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1

Electrics / New GPS-V Powerbox: how it's made

« on: April 11, 2026, 14:04:17 PM »

Hello everyone, I’m back again to review an accessory that I think is particularly useful for those who use a gyroscope on their aeroplane or for anyone who simply wants to monitor flight data via telemetry. Today I’ll be talking about the new “PowerBox GPS-V” satellite device, which represents the latest evolution – updated in both software and construction – of one of the most popular accessories among model aircraft enthusiasts. I have personally tested this sensor on my 3-metre Fox FMS glider, fitted with a 10-channel Jeti REX Assist receiver. I will divide my review into sections covering the various specifications.

Hardware and Technology: what’s inside the GPS-V

The sensor, like previous versions, is extremely compact (60 x 18 x 15 mm) and lightweight (14g) and uses industrial-grade components that guarantee superior performance compared to standard consumer products. The main features are, in order:

• Helix (radial) antenna: Unlike older flat antennas, this design ensures reception even when the model is in extreme flight attitudes (barrel rolls, spins, inverted flight).

• U-blox MAX10 chip: Enables a fast satellite ‘fix’, proving effective even in partially obstructed conditions. My outdoor test recorded a time of between 25 and 30 seconds to lock onto satellites and become operational.

• Doppler speed: in the GPS-V sensor, speed is not calculated using the distance between two points (the classic but slow method), but by exploiting the Doppler effect on satellite signals, eliminating any delay (lag). The Doppler effect on satellite signals is the apparent change in the frequency of a radio signal (electromagnetic wave) emitted by a moving satellite relative to a ground-based receiver (or vice versa).

• MEMS (Micro-Electro-Mechanical Systems) Barometric Sensor: This is a very high-resolution hybrid system that combines GPS data for absolute altitude and the barometer for relative altitude, with an accuracy of approximately 10 cm. Its operation can be summarised as measuring atmospheric pressure and converting mechanical deformations into electrical signals; the sensor contains a sealed vacuum chamber beneath a silicon membrane.

• Compatibility and Protocols (see table)

The device is Plug-and-Play (accepts voltages from 4 to 9 volts) and automatically recognises the radio protocol (Core, Jeti, Futaba, Graupner, etc.) as soon as it is connected. However, this Powerbox GPS-V, at least in my Jeti 10 Assist receiver to which I paired it, required connection via the E1 (Exbus) port, whereas it was not detected by the receiver when connected to the traditional Ext port (the input designated for the Serial bus/sensor). In the table shown in the photo, I have included some technical notes on compatibility.

Practical Tips for Installation and Flight

To get the most out of the GPS-V, it is advisable to follow some precautions outlined by Powerbox but which also stem from practical experience: 1) Positioning: If possible, keep the sensor at least 5–10 cm away from the Assist receiver to avoid electromagnetic interference or resonance. 2) Shielding: avoid covering the antenna with carbon fibre materials and always point it towards the sky. 3) Barometric pressure: do not expose the sensor to direct airflow (propellers, fans or fuselage air intakes) as this would cause false changes in altitude. 4) Stall management: remember that the GPS measures ground speed; with a strong tailwind, the aircraft could stall even if the indicated speed appears high. 5) Jeti safety: In my case, as I have all Jeti receivers and DS16s, care must be taken, in the event of a loss of GPS signal, regarding the possibility that the telemetry might read ‘0 km/h’, causing the gyro mixer to go to maximum. It is essential to set a fail-safe value (e.g. 30–40%) to maintain stable flight.

Conclusions

The Powerbox GPS-V sensor currently has few competitors on the market (you can count them on the fingers of one hand): there are similar devices, but they do not include all the features of this Powerbox in a single unit. Some offer the option of adding external barometric sensors but use older-generation GPS. In short, I believe that today this GPS-V could become the benchmark for those flying jets, scale models, aerobatic models or gliders. It is a robust, well-shielded unit designed to last for years even in harsh environments (turbine heat, combustion engine vibrations). Personally, I still have the first Powerbox GPS sensor in one of my models, and after all these years it’s still doing its job. Finally, I’d like to point out that the firmware can be updated via the ‘Powerbox Terminal’ app and the dedicated USB interface, as is already the case for all PBX devices.

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Jets / Re: Nostalgic for the Falcon 120? Is "Serpent" for those who love to build!

« on: January 22, 2026, 08:45:18 AM »

Two final thoughts to conclude this review. I found this kit particularly interesting in terms of the precision of the CNC cuts and the perfect fit of the joints; the kit is absolutely complete and requires no additional purchases, except for accessories such as hinges, connectors, components, etc. I have never seen such a complete kit. On the other hand, I cannot help but point out once again how, nowadays, it is possible to sell a jet kit without a single drawing and without even dividing (at least this much!) the parts that correspond to the same section of the model. It is really hard work to track everything down. And it is better to check three times before gluing!
The last question that naturally arises in a hobby sector such as model aircraft, where manufacturers compete to sell increasingly “ready to fly” models, is the following: is it worth going crazy to make something you can buy ready-made (and at little extra cost...)? My answer is yes, it's worth it if you are a model maker who loves to build, who has learned the art of model making from parents or grandparents who, 40 years ago, laboriously cut balsa wood and plywood by hand to make all the parts of the aircraft, which they then covered with paper and homemade paper stretchers made with trichloroethylene and polystyrene (...!).
So if you have this passion and want to spend this winter in the workshop building and are looking for a generously sized jet trainer, I think this model could be right for you. I repeat, you need patience because you have to proceed in small steps and without rushing. Use a good vinyl or aliphatic glue and give it time to harden well, savoring your progress little by little. You could also use cyanoacrylate to speed things up, but I don't recommend it (except for some non-structural parts) because it makes the joints rigid. But that's also the beauty of this hobby: you can achieve excellent results with different solutions.

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Jets / Re: Nostalgic for the Falcon 120? Is "Serpent" for those who love to build!

« on: January 16, 2026, 10:44:11 AM »

The rest of the assembly and finishing poses no problems (even the canopy, also made of fibreglass and epoxy resin, fits well to the fuselage, and the finish of the kit is a matter of personal taste. However, the simplest solution remains heat-shrink covering, which is quick and durable. It depends on your taste. The Serpent kit offers ample opportunities for customisation in both construction and electronics setup, but I must say that once assembled, it is a beautiful jet. Its flight characteristics should be good, thanks to a moderate wing loading, generous surface area and a good wing profile. The price of the kit is in the mid-range, but it is penalised somewhat by the fact that, at least in Italy, customs duties are applied to shipping, although these vary from country to country.
Now let's take a quick look at the electronics and motorization section. As mentioned at the beginning, this jet will be powered by a Kingtech K65 turbine, which is lightweight and provides sufficient (but not excessive) thrust to get the model airborne. Those who fly on grass runways may be penalized by the fact that, with a motor at its limit, they will need more takeoff space, but in flight they will still have sufficient thrust. I don't have an 80N at home, so I will install the K65.
Given the particular nature of the space available for the electronic and power supply components, I had the idea of printing a custom-made tank at home with my 3D printer that could be adapted to the space, with a capacity of about 2 liters, to which I coupled a 250cc Uat. While I was at it, I also printed the covers for the wing landing gear compartments so as not to leave any open spaces under the wings where the landing gear retracts.
For electronics, I have relied on Powerbox for many years now, and in recent years I have appreciated the particularly small and lightweight “Pioneer” control units, with dual power supply and dual Rx and complete telemetry for the voltage of the paired batteries. It has only one limitation, which is that it cannot regulate the output voltage for the servos because this control unit returns the same output voltage as the input voltage. It is obviously a more economical control unit, designed for those who do not need too many functions but simply want a reliable, easy-to-configure, lightweight, and small device.

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Jets / Re: Nostalgic for the Falcon 120? Is "Serpent" for those who love to build!

« on: January 06, 2026, 15:11:06 PM »

This flu is causing me a lot of problems, but we're slowly moving forward.

This kit has been designed and manufactured with the aim of ensuring ease of transport and speed of assembly in the field. The solution adopted by Nicol Iad was to create a central part of the wing that houses the landing gear and remains attached to the fuselage. At the ends of this part are the two spars, to which the two vertical rudders are glued, which support the horizontal stabiliser at the top. The fuselage, the central part of the wing and the rear part with the vertical and horizontal rudders remain permanently assembled; in the field, however, the two wing halves must be assembled, which are attached to the central section with carbon bayonets and reference pins. This allows the entire model to be transported in a car with reduced bulk and easily assembled in the field. However, in my opinion, attaching the two wing halves remains awkward, as it is done using a through bolt on each wing half, supported in the wing structure by a block of plywood locked into the spars and ribs at that point. To attach the wing halves, everything is assembled, the bayonet and bayonet holder are drilled at the same time, and the through bolt or screw is inserted. No problem, except that it is clear that once the bayonet has been removed and the wing taken off, the next time we assemble the wing halves, we will have to match the two holes by rotating the bayonet, which is not easy. Everyone here can find the solution they prefer.

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Jets / Re: Nostalgic for the Falcon 120? Is "Serpent" for those who love to build!

« on: January 02, 2026, 15:11:47 PM »

The first thing to do is to divide the parts of the kit according to the various sections of the aircraft: tail, wings, central section, moving parts, fuselage and steering supports. And this is where the first problem arises: the laser-cut sheets are not divided into sections, but may contain parts for the wing, servo supports or spars with ribs of moving parts, as is the case with some sheets. This would not be a problem if all the parts were labelled with the name of the part they are going to build, but this is not the case. Others are printed with sequential numbers to be followed when assembling the wing or elevator, etc. Unfortunately, this kit does not even contain a drawing of the model with the various parts to be assembled, and I pointed this problem out to the manufacturer, Iad, but I received no response other than the advice to look at the photos on the Facebook group (https://www.facebook.com/groups/1350973201704574/). There are indeed many photos, but they are not enough to overcome some minor obstacles that may be encountered when assembling certain parts. A diagram is definitely essential for this kit, or at least it would be advisable to mark all the cut pieces with specific codes.
However, with a little care and by browsing through the hundreds of photos available, you can overcome any difficulties. Those who have already built similar kits will have an advantage, while novices will have to work harder. For assembling the various parts of the kit, I generally used Pattex vinyl glue and aliphatic glue, while for structural gluing I used two-component epoxy glue.
The fuselage of the kit is a single piece moulded in epoxy resin and fibreglass, and feels a little light to the touch. Before assembling the model, I reinforced the attachment points of the landing gear and wing with 160 g/m² carbon fabric to give it greater strength. The internal stringers and the front landing gear tower fit perfectly, while the hole in the fuselage for the landing gear to exit must be cut by the model maker; a plywood template is provided for this purpose, as for the wing landing gear bays. The front of the fuselage has a removable cone that allows access to a solid plywood base locked in place with the last fuselage frame, which will be used to house the batteries. All very functional. The central part of the wing is locked into the fuselage by means of a front joint on a frame and two nylon screws that lock onto a support glued into the fuselage.

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Jets / Re: Nostalgic for the Falcon 120? Is "Serpent" for those who love to build!

« on: December 30, 2025, 17:51:47 PM »

The assembly of this kit is aimed at model makers who have a minimum of experience in building pre-cut wooden kits, but I must say that, being only on my third experience, I realised that this kit is particularly accurate in the precision of the joints and the cutting of the pieces. To assemble everything, you need a few tools such as a sander, a mini drill, etc., as well as spirit levels and 90° squares for checking. In my workshop, I have a wide range of Proxxon accessories that I use for my work, and I must say that they have never caused me any problems. The great thing about these tools is that they come with a huge range of accessories of all kinds, perfect for building wooden/balsa wood kits. I have tried alternatives, but then I went back to buying Proxxon. This may sound like an advertisement, but since I now have a lot of tools at home, I can only emphasise their quality. Then again, everyone has their own preferences...

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Jets / Re: Nostalgic for the Falcon 120? Is "Serpent" for those who love to build!

« on: December 28, 2025, 08:37:11 AM »

Well, I couldn't resist and ordered a kit, which was delivered to me after about ten days. The packaging is excellent and protects the contents well, despite being a medium-sized box. Opening the package and checking the wooden sheets, I immediately noticed the quality of the cut and the ease with which the various components come apart. I was surprised by the presence of all the necessary pieces already cut, including the balsa boards for the rudder covers, the moving parts, the servo compartments, etc. Iad also supplies the canopy, also moulded in epoxy. For those who want it, Iad also has complete landing gear and servo controls in its catalogue. In short, it is a decent kit that sells for £540, equivalent to about €620. It is a pity that this kit does not come with drawings or assembly instructions. This is not the first time I have built balsa kits, but I must admit that it was tiring having to spend a lot of time checking a series of images on the group dedicated to this jet. Furthermore, the photos are roughly grouped by assembly sections and in “random” order, but you need to pay attention and look carefully before gluing. I pointed this out to Nicol, but he couldn't give me an explanation. In my opinion, it wouldn't have been difficult to provide a printout of the drawing, even if not to scale, to avoid so many inconveniences. In any case, I recommend (but those who are already experts know this) assembling the various sections first and only gluing them when you are sure they are correct.
(To be continued)

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Jets / Nostalgic for the Falcon 120? Is "Serpent" for those who love to build!

« on: December 28, 2025, 08:35:35 AM »

Do you remember the legendary Falcon 120, the jet that started out as a propulsion engine and was later adapted to a turbine? It was an economical model (the first kits cost around £200) and flew reasonably well. It wasn't beautiful and didn't have many frills, but it was affordable for many beginners in the world of turbines. It's a shame that it's no longer on the market (I searched the entire web for days), except for a few rare boxes from private sellers asking exorbitant prices.
Well, while surfing the net, I came across a British website offering a kit similar to the Falcon 120, but with a wingspan of 195 cm and a length of 192 cm (excellent!). It is called “Serpent” and is made by Iad Model Design (https://www.iadmodeldesigns.co.uk/serpent.php) , owned by Iain Nicol, a very helpful person.
It is a well-made CNC/laser-cut wood/balsa kit, derived from a design from a few years ago, but completely revised and updated. The recommended motorisation ranges from a 45N to an 85N turbine, for an estimated model weight of between 5 and 6 kg. The kit (unusually) includes all the wood needed for assembly, including spars, strips, leading and trailing edges, balsa sheets for covering, reinforcements, etc. For the fuselage, the kit provides a single vacuum-formed laminated piece (very light), for which all the reinforcement frames, bases, landing gear supports, bayonet holder and carbon bayonet are provided, ready and cut to size for gluing. Retractable landing gear is not provided, but is available as an option with wheels and brakes; I installed a set from JP Hobby complete with legs and wheels with brakes.

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Electrics / Re: Skywing Edge 540 91': electric is better!

« on: September 03, 2024, 17:36:42 PM »

August is over and we are back from vacation. I had interrupted my review talking about the firmware upgrade of the ZTW Esc to optimize it at its best with the Dualsky DA6000 engine. And from here I resume talking today about the choice of batteries that are the "fuel" of the electric engine. Today I want to focus on another fundamental aspect for the setup of a maxi model converted with an electric engine: the batteries. The choice of power supply can be subjective with regard to how many cells to use, their amperage or the brand but there is one thing that cannot be compromised, that is the quality of the battery chemistry. Unfortunately I also fell into youthful (and inexperienced) mistakes with the first electric models (both propeller and fan) but all this helped me understand that saving on this aspect is not always a good choice. Obviously the truth is always in the middle because if it is true that batteries of brands that have long been known and appreciated by even professional modelers sometimes the cost does not justify the advantages; as it is also true that low-cost batteries are often poor in terms of performance (especially if subjected to stress such as in electric fans).
And since I like to experiment (I have tried so many batteries) I took advantage of the purchase of the Dualsky GA6000 motor to also try the LiPo Dualsky G7 HED series, where HED stands for High Energy Density. The 6S 5800Mah packs measure 158x45x51mm for a weight of 774 grams.
These cells, according to the data provided by Dualsky, thanks to continuous updates (they are now in their 7th generation) manage to be not only high-performance but also lighter and more powerful (in fact they weigh about 50 grams less than other similar packs). They have a continuous discharge capacity of 45C with high dynamic performance that guarantees over 300 charge/discharge cycles without evident loss of capacity. Interesting that Dualsky worked with Xpower to be able to obtain the advantage of having an optimized discharge voltage in the low capacity phase which translates into Greater Power even with reduced capacity residues; it is in fact known that often in LiPos there are drops in Power with the decrease in battery amperages.
The Dualsky G7 HED LiPos arrive with the pre-soldered XT60 blue plug, but this could be irrelevant for those who use other types of plugs. Finally, in terms of quality, Dualsky batteries are scrupulously inspected before shipping to the Shanghai factory.
However, given the not excessive absorption of the motor which with the 24x10 propeller should require 100% Power of about 100 amps, these batteries should not be stressed. But I would not go below 5500 mha of capacity for any battery you decide to use.

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Electrics / Re: Skywing Edge 540 91': electric is better!

« on: August 18, 2024, 11:33:10 AM »

Good morning,
today I have some great news that comes to me directly from ZTW, the company from which I purchased the voltage regulator for this test, the ZTW Mantis HV G2 160A Opto that I talked about a few posts earlier. Reading the data of an ideal setting that Dualsky proposes for this motor (GA6000) with a 24x10 propeller (the sdame that I will use) I realized that although the ZTW Esc has the ability to modify some parameters, the accessible ones were not all those that I had to check for the optimization of the regulator and therefore I contacted the ZTW company directly to understand how to do it. To my great surprise I found exceptional availability so much so that the ZTW engineers purchased my same motor to couple it with the regulator that I purchased to maximize performance. Result? They sent me an update of the ZTW Mantis HV G2 160A Opto regulator that contains a specific setting for my motor (and consequently for other similar multi-pole motors) that will allow for maximum performance and reliability of the Dualsky/ZTW combination. I also received the ok to make this update available to all my readers. Fantastic, take advantage of it!
These is link for download file.

https://www.dropbox.com/scl/fi/huuawr71be53l36zbwxgs/Mantis-aggiornamento-GA6000.zip?rlkey=m4jkvflo7czfxw4cn6r84ul26&st=cm350iyw&dl=0

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Electrics / Re: Skywing Edge 540 91': electric is better!

« on: August 05, 2024, 16:34:52 PM »

Good evening guys. Forgive me for the long break but I had some problems that prevented me from continuing with the test. I take this opportunity to continue while waiting for the holidays that will inevitably lead me to a further break. But you will see that we will get to the end.
In the meantime, let's conclude with the topic of servo controls that we interrupted some time ago. It seems to me that I have already explained a lot to you but there are a couple of things that I still have to tell you. The first concerns programming: I have already explained to you that the graphical interface of the Yantrs software is truly complete and many parameters can be changed but this, in addition to being a good thing, can also be a problem for those who do not have the necessary skills to understand what is being changed with the software. My advice is that once a new servo is connected, it is best to save the default parameters that are provided in the software: this is because I have noticed that there is no possibility of restoring the factory values after having made the changes and saved them on the servo. Another thing: after having made the changes to the parameters you will first have to apply them (“derived parameter”) and then write on the servo (“writinbg device”) otherwise it seems not to go well…
The last thing that I have already mentioned is the fact that these servos are equipped with a 25mm aluminum bracket that is very nice and in the same color as the servo, but it is a bit short especially for those who want a lot of travel in the aileron and quote surfaces.

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Electrics / Re: Skywing Edge 540 91': electric is better!

« on: July 02, 2024, 18:08:24 PM »

Let's move on and sorry for the slowness... The Yantrs B0850MGX-E servo has an aluminum case, weighs 80 grams and has a reduced depth (measures 40x20x38mm); the rotation shaft has 2 classic bearings and is also pleasing to the eye. It can be powered from 6 to 8.4 volts developing a torque of 50kg at 8.4v (0.08s) and 46kg at 7.4v (0.09s), 36kg at 6v (0.12s). The rotation is 180° but adjustable via programmer.
In the application (downloadable online) to program the Yantrs servos you can find all the main values (more or less identical to other servos with similar characteristics) such as power, rotation angle, speed, servo center, dead zone, reverse, fail-safe etc. Furthermore, in the software there is also the possibility of applying different types of servo management modes depending on the Rx: in addition to the standard mode, there are SR, SSR, SFR, SXR, UR modes, each with min. parameters. pre-set PWM max and midle. I'm not very knowledgeable in this matter but I've read that they affect the amplitude of the servo's movement, power and speed.
By reading a little I understood that the SSR mode is the one that more than others manages to increase the responsiveness of the servo with shorter pulses, which theoretically allows you to increase the transmission speed to more than 384 Hz, thus allowing you to transmit the gear position to the servo more frequently, e.g. reduce what is called latency here (the time needed to propagate the change in position of the steering wheel to the change in position of the car's wheels).
However, it appears that there is currently no transmitter on the market that uses a 384Hz frequency…
These servos do not emit hum and thanks to the slow power delay function at start-up they move to the neutral position slowly without jerks. Operation appears smooth and without any hesitation. The equipment is also excellent and includes a very sturdy aluminum square with two slip-proof fixing bolts on the crown. Some doubts about the servo rubbers which are the traditional round ones while I would have preferred the more robust square ones. But it's a detail...

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Electrics / Re: Skywing Edge 540 91': electric is better!

« on: June 28, 2024, 14:53:02 PM »

New entry also for servos: Forza Yantrs!
We finish electronics setup of this model with the choice of servos to install which, given the size and weight of the model, as well as the large moving parts to manage, could only be up to the task. And the opportunity to carry out this test was perfect to "experiment" with a new line of servos with very interesting characteristics but which I didn't know existed until I came across some websites where they spoke very well about it . They are produced by a Chinese company (and this is obvious...) "Yantrs" which specializes in the research, design, development and creation of high-end products for RC remote control which has set itself the goal of putting them on the market at a cost that is currently as low as possible. I took a look at the Yantrs servo catalog and realized that, unlike many other companies, the Yantrs servo catalog is essential and designed to meet the needs of an increasingly demanding modeling market in terms of quality and price.
What struck me most when I started reading the characteristics of these servos is the particularity of the gears they mount which are not of a traditional shape but machined obliquely (called helical) which, say the Yantrs engineers, have the characteristic of engaging more gradually with smoother operation which helps reduce shock loads (so they should last longer...), more stable torque transmission with less noise and vibration. These types of gears, unknown in servos until recently, are now increasingly found in other brands in the RC world.
From the Yantrs catalog I chose the B0850MGX-E servo with brushless motor, programmable rotation angle, pitch resolution with 14bit processor and high precision thanks to a high resolution magnetic sensor (therefore no potentiometer present in the servo). Programming compatible with SR/SSR/SUR/SFR super fast mode.

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Electrics / Re: Skywing Edge 540 91': electric is better!

« on: June 24, 2024, 14:37:40 PM »

Here we go again. Let's continue with what concerns the regulator.
Before being used, the ZTW Mantis HV G2 (the factory settings are set for standard use of brushless motors for propeller aircraft) must be "taught" for the throttle stroke from 0 to 100 (min./max.) for optimize the acceleration curve. To do this, simply turn on the radio first and place the accelerator stick in the max position. (100%). Then connect the battery to the ESC and wait about 2 seconds after which the motor will emit two acoustic signals: at this point you will have to return the accelerator stick to the minimum position (0%); the success of the gas stroke detection operation will be confirmed by a new acoustic signal. This calibration procedure is similar to practically all ESCs but is essential for correct modulation of engine power. Finally, I would like to say a few more words about the convenience of the Android app which, with the Bluetooth module, is easy and intuitive and always at hand. The Bluetooth module can be left connected to the regulator even in flight but I am of the opinion that the less electronics you bring on the flight the better, so I remove it.
Finally, an important thing regarding the operation of a 28-pole (or more) engine like the Dualsky GA6000: someone asked me if my engine had jerks or hiccups when going from 0 to 100% throttle: as I have already replied privately, at the moment I have not noticed similar problems but to be sure I inquired directly from Dualsky who kindly replied that these "disturbances" are not engine malfunctions but can occur if you do not use the latest generation regulators that have 32-bit processors. And in fact my ZTW Mantis satisfies precisely these needs and goes very well...

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Electrics / Re: Skywing Edge 540 91': electric is better!

« on: June 24, 2024, 14:35:59 PM »

Thanks for your interest. As soon as I do the testing I'll let you know. But the time will not be short due to commitments... Follow me.