An Extremely Tiny 5.8GHz FPV Transmitter

Flying RC aircraft with a first person view is the latest and greatest thing in the hobby. In a fact that I’m sure will be shocking to 90% of people, you don’t need to buy a Phantom quad fly FPV. The guys at Flite Test show how you can build a tiny 5.8GHz FPV transmitter for under $100.

The parts used for this build are pretty much jelly bean parts at this point, but [Peter] at Flite Test is going for extremely lightweight parts for this build. He found an NTSC board camera that only weighs 1g and added a wide-angle lens. The transmitter is a tiny 200mW module that only weighs about 2g.

Why are the Flite Test crew going for small and light FPV setups? They just launched a new line of planes that can be built from a single piece of foam board. If you have a small micro quad, you can easily add FPV to it with this rig.

19 thoughts on “An Extremely Tiny 5.8GHz FPV Transmitter

      1. If you keep the voltage at the correct levels it is warm but just over skin. I have a calibrated VTX power meter so I could see the output and adjust the voltage regulator to get the sweet spot.

  1. They are telling you that they accidentally got the 5v variant that has an LDO regulator on-board and that you should get the 3.3v variant. But the 3.3 one says not to exceed 3.6v max, aren’t some lipo cells 3.7v?

    It will probably be fine but it is a slight inconsistency.

  2. Yeah, that would end with the Nosmoke.exe needing to be reinstalled.

    I did find out that some video glasses notably the Myvu Crystal are very fussy about voltage, give them 3.4V instead of 3.3 and they display garbled video.

    Someone needs to do a “How to make your own ISM certified 5.8GHz video xmitter” page, it cannot be that hard using say recycled satellite LNB bits and some sort of dielectric resonance oscillator (DRO) utilizing a 2.4 GHz Bluetooth antenna as the active part with a first harmonic filter and PA stage.

    1. The “ISM Certified” part of that is the hard one. thousands of USD in testing, measurement and certification.
      On the subject of 5.8GHz FM video TX with scraps, I think the easier one to do would be using 5.77GHz DRO’s used in some C-band satellite TV LNB’s (so they should be cheap) and a simple LTCC low pass filter at the output. And some cheap transitors like BFP405 or BFU730f for active devices.
      But it seems that the chinese manage to get the PLL’s used in the transmitters to be cheaper than even a cheap DRO oscillator.
      But it would certainly be an interesting design exercise.

  3. You can drop 3.7 to 3.3V with two Schottky diodes in series, I use the 150mV ones off Ebay labelled 1N581x.
    1N5817 will work but so will any moderately small SMPS salvaged diode.
    I even used this to fix my Geiger counter as 1N581x’s have a well defined 150V reverse breakdown voltage provided the current is low (ie less than 100uA)

  4. A LDO (not from China) is $0.50 a piece. I think I saw $3 for 10 LDO from China. Why not use the right part?

    BTW I am cheesed off when the USB in my hub blew up because I rearranged the order. It turns out someone used 2 silicon diode for 5V to 3.3V conversion. Sorry dude, the diode drop voltage has a large variation as do USB voltages. Same can be said about charged LIPO. Diode drops can change very drastically if your device goes into ultra low power to transmit mode. It is exponential BTW.

    1. I think so. I ordered a board based on the ts5823 chip, which is a bit bulkier than Peter’s solution. Can take lipo voltage directly, has RP-SMA connector soldered on, and was only 24 euro’s including shipping to the Netherlands. You can go cheaper on AliExpress, but not much.

      It’s gonna go on a tricopter, with plenty of lift :-)

  5. Damn, 200mW on this freq is way to much to use in EU.
    F.ing MEP communist bustards, they always regulate and prohibit something to make people’s everyday life much harder, and their and the lobbyists’ live more profitable.
    Lastly they debated over the maximum hoover power and also over the maximum amount of water You can use when flushing your toilet.
    When will this madness end?

  6. Has anyone tried surface mounting one of these boards? I’m trying to learn Eagle but I haven’t had a spare evening to learn it. I want to design a board with surface mount LC filter.

  7. Putin would be doing us a favour if he invades. Long Live the Glorious Russian Federation Comrades!!
    Take back the yoke of communism from these neo-capitalist scumbagskis in Brussels!!

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