Tag Archives: vtx

VTX power comparison – quick run #3


Got several new 5.8G VTX’es and decided to test their power output. Quick table for reference, but see notes below:

VTX dBm mW Comments
Aomway #1 (fat pigtail)
8 6,3
22 158,5
Aomway #2 (thin pigtail)
5 3,2
24 251,2
Aomway 4″ copter
-13 0,1 Dead PA…
-15 0 Dead PA
RP-SMA DIP BG: http://www.banggood.com/Skyzone-FPV-TS5813S-5_8G-25mW-40CH-Mini-AV-Wireless-Transmitter-For-Mini-Multicopter-QAV250-p-1021364.html
10 10
Foxeer 600mW:
23 199,5
Foxeer 200mW:
24 251,2
Foxeer switcher:
11 12,6 (floating – pwr1)
13 20 (floating – pwr2)
13 20 (floating – pwr3)
600mW: http://www.surveilzone.com/58G-32CH-AV-600mW-Mini-VTx-for-DJImini-Multirotor-g-1303
26 398,1
TS58400: http://www.banggood.com/Skyzone-TS58400-5_8G-400mW-32CH-AV-Transmitter-Module-p-1004170.html
24,5 281,8 (stable)
ET526: http://www.banggood.com/Eachine-ET526-5_8G-40CH-25mW200mW600mW-Switchable-FPV-Transmitter-p-1075702.html
13 20
22 158,5
26,5 446,7 Hot
FT48X: http://www.himodel.com/FPV_Telemetry/FPV_5.8G_0.25-600mW_Adjustable_48-Channel_A_V_Transmitter_VTX_FT48X.html
13 20 (stable)
21 125,9 (stable)
25,5 354,8 (stable, veryhot)
-5 0,3

In short:

  • My equipment is not calibrated for absolute power output, but is precise enough (~1dB) for relative power output. Have that in mind when comparing power output between different measurements.
    In other words – relative output between VTX’es is precise. Exact power (for example, 300mW) may be off (may be somewhere in 3dB range).
  • All measurements done at A1 channel (5865MHz), 2 minutes after powering up, stock heatsinks and no airflow; 20x 1-second sweep iterations, max power average
  • Third switchable (25/200mW) Aomway which dies in the same way. No, it was not powered without antenna. Sometimes PA just dies for some reason and it becomes unusable (module is sold on taobao, but not on public-accessible places, so… Expensive and useless)
  • Foxeer 600mW sucks, but nothing new (see earlier post about it)
  • Foxeer switcher is useless – switching maybe internal heat generator, but not power output. But note – i have first version, with SMA on side. Second version (SMA in middle) may work better (and yes, i unpowered/powered it back after changing power setting). Also, it’s power is jumping in +/-6dBm range all time, really random-power VTX
  • TS58400 is something i like for mid-range mini-airplanes. It’s compact, no excessive heating (but i’m using small heatsinks on 2 of them), has very stable power output (all other VTX’es change power with time due to heating) and very stable frequency. Too much power for race copters, but nice stuff for mid range
  • ET526 is nice, starts-up at zero power, need to press button to power up. Heats up a lot at max power setting, airflow required (or at least heatsink). Two buttons for configuration and strange channel layout (A1 == C1 here, etc)
  • FT48X – VTX with 5.3G band! Startup at 25mW, which may be good and bad at the same time, depends ;-) Two minor issues with it – very hot at max power (the same as ET526) and “no RF power setting” is actually “Low RF power”, which is still flyable few meters around (~15m range with omni antennas), so you MAY kill someone on race with that “no power mode”. Other than this… Nice VTX with mic.

Surveilzone (Foxeer)/Aomway VTX comparison

Got ~10x Surveilzone (Foxeer) VTX’es around, from 25mW to 600mW, also 25/200mW Aomway and decided to check what’s inside.

Testing setup – RFE + attenuator chain. 60dB attenuation + 3dB offset in RFE, so in total you need to add ~63dB to visible averaged result on graph. All tests done on C1 channel (5705MHz).

Absolute power ouput is not precise, relative – much better (0.5dBm or better).

Cold testing – ~10s after powering on (already full averaged cycle), hot – after 5 minutes on my desk.

This looks like:


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