The Video Transmitter (VTX) is an important part of the FPV system, wirelessly transmitting digital camera pictures to FPV goggles. When deciding on a 5.8GHz VTX, take into account 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 on your FPV drone and luxuriate in a extra immersive and pleasant flying expertise.
Analog vs Digital FPV Methods
FPV programs might be categorized into two varieties: analog and digital.
Analog tools is just not appropriate with digital FPV gear. Presently, there are three digital FPV programs: DJI, Walksnail, and HDZero. Cameras and VTXs designed for a selected digital FPV system are additionally incompatible with different digital FPV programs. In the event you’re not sure about which FPV system to decide on, right here’s my evaluate explaining the professionals and cons of every system: https://oscarliang.com/fpv-system/
VTX Suggestions
On this part, I’ll suggest 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 affords enhanced options akin to 32GB storage for onboard 1080p recording, Gyroflow assist for picture stabilization, a grounded heatsink to cut back GPS interference, and extra 20x20mm mounting choices for larger body compatibility. Numerous appropriate cameras can be found relying in your preferences for picture high quality, low mild efficiency, or weight discount. As a budget-friendly various to DJI programs, Walksnail’s V2 VTX does have some drawbacks, akin to the dearth of an SD card slot for storage enlargement and 4K recording, and a single antenna design that might impression vary and penetration efficiency. |
The Walksnail Avatar HD Mini 1S Lite VTX, ideally suited for micro drones akin to Tiny Whoops, boasts a compact design and weighs simply 8.7 grams along with the Lite nano digital camera. It affords 720p and 1080p HD FPV capabilities, together with 8GB of onboard storage for video recording. Nevertheless, the Mini 1S Lite VTX requires an enter voltage between 3.1V and 5V, so it may well both be powered straight from a 1S LiPo battery or a 5V 2A BEC in case you are utilizing 2S batteries. Make sure the 5V BEC can provide enough present for optimum efficiency. |
| Get the Walksnail VTX V2 from:
AliExpress: https://s.click on.aliexpress.com |
Product Pages:
Caddx: https://oscarliang.com/product-d75h |
HDZero
Finest VTX for Freestyle and Lengthy Vary |
| HDZero Freestyle V2 |
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The HDZero Freestyle V2 VTX affords one of the best vary and penetration for the HDZero programs, due to its 1W transmit energy. Preferrred for aggressive freestyle and long-range flights, it options huge 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 adjustments from Betaflight OSD and OpenTX/EdgeTX radios. The U.FL connector might be secured with a zipper tie to forestall antenna detachment throughout crashes, and it has a built-in TVS diode for energy safety. Nevertheless, its 200mW output energy is modest and might not be ideally suited for long-range flights. This limitation is just not important 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 straight from most micro drone batteries. It additionally options SmartAudio for altering VTX settings in Betaflight OSD. When paired with the HDZero Nano Lite Digicam (1.5g) and a 0.4g dipole antenna, this combo creates the world’s lightest digital FPV answer, weighing underneath 7g in whole. |
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Product Pages: GetFPV: https://oscarliang.com/product-ee00 |
Get the HDZero Whoop Lite from: RDQ: https://oscarliang.com/product-x3g9 |
Analog
First rate 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 alternative for analog, placing an excellent steadiness between efficiency and price. The Rush Final Plus is right for builds with restricted area for an additional board within the FC stack. Nevertheless 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 via your FPV goggles audio output. |
The TBS Unify Pro32 HV is a flexible premium VTX identified for its correct output energy ranges, clear sign transmission, top quality, and reliability. With as much as 1000mW output energy in a compact package deal, it’s good for lengthy vary, racing, or informal freestyle. The VTX additionally helps TBS Crossfire programs, permitting customers to vary channels and energy ranges via the Crossfire receiver. This characteristic is particularly 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 Price 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 affords essentially 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 huge CNC aluminium heatsink, which helps keep most output energy and prevents efficiency loss attributable to overheating. The SOLO is fan-less which suggests it’s lighter and extra compact in comparison with the MAX SOLO. |
The GOKU HM600 is a wonderful finances VTX possibility for inexpensive builds. Priced at simply $19.99, this compact VTX is full of options that rival costlier choices. It affords 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 |
Price range 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 affords nice compatibility. Priced at simply $21, it consists of each a VTX and an ExpressLRS 2.4GHz receiver, with all the combo weighing a mere 3g. This all-in-one answer is ideal for tiny drones that lack a built-in VTX and RX within the flight controller. |
The TBS Unify Pro32 Nano is the last word alternative for micro quads and Tiny Whoops in case you’re searching for the smallest and strongest VTX. It holds the title for essentially 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 straight from a 2S or 3S LiPo battery, making it a really perfect possibility when there’s no 5V supply accessible. |
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Discover the Happymodel ELRS Fyujon AIO Board right here: AliExpress: https://s.click on.aliexpress.com/ |
Retailers: AE: https://s.click on.aliexpress.com/e/_DdeBxKh |
Picture High quality
Though VTX costs can differ considerably, picture high quality is generally decided by your FPV digital camera, not the VTX. Paying a premium for a high-end VTX gained’t dramatically enhance picture high quality most often. Nevertheless, deciding on a VTX with wonderful options and dependable sign high quality can improve your total flying expertise.
Sign High quality
The primary 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 meant frequency.
Greater-end analog VTXs provide extra correct transmit frequencies and cleaner indicators that intrude much less to the neighbouring channels. Antennas needs to be designed and tuned for a selected frequency vary.
Some digital VTXs provide 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 study extra in regards to the optimum antenna placement on this put up: https://oscarliang.com/antenna-positioning/
Antenna Connector
Most VTXs include antennas you’ll be able to merely plug in. Nevertheless, if you wish to improve or exchange them, it’s essential to know the connector kind your VTX comes with.
VTXs have numerous connectors, with the preferred varieties 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 use SMA to RP-SMA converters and adapter cables for incompatible connectors, however remember that there’s a small efficiency penalty for every adapter used. Usually just a few % of sign loss, it’s not a lot.
UFL
IPEX or U.FL connectors are fashionable for smaller VTXs attributable to their low profile design in comparison with SMA connectors. Nevertheless, they put on out extra rapidly 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 liable to coming free in crashes, due to this fact manufactures have a tendency to make use of glue or retention to safe it in place.
MMCX
MMCX strikes a steadiness between the delicate U.FL and hulking 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 the next mating cycle rely than UFL. This design balances the tradeoffs between SMA’s sturdiness and U.FL’s measurement and weight. Nevertheless, discovering an MMCX antenna might be difficult because it’s not but as frequent as the opposite two connectors.
Powering VTX
Fashionable video transmitters (VTX) usually assist a variety of enter voltages, permitting you to energy them straight out of your drone’s battery (e.g., 4S and even 6S LiPo). Nevertheless, a well-liked method 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, nevertheless it additionally acts as a filter on your VTX’s energy provide. Drone batteries might 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 reduce 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 guaranteeing it may well provide the required present for the VTX to operate accurately. Producers don’t all the time embody amp draw of their specs, which is why it’s useful to take a look at my critiques as I all the time attempt to present information like this. An underpowered VTX would possibly lead to lowered vary or instability, affecting your total FPV expertise.
In the event you select to energy your VTX straight from the battery, make sure that it has correct energy filtering to forestall 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 ability output of a video transmitter determines the quantity of power radiated via 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 surroundings and preferences.
Greater Energy for Prolonged Vary
Usually, extra energy means extra vary; nevertheless, this comes with some downsides, akin to elevated warmth within the VTX and potential interference for different pilots. Moreover, every nation could have completely 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 adequate vary for many racing tracks. Alternatively, pilots have a tendency to make use of increased output energy when flying outdoor for a extra dependable hyperlink and to fly additional. Understand that growing output energy ends in diminishing returns in vary enchancment, because it takes 4 instances the ability to double the vary. Discover ways to calculate vary on this tutorial: https://oscarliang.com/calculate-fpv-range/
Downsides of Excessive Output Energy
Greater output energy additionally generates extra warmth, which may trigger VTXs to overheat, impacting efficiency and even shutting down mid-flight in excessive instances. Excessive energy isn’t all the time ideally suited in environments with important multipath interference, akin to garages and stadiums, the place indicators can bounce off concrete or metallic surfaces. In these conditions, it is sensible 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’ll 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 Essential
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 have the ability to deal with 4 instances of that (over 20km) in ideally suited circumstances. Many components, akin to interference, antenna alignment and placement, can impression your most vary too. To study extra about FPV antennas, try this tutorial: https://oscarliang.com/best-fpv-antenna/
Understanding VTX Channels
VTX channels are preset frequencies you should use to broadcast your video again to the video receiver. To ascertain 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 international locations, and the antennas might 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. Nevertheless, some channels overlap between completely different bands, so you’ll be able to’t have 40 individuals flying concurrently. The truth is, it’s fairly a problem to have simply 8 individuals 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 programs, channel administration is less complicated, as a result of there is only one band accessible (solely 8 channels), and it’s simpler to handle. These channels fall throughout the similar or related frequencies because the analog Raceband channels.
That is Walksnail Avatar’s channel choice display screen contained in the FPV Goggles.
In the event you fly alone, you don’t want to fret about which VTX channel to make use of—simply choose any! Nevertheless, when flying with others, it’s important to allocate channels rigorously to reduce interference. To study extra about choosing the right FPV channel, try this put up: https://oscarliang.com/fpv-channels/#choosing-a-channel-in-analog
Onboard Microphone
By having a microphone within the drone lets you hearken to the motors, which some pilots argue makes them really feel extra related 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 programs usually don’t embody onboard microphones of their VTX designs. Nevertheless, some analog VTXs and FPV cameras have built-in microphones in case you want to incorporate this characteristic in your FPV setup.
Key Concerns for Analog VTX
Whereas analog video high quality pales compared to digital programs, with its blurry, low-resolution, and noisy pictures, it stays fashionable attributable to its large availability, low price, compact measurement, and low latency. One other key benefit of analog programs is their compatibility, permitting you to simply swap video transmitters from completely different manufacturers with each other.
Basically any analog VTX will suffice for rookies, however when flying with others, it’s essential to have a high-quality one. Some low-quality, generic VTXs have “soiled” indicators that scatter past the truly set channel into different frequencies, doubtlessly interfering with different pilots’ indicators.
Altering VTX Settings
There are a number of strategies to vary channels, bands, and energy settings in your VTX.
Virtually all VTXs as of late include a push button for altering channels and adjusting different settings. Nevertheless, because of the single button and restricted standing indicators (LED lights), this process might be complicated and complex.
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 characteristic for many who race or typically fly with different pilots. It permits the output energy of your VTX to drop to an especially low stage (virtually zero) when your quad is powering on or has crashed. This manner, you’ll be able to change your VTX settings or retrieve your quad with out disrupting different pilots who would possibly nonetheless be within the air.
Connecting an Analog FPV Digicam to a VTX
Wiring an analog video transmitter in your drone could differ relying on the elements concerned. At its most simple, 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’ve 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 completely different sources, additionally join their floor wires.
A typical solution 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 straight out of your flight controller if it has a BEC (a built-in voltage regulator that provides both 5V, 9V, or 12V, and many others.). Most VTXs these days assist a variety of enter voltage, so that you would possibly have the ability to energy them straight 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 the event you energy up your VTX with out an antenna, the power has nowhere to flee, inflicting warmth to construct up within the transmitter. Over time, this extra warmth can harm the VTX.
Keep away from Noisy Video
Motors and ESCs can generate a big quantity {of electrical} noise in your energy system, which may introduce noise into your video feed. In the event you energy your FPV gear (e.g., VTX and digital camera) straight from the battery, electrical noise could cause interference, leading to white traces or flickering throughout the display screen.
To troubleshoot and forestall these points, take into account the next:
- Add additional low ESR capacitors to cut back noise within the energy system in case you haven’t already. These capacitors may also help filter out {the electrical} noise created by the ESCs and motors, guaranteeing a cleaner video feed.
- Correctly handle your wiring, grounding, and energy distribution. Preserve video sign and energy wires as far aside as attainable, and use twisted or shielded cables to reduce interference.
- Use a devoted voltage regulator or an LC filter on your VTX and digital camera. This may also help cut back noise and stabilize the ability provide, leading to a cleaner video feed.
For extra detailed info on find out how to repair FPV noise, please refer to those articles:
Keep away from Contact between VTX Antenna Floor and Body
Some drone frames characteristic a gap within the carbon fibre that lets you mount the SMA antenna connector on to the body. Nevertheless, this creates contact between the antenna floor and the carbon fibre body, which is conductive. If any stay 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 attributable to elevated resistance.
Conclusion
In conclusion, understanding the ins and outs of video transmitters is essential for an optimum FPV expertise. This information has lined important elements of video transmitters, together with output energy concerns, channels and frequency, find out how to change VTX settings, and one of the best practices for correct use.
By following these pointers and suggestions, you may make knowledgeable choices when selecting and organising your video transmitter for each informal {and professional} flying. Finally, mastering the usage of VTXs will guarantee a seamless and pleasant 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”, “good audio and telemetry characteristic”, “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