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:

sz_tsetup

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Latency comparison on screens (for HMD-FPV use)

I noticed slightly increased latency when flying with my HMD’s, compared to my old cinemizers (plus, not OLED). Not critical, flyable – but noticeable on corners and flying over obstacles at high speed.

Had few screens around, measured latency (just to remind – @25FPS one frame takes 40ms; at 50km/h you fly ~1.4m over 100ms), only few screens provided, i did > 100 photos and averaged:

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5.8G analog receiver comparison (RX5808, RX5880 modules suitable for FPV and FR632 RX)

While 1.2G video is working very well for flying around obstacles, it also has own limitations. 2.4G video is somewhere in middle – small VTX, smaller antennas and good enough penetration, but unsuitable for flying in city (WiFi everywhere) and in meetings (2.4G RC adds a lot of noise even on 2370/2510 channels).

So, i moved back to 5.8G with some of my copters. Did simple RSSI-based diversity, added RX5808 modules to my HMD… Works good enough for everyday flying, but i noticed, that my friend can fly further using FR632 RX. LOS Range is acceptable for both, but he was flying further over obstacles  and in buildings.

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Antennas for mini-copter – what we can do?

Long story short – started with 5.8GHz on mini FPV copter (pocket rocket quad), soon got another, tried 1.2GHz (see earlier videos here) and finally picked 2.4GHz for my video.

Things change with time, Lithuania now has #1 Wi-Fi coverage/speed in the world and now i found that 2.4GHz for video usually has lower range than old 5.8GHz setup. It still works fine in forests or far far away from populated places, but flying in city is next to impossible (for example, Vilnius Old Town, near Užupio Kūdrų parkas – loosing video in 20m away from me, using 2370MHz or 2510MHz which should be away from common Wi-Fi range).

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