The Video Transmitter (VTX) is an important part of the FPV system, wirelessly transmitting digital camera photographs to FPV goggles. When choosing a 5.8GHz VTX, think about compact measurement, options, channel assist, and correct transmitting frequency, along with lengthy vary and excessive output energy, to make sure optimum flight efficiency and minimal interference for fellow pilots. By understanding these key components, you’ll be higher outfitted to decide on the optimum 5.8GHz VTX in your FPV drone and revel in a extra immersive and gratifying flying expertise.
Analog vs Digital FPV Methods
FPV methods may be categorized into two sorts: analog and digital.
Analog tools isn’t appropriate with digital FPV gear. Presently, there are three digital FPV methods: DJI, Walksnail, and HDZero. Cameras and VTXs designed for a selected digital FPV system are additionally incompatible with different digital FPV methods. In case you’re not sure about which FPV system to decide on, right here’s my evaluation explaining the professionals and cons of every system: https://oscarliang.com/fpv-system/
VTX Suggestions
On this part, I’ll advocate one of the best VTX for every FPV system for various functions.
DJI
Walksnail
Finest All-Round VTX |
Nice for Micro |
| Walksnail Avatar HD VTX V2 | Walksnail Avatar 1S Lite VTX |
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The Walksnail Avatar HD V2 VTX presents enhanced options corresponding to 32GB storage for onboard 1080p recording, Gyroflow assist for picture stabilization, a grounded heatsink to scale back GPS interference, and extra 20x20mm mounting choices for better body compatibility. Varied appropriate cameras can be found relying in your preferences for picture high quality, low gentle efficiency, or weight discount. As a budget-friendly various to DJI methods, Walksnail’s V2 VTX does have some drawbacks, corresponding to the dearth of an SD card slot for storage growth and 4K recording, and a single antenna design that might impression vary and penetration efficiency. |
The Walksnail Avatar HD Mini 1S Lite VTX, superb for micro drones corresponding to Tiny Whoops, boasts a compact design and weighs simply 8.7 grams along with the Lite nano digital camera. It presents 720p and 1080p HD FPV capabilities, together with 8GB of onboard storage for video recording. Nonetheless, the Mini 1S Lite VTX requires an enter voltage between 3.1V and 5V, so it could possibly both be powered instantly from a 1S LiPo battery or a 5V 2A BEC if you’re utilizing 2S batteries. Make sure the 5V BEC can provide enough present for optimum efficiency. |
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Product Pages:
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HDZero
Finest VTX for Freestyle and Lengthy Vary |
| HDZero Freestyle V2 |
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The HDZero Freestyle V2 VTX presents one of the best vary and penetration for the HDZero methods, because of its 1W transmit energy. Very best for aggressive freestyle and long-range flights, it options large heatsinks on either side for bodily safety and cooling. Out of the field, it helps 25mW/200mW, however with a HAM radio license, it may be unlocked as much as 1W utilizing particular firmware. The VTX weighs 22.3g and helps 2S-6S batteries direct energy, with SmartAudio and MSP Canvas Mode compatibility. |
| Discover the HDZero 1W Freestyle V2 VTX from these distributors
AliExpress: https://s.click on.aliexpress.com/e/_DkoyILh |
Gentle Weight Possibility |
Finest VTX for Micro Drones |
| HDZero Race V2 VTX | HDZero Whoop Lite |
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The HDZero Race V2 VTX is designed for racing, that includes a compact and light-weight design that matches on 20x20mm M3 mounting. It helps SmartAudio, permitting VTX settings modifications from Betaflight OSD and OpenTX/EdgeTX radios. The U.FL connector may be secured with a zipper tie to stop antenna detachment throughout crashes, and it has a built-in TVS diode for energy safety. Nonetheless, its 200mW output energy is modest and is probably not superb for long-range flights. This limitation isn’t vital for racing occasions, as most limit output energy to 25mW. |
The HDZero Whoop Lite VTX is the smallest and lightest VTX within the HDZero system, designed particularly for micro FPV drones like tiny whoops. Versatile with 1S to 3S energy assist, it may be powered instantly from most micro drone batteries. It additionally options SmartAudio for altering VTX settings in Betaflight OSD. When paired with the HDZero Nano Lite Digital camera (1.5g) and a 0.4g dipole antenna, this combo creates the world’s lightest digital FPV resolution, weighing beneath 7g in whole. |
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Product Pages: GetFPV: https://oscarliang.com/product-ee00 |
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Analog
Respectable Worth VTX |
Most Versatile Premium VTX |
| Rush Tank Final Plus | TBS Unify Pro32 HV |
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The 800mW excessive transmit energy VTX is a dependable selection for analog, placing stability between efficiency and value. The Rush Final Plus is right for builds with restricted area for an additional board within the FC stack. Nonetheless it additionally features a 30.5×30.5mm adapter for set up on prime of your FC if wanted. The built-in microphone is a bonus, permitting you to listen to the motors and beeper by your FPV goggles audio output. |
The TBS Unify Pro32 HV is a flexible premium VTX recognized for its correct output energy ranges, clear sign transmission, prime quality, and reliability. With as much as 1000mW output energy in a compact bundle, it’s good for lengthy vary, racing, or informal freestyle. The VTX additionally helps TBS Crossfire methods, permitting customers to alter channels and energy ranges by the Crossfire receiver. This function is very helpful for pilots and not using a flight controller or Betaflight OSD, like these flying fixed-wing plane. |
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Finest Lengthy Vary |
Least expensive Value Having |
| Rush Tank MAX SOLO (2.5W) / SOLO (1.6W) | Flywoo GOKU HM600 |
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For long-range pilots, the RushFPV Tank Solo presents probably the most highly effective VTX choices accessible within the FPV business. There are two variations, SOLO with as much as 1.6W output energy and the MAX SOLO with as much as 2.5W. Each VTX’s are enclosed in large CNC aluminium heatsink, which helps keep most output energy and prevents efficiency loss on account of overheating. The SOLO is fan-less which implies it’s lighter and extra compact in comparison with the MAX SOLO. |
The GOKU HM600 is a superb funds VTX possibility for inexpensive builds. Priced at simply $19.99, this compact VTX is filled with options that rival costlier choices. It presents a number of mounting patterns, together with 20x20mm, 25.5×25.5mm, and 30x30mm, accommodates a large enter voltage from 2S to 6S, helps 5 bands, and may output as much as 600mW. Its light-weight and compact design makes set up a breeze. |
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Get the GOKU HM600 VTX right here: Flywoo: https://oscarliang.com/product-fv8s |
Finances Smallest |
Premium Smallest |
| Happymodel ELRS Fyujon AIO Board | TBS Unify Pro32 Nano |
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The Happymodel ELRS Fyujon AIO Board is an inexpensive, compact 300mW VTX designed for micro drones. With 25.5×25.5mm, 20x20mm, and 16x16mm mounting choices accessible, it presents nice compatibility. Priced at simply $21, it contains each a VTX and an ExpressLRS 2.4GHz receiver, with all the combo weighing a mere 3g. This all-in-one resolution is ideal for tiny drones that lack a built-in VTX and RX within the flight controller. |
The TBS Unify Pro32 Nano is the final word selection for micro quads and Tiny Whoops should you’re in search of the smallest and strongest VTX. It holds the title for probably the most compact video transmitter in the marketplace, measuring simply 15x13x2mm and weighing a mere 1 gram. Regardless of its tiny measurement, the Pro32 Nano can ship a powerful output energy of as much as 500mW. Conveniently, it may be powered instantly from a 2S or 3S LiPo battery, making it a really perfect possibility when there’s no 5V supply accessible. |
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Picture High quality
Though VTX costs can fluctuate considerably, picture high quality is usually decided by your FPV digital camera, not the VTX. Paying a premium for a high-end VTX received’t dramatically enhance picture high quality usually. Nonetheless, choosing a VTX with wonderful options and dependable sign high quality can improve your general flying expertise.
Sign High quality
The principle components that contribute to FPV sign high quality and vary are the standard and placement of the antennas and the VTX’s accuracy in transmitting on the supposed frequency.
Increased-end analog VTXs supply extra correct transmit frequencies and cleaner alerts that intervene much less to the neighbouring channels. Antennas must be designed and tuned for a selected frequency vary.
Some digital VTXs supply twin antennas (variety), permitting you to mount them at a 90-degree angle to enhance sign high quality no matter your plane’s perspective throughout flight.
You may be taught extra in regards to the optimum antenna placement on this submit: https://oscarliang.com/antenna-positioning/
Antenna Connector
Most VTXs include antennas you’ll be able to merely plug in. Nonetheless, if you wish to improve or change them, it’s essential to know the connector kind your VTX comes with.
VTXs have varied connectors, with the most well-liked sorts being SMA, RP-SMA, IPEX (aka UFL), and MMCX.
SMA and RP-SMA
SMA and RP-SMA are the oldest connector utilized in FPV gear. They’re comparatively giant and threaded connector. There are two sorts, SMA and RP-SMA, be sure you match the connector kind with the suitable antenna.
You should utilize SMA to RP-SMA converters and adapter cables for incompatible connectors, however remember that there’s a small efficiency penalty for every adapter used. Typically a couple of % of sign loss, it’s not a lot.
UFL
IPEX or U.FL connectors are standard for smaller VTXs on account of their low profile design in comparison with SMA connectors. Nonetheless, they put on out extra shortly because of the a lot decrease mating cycles. You may join a U.FL to SMA pigtail to the VTX or use an antenna with a U.FL connector. This connector is smaller than SMA connectors and is press-fit into place, making it susceptible to coming unfastened in crashes, subsequently manufactures have a tendency to make use of glue or retention to safe it in place.
MMCX
MMCX strikes a stability between the delicate U.FL and ponderous SMA connectors. As a more recent connector kind, it’s a press-fit connector however a lot sturdier than UFL, making it much less more likely to come out throughout a crash. MMCX additionally has a better mating cycle depend than UFL. This design balances the tradeoffs between SMA’s sturdiness and U.FL’s measurement and weight. Nonetheless, discovering an MMCX antenna may be difficult because it’s not but as widespread as the opposite two connectors.
Powering VTX
Trendy video transmitters (VTX) usually assist a variety of enter voltages, permitting you to energy them instantly out of your drone’s battery (e.g., 4S and even 6S LiPo). Nonetheless, a well-liked strategy is to energy the VTX utilizing a voltage regulator on the flight controller, generally often called a BEC (Battery Elimination Circuit).
Not solely does a BEC convert increased voltage to a decrease one, however it additionally acts as a filter in your VTX’s energy provide. Drone batteries may be extremely noisy energy sources because of the noise generated by the ESC and motors. Nowadays, most flight controllers come outfitted with onboard BEC particularly designed to energy VTXs. They supply 8V, 9V, 10V, or 12V voltage output and have wonderful filtering circuitry to attenuate voltage spikes and electrical noise out of your energy system.
For instance, the Speedybee F405 V3 FC has a devoted 9V BEC for powering video transmitters.
One other important issue to think about when powering your VTX from a BEC (or any voltage regulator) is making certain it could possibly provide the required present for the VTX to perform appropriately. Producers don’t at all times embrace amp draw of their specs, which is why it’s useful to take a look at my evaluations as I at all times attempt to present information like this. An underpowered VTX may end in lowered vary or instability, affecting your general FPV expertise.
In case you select to energy your VTX instantly from the battery, be sure that it has correct energy filtering to stop noise and contours in your movies. A preferred filtering methodology is utilizing an LC filter or just including a low ESR capacitor on the energy enter.
Output Energy
The facility output of a video transmitter determines the quantity of vitality radiated by it. VTX output energy is measured in milliwatts (mW) or decibels milliwatts (dBm). Most VTXs have adjustable output energy, offering flexibility relying in your flying setting and preferences.
Increased Energy for Prolonged Vary
Typically, extra energy means extra vary; nonetheless, this comes with some downsides, corresponding to elevated warmth within the VTX and potential interference for different pilots. Moreover, every nation could have totally different authorized limits on the utmost output energy you’re allowed to transmit.
Usually, 25mW is great for indoor flying and flying with others, providing enough vary for many racing tracks. Alternatively, pilots have a tendency to make use of increased output energy when flying outside for a extra dependable hyperlink and to fly additional. Remember the fact that growing output energy leads to diminishing returns in vary enchancment, because it takes 4 occasions the facility to double the vary. Discover ways to calculate vary on this tutorial: https://oscarliang.com/calculate-fpv-range/
Downsides of Excessive Output Energy
Increased output energy additionally generates extra warmth, which may trigger VTXs to overheat, impacting efficiency and even shutting down mid-flight in excessive circumstances. Excessive energy isn’t at all times superb in environments with vital multipath interference, corresponding to garages and stadiums, the place alerts can bounce off concrete or metallic surfaces. In these conditions, it is smart to make use of a decrease output energy.
When flying with a bunch, it’s finest to keep away from high-power VTXs, as they will bleed into different pilots’ video feeds, making it tough to fly collectively. Most racing occasions require pilots to run 25mW VTXs.
Antennas: Equally or Extra Vital
Along with your VTX’s output energy, the antennas in your transmitter and FPV goggles or receiver considerably impression your vary and sign high quality. With an optimum antenna setup, 25mW has been confirmed to have the ability to obtain over 5km of vary, whereas 400mW ought to be capable to deal with 4 occasions of that (over 20km) in superb situations. Many components, corresponding to interference, antenna alignment and placement, can impression your most vary too. To be taught extra about FPV antennas, take a look at this tutorial: https://oscarliang.com/best-fpv-antenna/
Understanding VTX Channels
VTX channels are preset frequencies you need to use to broadcast your video again to the video receiver. To determine a connection, choose the identical channel on each the video transmitter and video receiver. 5.8GHz (5800MHz) is the popular frequency band for FPV as a result of it’s authorized in lots of nations, and the antennas may be made fairly small.
Within the analog system, there are 5 bands: A, B, E, F (Fatshark), and R (Raceband), with eight channels per band. This offers you a complete of 40 channels to select from. Whereas these are the most typical bands, there are others, however not all frequencies are authorized to make use of. Nonetheless, some channels overlap between totally different bands, so you’ll be able to’t have 40 folks flying concurrently. The truth is, it’s fairly a problem to have simply 8 folks flying on the similar time. To maximise the variety of pilots within the air with out interference, it’s key to make use of good high quality VTX that has clear sign, and guarantee to allocate channels with sufficient frequency separation.
For digital FPV methods, channel administration is easier, as a result of there is only one band accessible (solely 8 channels), and it’s simpler to handle. These channels fall inside the similar or comparable frequencies because the analog Raceband channels.
That is Walksnail Avatar’s channel choice display screen contained in the FPV Goggles.
In case you fly alone, you don’t want to fret about which VTX channel to make use of—simply decide any! Nonetheless, when flying with others, it’s important to allocate channels fastidiously to attenuate interference. To be taught extra about selecting the right FPV channel, take a look at this submit: https://oscarliang.com/fpv-channels/#choosing-a-channel-in-analog
Onboard Microphone
By having a microphone within the drone lets you take heed to the motors, which some pilots argue makes them really feel extra linked to the drone, particularly when flying at distances the place the drone’s sound is now not audible. For extra particulars, go to: https://oscarliang.com/microphone-fpv/
Producers of digital FPV methods typically don’t embrace onboard microphones of their VTX designs. Nonetheless, some analog VTXs and FPV cameras have built-in microphones should you want to incorporate this function in your FPV setup.
Key Concerns for Analog VTX
Whereas analog video high quality pales compared to digital methods, with its blurry, low-resolution, and noisy photographs, it stays standard on account of its extensive availability, low value, compact measurement, and low latency. One other key benefit of analog methods is their compatibility, permitting you to simply swap video transmitters from totally different manufacturers with each other.
Basically any analog VTX will suffice for freshmen, however when flying with others, it’s essential to have a high-quality one. Some low-quality, generic VTXs have “soiled” alerts that scatter past the really set channel into different frequencies, doubtlessly interfering with different pilots’ alerts.
Altering VTX Settings
There are a number of strategies to alter channels, bands, and energy settings in your VTX.
Virtually all VTXs today include a push button for altering channels and adjusting different settings. Nonetheless, because of the single button and restricted standing indicators (LED lights), this process may be complicated and sophisticated.
Essentially the most environment friendly methodology for altering analog video transmitter settings is utilizing Betaflight OSD. In case your VTX helps SmartAudio or Tramp protocols, you’ll be able to observe this information to arrange VTX Management: https://oscarliang.com/vtx-control/
Pitmode
Pitmode is an important function for many who race or typically fly with different pilots. It permits the output energy of your VTX to drop to an especially low degree (virtually zero) when your quad is powering on or has crashed. This fashion, you’ll be able to change your VTX settings or retrieve your quad with out disrupting different pilots who may nonetheless be within the air.
Connecting an Analog FPV Digital camera to a VTX
Wiring an analog video transmitter in your drone could fluctuate relying on the parts concerned. At its most elementary, a VTX requires 3 connections: video enter, energy, and floor.
To attach the FPV digital camera on to a VTX, join the sign wires and guarantee you may have a working video receiver on the identical channel in your FPV goggles to obtain a picture. If the FPV digital camera and VTX are powered from totally different sources, additionally join their floor wires.
A typical method to join a VTX is thru the flight controller if it has a built-in OSD chip. You’ll discover a video enter (Vin) on the flight controller to attach the digital camera sign and a video output (Vout) on the flight controller to hook up with the VTX.
Be sure you present the proper voltage to your VTX to keep away from damaging or under-powering it. You may usually energy your VTX instantly out of your flight controller if it has a BEC (a built-in voltage regulator that provides both 5V, 9V, or 12V, and so forth.). Most VTXs these days assist a variety of enter voltage, so that you may be capable to energy them instantly from a LiPo battery.
Finest Practices Utilizing VTX
By no means Energy Up VTX with out an Antenna
All the time bear in mind to attach an antenna to your VTX earlier than powering it up. In case you energy up your VTX with out an antenna, the vitality has nowhere to flee, inflicting warmth to construct up within the transmitter. Over time, this extra warmth can harm the VTX.
Tips on how to Keep away from Noisy Video
Motors and ESCs can generate a major quantity {of electrical} noise in your energy system, which may introduce noise into your video feed. In case you energy your FPV gear (e.g., VTX and digital camera) instantly from the battery, electrical noise could cause interference, leading to white traces or flickering throughout the display screen.
To troubleshoot and stop these points, think about the next:
- Add additional low ESR capacitors to scale back noise within the energy system should you haven’t already. These capacitors might help filter out {the electrical} noise created by the ESCs and motors, making certain a cleaner video feed.
- Correctly handle your wiring, grounding, and energy distribution. Maintain video sign and energy wires as far aside as doable, and use twisted or shielded cables to attenuate interference.
- Use a devoted voltage regulator or an LC filter in your VTX and digital camera. This might help cut back noise and stabilize the facility provide, leading to a cleaner video feed.
For extra detailed info on the way to repair FPV noise, please refer to those articles:
Keep away from Contact between VTX Antenna Floor and Body
Some drone frames function a gap within the carbon fibre that lets you mount the SMA antenna connector on to the body. Nonetheless, this creates contact between the antenna floor and the carbon fibre body, which is conductive. If any dwell wire touches the carbon fibre body, it may doubtlessly fry your VTX. Moreover, this contact could cause noise to back-feed into the system, resulting in a spread of points, together with VTX overheating on account of elevated resistance.
Conclusion
In conclusion, understanding the ins and outs of video transmitters is essential for an optimum FPV expertise. This information has coated important facets of video transmitters, together with output energy issues, channels and frequency, the way to change VTX settings, and one of the best practices for correct use.
By following these pointers and suggestions, you may make knowledgeable selections when selecting and establishing your video transmitter for each informal {and professional} flying. Finally, mastering the usage of VTXs will guarantee a seamless and gratifying FPV expertise, permitting you to discover the skies with confidence and precision.
Edit Historical past
- Apr 2016 – Article created
- Apr 2017 – Article up to date, added “digital FPV system”, “sensible audio and telemetry function”, “10 bands, 80 channels”
- March 2018 – Article up to date with information about antenna connectors, VTX Management, energy and sign connection
- Oct 2019 – Up to date information about connection
- Dec 2022 – Up to date part about output energy
- Apr 2023 – Article revisited, added product suggestions, shortened URL
- Mar 2024 – Up to date merchandise
