5.8 vs 2.4 distance

[GadgetGuy]

You can still select automatic channels even if you're using the 32 channel hack... Unless I'm misinterpreting your comment.

If you select Auto, it will cannot use the extra channels. It bypasses all of them. That's been a known limitation since day 1 of the channel hack among those who use it properly, which is also widely misunderstood by those first trying it. You must select a manual channel from among the additional channels to get any benefit from the 32 channel hack.

 

[james_hunt]

This is true and easily observed on the audio spectrum as well. However for any given radio signal this is a good rule of thumb.

 

[GadgetGuy]

As has been discussed before, in fact even earlier in this very thread, the 2 dBm higher RF output on 5.8 GHz helps but it is not a very significant factor, in fact additional path loss on 5.8 GHz (maybe 6-8 dB at a couple of miles) more than negates the slight power advantage. If 5.8 is superior in a given situation it is due almost exclusively to a lower noise environment.

No argument, but every little bit helps. All I truly care about is that Auto 5.8GHz just works, for everyone who has tried it in heavily urban environments, out to 4+ miles at 100 feet AGL in every direction, with clear LOS! If it works there, it will work anywhere with clear LOS, which I have also confirmed. I'll leave the nitty gritty details of why to the more knowledgeable EE guys like you! Anyone who is having range issues in urban areas, and hasn't yet tried Auto 5.8Ghz on FCC, is missing out. If your issue is tree penetration, you'll need a 2.4Ghz antenna mod and boosters, as 5.8Ghz does not penetrate obstacles as well, and we have no effective 5.8Ghz antenna mod yet, so best to use those already available for 2.4Ghz.

 

[james_hunt]

Yes sorry I mean the 32 channel hack. I've see you have good luck on 5.8 but I run the L coms on channel 21 on 2.4 The flight was also a heavy urban area with a population of about 50,000. I've never used the stock transmitter. I've got an extra set of L-coms with magnetic bases if anyone wants them.

Interested in your L-coms... I'll PM you.

 

[N017RW]

Higher freg means poorer propagation and range. That's physics.
Attenuation is only one component and while it is low, 5.8 is more attenuated compared to 2.4.
5.8 has lower FCC power limits than 2.8 further exacerbating my first sentence.
5.8 is less crowded (for now) so that is the reason for what many are experiencing.
Again it doesn't change the physics associated with higher frequencies in general thus my ROT comment.

 

[GadgetGuy]

Higher freg means poorer propagation and range. That's physics.
Attenuation is only one component and while it is low, 5.8 is more attenuated compared to 2.4.
5.8 has lower FCC power limits than 2.8 further exacerbating my first sentence.
5.8 is less crowded (for now) so that is the reason for what many are experiencing.
Again it doesn't change the physics associated with higher frequencies in general thus my ROT comment.

Theory and Rules Of Thumb are one thing.
Real world results are what truly matter.
DJI has knocked it out of the park with their P4P Auto 5.8GHz setting.
Best stock range yet of any Phantom!

 

[N017RW]

No argument there.
Understanding the reasons goes beyond emotion.
It's a matter of spectral congestion not any 'special sauce' from or by DJI.

 

[james_hunt]

Higher freg means poorer propagation and range. That's physics.
Attenuation is only one component and while it is low, 5.8 is more attenuated compared to 2.4.
5.8 has lower FCC power limits than 2.8 further exacerbating my first sentence.
5.8 is less crowded (for now) so that is the reason for what many are experiencing.
Again it doesn't change the physics associated with higher frequencies in general thus my ROT comment.

Actually the FCC limits in the US are the same for 2.4 and 5.8 Bands. +36dBm/4W.

 

[N017RW]

TX power is limited to 1 watt.
You're quoting ERP which accounts for antenna gain.
Gain increases directivity by limiting beam width. This introduces other compromises.
5.8 allows more radiator gain due the aforementioned issues with propagation.

 

[GadgetGuy]

No argument there.
Understanding the reasons goes beyond emotion.
It's a matter of spectral congestion not any 'special sauce' from or by DJI.

Indeed, although emotion doesn't impact or alter the results. It just makes for a happy customer! No matter the reason behind the results (and I don't dispute your analysis), DJI is the first to finally deliver on their long range promises. Too bad they waited so long to recognize and work around the spectral congestion. However, "special sauce" or not, DJI now has the long range urban solution and is finally fulfilling marketing promises!

 

[GadgetGuy]

TX power is limited to 1 watt.
You're quoting ERP which accounts for antenna gain.
Gain increases directivity by limiting beam width. This introduces other compromises.
5.8 allows more radiator gain due the aforementioned issues with propagation.

Auto 5.8 for the win!

 

[Capo]

View attachment 82108

Wow, that graphic explains a lot. 5.8GHz works throughout my house, but is not present outside at all. I have block exterior walls and stone/brick facing outside, but see no 5.8GHz outside at all. I also find my range is not much different outside in a rural area whether I use 2.4 or 5.8GHz.

 

[Spike_151]

TX power is limited to 1 watt.
You're quoting ERP which accounts for antenna gain.
Gain increases directivity by limiting beam width. This introduces other compromises.
5.8 allows more radiator gain due the aforementioned issues with propagation.

Apart from when you fit a conquer range extender with twin 3 watt amplifiers like mine ; )

 

[VVATC]

I assume you mean the P4P, as the P4 has no 5.8Ghz option. You have to press on the blue 5.8 to see the option to change to 2.4 and vice versa. Then, you should be able to either select Auto, or a manual channel.

I thought that was the case. Reading the manual is doesn't show a 2.4 option, but I was watching a youtube video on how to change the frequencies. The video said it was for the P4 but it must have been for the P4P. Thanks...

 

[GadgetGuy]

I thought that was the case. Reading the manual is doesn't show a 2.4 option, but I was watching a youtube video on how to change the frequencies. The video said it was for the P4 but it must have been for the P4P. Thanks...

Yes, lots of new P4P owners never owned a P4 to know there was (and still is) a P4 before there ever was a P4P, and so they make no distinction, or get careless with the Professional "P" part. We know better!

 

[shockwave199]

I haven't ever had a problem with my P3 and 2.4 in all kinds of different areas. I'm not particularly interested in needing 5.8 now, so I may go with a p4a.

 

[RonHarper]

No argument there.
Understanding the reasons goes beyond emotion.
It's a matter of spectral congestion not any 'special sauce' from or by DJI.

If there isn't any "special sauce" why hasn't any other single drone company managed to come even close with range?

 

[RonHarper]

Auto 5.8 for the double win! Truly over 4 miles STOCK in urban environments. No need for giant things like the Titan Conquer which can't even run on 5.8 anyway. And using boosters actually increases noise as well.

 

[N017RW]

If there isn't any "special sauce" why hasn't any other single drone company managed to come even close with range?

Spectral density (the same reason the '32 channel hack' worked) and utilizing IEEE 802.11n

 

[Capo]

Spectral density (the same reason the '32 channel hack' worked) and utilizing IEEE 802.11n

Lightbridge doesn't use Wi-Fi protocols (such as 802.11n), even though it uses the same frequencies. Too much overhead. Lightbridge uses a connectionless protocol not unlike UDP. That means that it transmits packets without the overhead of verification. This reduces latency. It's also a digital protocol as compared to many analogue protocols used by other controllers/FPV. It is definitely a proprietary (special sauce) protocol.