RC radio 2.4GHz reliability and options

2.4G band use increasing

I have done a lot of surveying around my area, noting a big increase in 2.4G wifi over the last couple of years. What you can easily detect with a phone or laptop is only the tip of the iceberg. With a decent antenna or a better view point there is a lot more. We recently noted 8 or 10 wifi networks within about 600 meters of our club field, occupying the whole band and doubling up. And the field is mostly rural on 3  sides.

A model plane has the best vantage point to see or be bombarded with every 2.4G signal in the area.

Another thing to consider is that the “quality” or cost of the 2.4G radio has little to do with the reliability of the radio link. A $2K branded set uses pretty much the same radio gear as a $40 Chinese set. If the band is already full of other signals, smarter frequency hopping won’t help much.

2.4G video senders put out a wide band “interference” signals. I’ve done a drive around with my FPV ground station and it’s interesting how many TV and security camera senders there are. Not very good security really; when you bug your own building with video 🙂 Confirmed, they’ve gone home, jamb the signal, let’s go in….

Long Wire RC

The lower MHz systems could frequency hop but probably not ideal. The data rate per channel would be low compared with 2.4G and the hopping overhead would slow it further. A better solution would be to use 2 or even 3 receivers in parallel and have a backup channel.

I’m still using mostly 35MHz, where the channels are supposed to be dedicated to RC planes. But there are a couple of park sites locally where it can’t be trusted. On the low MHz, it’s not really a band but a set of allocated narrow-band channels and I think there are other users in the gaps and maybe even occasional bounce coming from a low way away.

433 MHz ISM band

The 433MHz ISM band is shared with Ham radio. The free part is really small. This ISM band is also becoming very busy with burst, Spread-Spectrum and Frequency-Hopping activity. Being smaller and longer range, is likely to be more of an issue than the 2.4G in or near built up areas.

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