big fan of purchasing molded models from Australian distributors because it effectively ceases any importation dramas and for a small increase in cost can save problems with customs, delivery times, etc. I have been to several competitions recently and the following models showed exceptional performance.

The Espada RX was definitely the best performing Jaro Muller model with wingspan of 3.242 meters, the wingsection was the HN-785JM a Norbert Hayes wingsection and a wing area of 62.7 dm2. The Espada has a dry weight without ballast of 2050g. This model is exceptionally strong and stiff, a Victorian competitor launched this model higher than I had ever seen previously in winds of around 15 knots.

Another model that performed well was the Europhia 2. This model was designed by Martin Weberschock a long time innovator in F3B model design and I believe this model would make an exceptional heavy weather thermal model. The model has span of 3.188 meters, the wing section starts at the root with Estrella section the MW3 and transition's to the new MW4 section. The wing area is 52.4 dm2, and the models dry weight without ballast is 2400g..

The Shadow provided exceptional performance in a well priced model suitable for F3J and as a light weather thermal model for general thermal competition. It has a wingspan 3.654 meters the wing section used HN507m1 from Norbert Hayes and has wing are 73 dm2. The model tracked well and with a weight around 2kg is light for its size.

Electric Soaring

The ability to climb to launch height without with out having to collect bungee and winch lines has to be the greatest advantage of electric powered soaring models. And with an electric model in your vehicle for light weather slope soaring, gives you the ability to test the lift at a slope sight before launching a model without electric power. The price of Li Poly batteries are expensive, however if you are prepared to go with older technology and use 7-10 cell Nimh or Nicad battery packs you can dramatically lower the price of setting up an electric model. When not using LiPo’s battery chargers become cheaper and the main advantage of using older style, Sub C size, NiMh and Nicad batteries is faster charge times. The price of Sub C battery is around five dollars and the following models are suitable for this style of power. They would perform better and be lighter with LiPoly’s but they are not required. The price of brushless motors has dropped dramatically, but all of these ARF models could also be easily powered by brushed motors and still perform well.

Thunder Tiger E Hawk

The E hawk comes recommended as a suitable model that wont break the bank to set up with electric propolsion. It has a wingspan of 55 inches and a wing loading of 10oz/sq ft. A 380 electric brushed motor is included with the kit and the model requires a 3 channel radio. The fuselage is of fiberglass construction and has well constructed partially sheeted wing. I have flown this model it is not bad. Overall an excellent value model designed for electric soaring

FVK Electron

The Elektron from the reknowned manafacturer FVK models has been devoloped for soaring flight. It features a strong but light weight construction and the wing is covered in Oracover. The fuselage is of GRP construction, and the ailerons are cut and hinged. The wing servo boxes and wiring are already installed. The model fuselage is available in cruciform tail, v-tail or tee tail. The models weight allows for affordable electric equipment and comes highly recommended, this manafacturer is reknowned world wide for quality models and is available from Model Flight

Multiplex Easy Glider

The Easy Glider electric is a well priced model from the German company Multiplex, it is distributed to hobby stores by Model Engines. It offers fast construction with CA and it is capable of handling the occasional heavy landing. The model uses rudder, elevator and aileron control and would be suitable as a first aileron model. The two piece wing provides easy transport. The wingspan of this model is 71in the fuselage has a length of 44.25 in and weight is 35oz.This model comes with a power system including motor. I have seen this model fly many times and it has excellent flying characteristics and performs well

Graupner Cumulus 2000

The Graupner Cumulus design incorporates a removable nose that can be quickly changed to turn this model into an unpowered sailplane. This removable nose allows quick changes of batteries at the field/slope. The models wingspan is 1870 mm, it length is 965 mm and it weight is approx 900g complete. It requires 3 channel radio and an electric geared 480 motor with a 4.1 gearbox. This model is ready built, has a V-Tail and the nose cone for glider conversion is made of fiberglass. This model is well suited to affordable electric proplusion and can be purchased from Model Flight.

Available from:

Available from

That’s it for this issue, Happy, Safe and Succesfful soaring. I can be contacted at soaring@nerwlitho.com.au. Hayden Daley.

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Text-based competition soaring information website established 2007