The Jumper T20 GEMINI is the third mannequin of the household, and as its title suggests comes with a built-in twin ELRS TX module. The T20G inherits the small type issue and full-size RDC90 gimbals of the T20S. On this evaluation, we’ll uncover all of the variations and whether it is price the additional cash.
When you delve into the RC passion, continuous purchases turn into a norm, whether or not changing a worn-out rig or assembly the rising calls for for enhanced efficiency. Based mostly on my expertise, the radio controller is essentially the most secure factor of all equipment, so investing upfront in a correct one is crucial. The Jumper T20 GEMINI will fulfill the necessities of any pilot for a few years to come back, particularly because it can be upgraded with an exterior TX module if a brand new customary is launched sooner or later.
ExpressLRS is among the most fun management hyperlinks, enhancing each day. ELRS GEMINI is a twin channel (2.4GHz OR 900MHz) radio system centered on a lot larger and secure LQ by concurrently transmitting packets in two frequencies to extend the possibility of receiving the pocket by the receiver. This expertise was launched in late 2023, and Jumper’s T20G is the primary radio controller with a built-in TX module that helps this customary.
JumperRC T20 GEMINI evaluation
Disclosure: I obtained this drone transmitter from JumperRC to check it and do an in-depth evaluation. Though the RC was provided without spending a dime, all opinions on this article stay my very own, with no affect from my accomplice.
The JumperRC T20 Gemini is available in a pleasant purse with the next equipment: a neck strap, USB-C datacharging cable, three spare pressure springs, flight mode button stickers, and a Fast Begin information. Moreover, they despatched me 4 units of CNC aluminum stick ends.
What makes the T20G distinctive just isn’t on the surface however inside. Until now, all radio controllers had solely monosolo ELRS modules constructed inside with a max energy of 1 watt. The T20G’s GEMINI ELRS TX module has a twin 1W transmission energy to offer the most effective anti-interference efficiency and stability. It’s the best radio for demanding purposes like FPV racing, Bando, and long-range flights. The TX firmware will be upgraded by means of the type-C connector or wi-fi by way of the built-in internet UI. After upgrading the TX software program, bear in mind to interchange the prevailing LUA script (elrsV3.lua) with the newer one.
Like all fashions of the T20 sequence, the Gemini version additionally runs on the favored open-source EdgeTX firmware. A speaker beneath the left gimbal ensures audible alerts and suggestions throughout your flights. It’s a cool characteristic in case you have the time to configure it nicely. The voice audio information are saved on the inner reminiscence; no micro SD card is required like within the case of different radios.
Key options
- Compact design with full-size gimbals and a wide range of controls (123 place switches, rotary knobsdials, sliders, and customizable flight mode buttons);
- Constructed-in Variety GEMINI-compatible 2x1000mW transmission module;
- OLED standing display;
- Lengthy Battery Life with two 21700 Li-ion cells;
- Coach port and USB HID work FPV simulators;
- Constructed-in reminiscence, no micro SD required.
Technical parameters
| Dimensions | ~10x50x12cm |
| Weight | 425 grams (with out batteries) |
| Show | 1.3″ OLED with 128*64 decision |
| Gimbals | Full-size RDC90 |
| Storage | Inbuilt 512 MB |
| Enter voltage | 6.0V – 8.4V |
| Battery choices | 2S LIPO, 2×18650, or 2×21700 Li-ion cells |
JumperRC T20 GEMINI: RX compatibility
The T20G will work with any 2.4 Ghz ELRS receiver on the identical main firmware launch. As an alternative, for full GEMINI compatibility, you will have a dual-RF true Variety ELRS RX module such because the BetaFPV SuperD or the RadioMaster RP4TD.
T20 GEMINI: Design, Ergonomics, and construct high quality
As an alternative of a gamepad-style design, the T20 sequence has a field type issue with an approximate measurement of 175x140x65 mm. With out batteries, the transmitter weighs 425 grams. Apart from the brand new foldable and rotatable double antenna (DFA), there’s not a lot change from the T20S on the entrance. It has the identical management format, OLED display, and RDC90 gimbals.
On that again, as an alternative of a metallic heatsink, now there’s a cooling fan (250 mW default threshold to begin). The exterior TX module’s extension port (information+XT30 energy plug) is in the identical place behind a plastic flap. The extension (NanoMicro) isn’t included within the bundle and have to be bought individually.
Gripping it comes effortlessly, and manipulating the controls requires no awkward finger maneuvers -everything is comfortably accessible. The backs of the handles have a pleasant non-slip rubberized end.
The general construct high quality is great for its price ticket. The DFA folds ingeniously, saving house throughout storage. A lot of the controls are labeled. The stick ends are replaceable (with m3 screw measurement), permitting customers to improve them for higher fill -whether they like pinch grip, thumbing, or hybrid pinching.
T20 GEMINI: Controls (Buttons/Switches/Knobs/Sliders/Dials/Trims)
The T20 GEMINI is essentially the most complicated radio controller I’ve ever had in my hand. In case you are a DJI pilot, you will have a map to navigate on the entrance panel 🙂 Along with the 2 gimbals, it has six backlighted configurable flight mode buttons, two sliders (S3 and S4), and two dials (S1 and S2). It has 4 tiny 5D trimming joysticks that can be programmed in EdgeTX as management momentary push buttons.
There are two 3-position switches on the entrance (one on every nook) and two 2-position switches on high (additionally within the corners). Moreover, you have got two shoulder metallic latching push buttons behind the sliders with a middle indent.
To regulate and configure the radio, there are three tiny buttons on the left and a scroll wheel on the best. To make an easy operation, the buttons have twin capabilities in keeping with the way you press them:
- Mannequin Setup (quick press), Radio Setup (lengthy press)
- Subsequent Web page (quick press), Final Web page (lengthy press)
- Again
I just like the included stickers with operate names (RTLACROAUTOCRUISE and so forth), enabling pilots to customise the six flight buttons to their wants. Right here, I ought to point out that the buttons double as charging indicators and visible results throughout energy ON/OFF.
T20 GEMINI: OLED standing display
My greatest downside with the T-Lite, the T20’s predecessor, was the backlit LCD display on which the tiny fonts have been barely seen. Whereas the display measurement remained the identical, the T20G now has an OLED display ( 1.3″ with 128*64 pixels) with superior readability even beneath direct daylight.
The principle cause I changed the Jumper T-Lite with the RadioMaster Zorro was the small display, so I’d have preferred to see a much bigger display on this new mannequin.
What batteries are supported by JumperRC T20 Gemini radio?
The T20 will be powered from 6.0V to eight.4V. It has a beneficiant battery bay (84x43x25mm) with a 3P XH2.54 connector. You should use a 2S LIPO battery (there’s room for 1800-3000mAh) or two 21700 batteries utilizing the included 2-cell LIION cage. You may as well use 18650 with this holder by pulling the contacts inwards to allow them to maintain the marginally shorter 18650 cells securely.
Energy Consumption broadly is determined by TX energy settings (15mW-1Watt) and Antenna modes (Single, Change, or GEMINI). Utilizing two 21700 4000mAh batteries, you may count on three to 10 hours of operation time. Enabling “Dynamic energy” within the ELRS LUA script provides you the most effective steadiness between transmission vary and battery life.
The lighter 18650 batteries are enough for a couple of hours of weekend flying, however those that fly all day and each day ought to use two 5000mAh 21700 LiIon cells.
Charging
The T20G has a built-in charging circuit, and the LIION cells will be recharged by means of the USB Sort-C port on high of the radio. Initially, I examined it with a 100W PD charger however found it was not supported. I might use it solely with legacy 5V USB chargers, identified to be tremendous gradual.
Optimum TX energy setting for Jumper T20 Gemini transmitter
As talked about, the T20G claims to have a max TX energy of 2x1000mW in Gemini mode. Setting the very best energy doesn’t essentially provide the finest vary and penetration. Don’t point out the potential for interference along with your digital FPV system that runs on a lot decrease energy (10-700mW).
ELRS vary take a look at outcomes present the potential for flying so far as 50 km at 100 mW. For the most effective vary, matching the orientation of RX and TX antennas is crucial. For me, 250mW (dynamic energy enabled) works finest and covers your entire FPV vary of my O3 Air Unit and Walksnail with no failsafe.
Oscar Liang, who additionally reviewed the T20G, measured solely 500 mW when a 1W energy output was chosen. Hopefully, that is an remoted downside of its evaluation pattern or a software program bug and never a {hardware} limitation on the ability supply aspect.
Pricing, availability, and equipment
The T20 transmitter will be ordered from JumperRC’s web site for $199.99 (it’s essential log in to see the value) or from in style on-line retailers comparable to RC-Wing, HobbyRC, NewBeeDrone, and Banggood. You possibly can decorate the T20 Gemini radio with a clear case and CNC Aluminum stick ends.
T20 GEMINI Variety: Who’s for?
Most FPV drone pilots will in all probability not use even half of the management choices out there on the Jumper T20G. As an alternative, giant-scale RC planes and turbine guys will admire the number of controls and the variety of channels. Channel trimming can also be useful for fixed-wing pilots however is principally ineffective for multi-rotor flying machines.
In case you are principally into proximity park flying, the additional worth for the GEMINI expertise benefits just isn’t justified. Additionally, in case your drones are geared up with “mono” ELRS modules, there can be no distinction for you.
T20 GEMINI vs T20S vs T20: What’s The Distinction?
JumperRC launched the T20S and T20 in the summertime of 2023 and the T20 GEMINI a couple of months later —the distinction between the primary two fashions being solely the gimbal (and, in fact, the value). The essential T20 has corridor sensor (magnetic area) gimbals, whereas the premium T20S boasts potentiometer (analog output) RDC90 gimbals. The newer T20 GEMINI additionally makes use of RDC90 joysticks, however the inner ELRS receiver now has Variety dual-transmission modules (2x1W) and double-folding antennas. To deal with the additional warmth, the GEMINI has a cooling fan on the again, as talked about earlier than.
Of the three, the T20 is the most affordable mannequin, priced at $109.99. For the RDC90 gimbal within the T20S, you will have to pay additional $30 bucks ($139.99). The T20G is the flagship mannequin of the sequence, and it’s priced at $199.99.
Jumper T20 GEMINI: Alternate options
If you need a feature-rich ELRS transmitter with built-in GEMINI capabilities, your solely possibility is that this T20G. In the event you don’t thoughts, use an exterior module such because the BetaFPV SuperG Nano TX that gives the identical transmission capabilities; you have got loads of good choices, even for much less cash.
RadioMaster Pocket is the closest in design and format issue to the T20 GEMINI. Priced for under $64.99, it is a wonderful finances various.
The RadioMaster TX16S and Jumper T14 are additionally nice alternate options however on a bigger type issue. If measurement and weight are extra important for you than additional functionalities, the Jumper T-Lite is a discount for mare $59.99.
