made some RF discoveries today

[jsposito]

Only the P4P and Inspire 2 adds the 5.8 option. It has the advantage of moving your control and video downlink outside of the heavily used 2.4G wifi bands. But if you're using the channel hack, you're already able to get outside of the wifi bands. So that's less of an issue.

Another advantage is the channel width in the 5.8G band is twice as wide (20Mhz), meaning your higher bit rates (10Mbps) will work better.

A further advantage of 5.8 is reduced loss due to moisture (breaks thru foliage better, and a lower fresnel zone and better scattering (gets around objects better). One drawback is that 5.8 has more loss thru the air, so it doesn't carry as far, but if more gain is added this is easily overcome.

Thank you
"But if you're using the channel hack, you're already able to get outside of the wifi bands. So that's less of an issue. "

Is that because of channel 20 on 5.8 ?

 

[GadgetGuy]

So, we have the 5.8 option on the P4& P4P . What advantage if any is there over 2.8? ( I realize this is beyond the scope of your research). Thanks

No 5.8Ghz option on the P4. Only on the P4P.

 

[GadgetGuy]

While I haven't been able to test the vswr of the stock antennas (they get destroyed during the mod), but I know they are actually not a simple omni. They are a 3.5dBi directed omni, so they add gain, which brings the 16dBm output of the RC up to 19.5dBm in the US.

I would imagine they are a bit wider of a match over the 2.4 range than the 6dBi I have. So I would think the antennas themselves probably work fine over the whole 32 ch range. That being said, I think my first video makes it clear that ch 20-22 are the preferable options for stock.

21 for the win! (Unless Jeremiah is nearby....!)

 

[james_hunt]

Thank you
"But if you're using the channel hack, you're already able to get outside of the wifi bands. So that's less of an issue. "

Is that because of channel 20 on 5.8 ?

The channel hack is only for the 2.4Ghz Band. If you don't use the channel hack, you're stuck to ch.13-20, all of which are already occupied by wifi devices. Using the hack enables more channels in the 2.4Ghz Band, outside of the wifi range.

5.8Ghz is a completely different topic.

 

[jsposito]

No 5.8Ghz option on the P4. Only on the P4P.

yes sorry, I meant P4 PRO

 

[GadgetGuy]

yes sorry, I meant P4 PRO

In that case, the results from using Auto 5.8Ghz on the P4P are vastly superior to using 2.4Ghz on any channel in hightly urban areas, and the benefit of 2.4Ghz will only be realized in CE areas (more power in CE) and those needing to penetrate nearby trees, and then only with a boosted 2.4Ghz transmitter mod.

 

[jsposito]

In that case, the results from using Auto 5.8Ghz on the P4P are vastly superior to using 2.4Ghz on any channel in hightly urban areas, and the benefit of 2.4Ghz will only be realized in CE areas (more power in CE) and those needing to penetrate nearby trees, and then only with a boosted 2.4Ghz transmitter mod.

No doubt after a truly boosted mod for distance I'd imagine it would be for naught without a battery mod. I think that would have to follow.

 

[GadgetGuy]

No doubt after a truly boosted mod for distance I'd imagine it would be for naught without a battery mod. I think that would have to follow.

Absolutely, which is why I haven't tried to increase the 4+ mile stock P4P range. With a 24 minute max flight time currently, that's good enough. The 1 pound lighter stock RC setup, and no external batteries to fool with is a real treat, after the P4 and P3P which required both to get the same results!
Battery mod runs $250 from Paul at FPVCustoms.com

 

[jsposito]

Check this out - for the first time i put the parabolics on backwards, and didnt realzie, even with that I got 10,000 feet BUT had 4 aircraft disconnects and 3 weak image warnings!

 

[GadgetGuy]

Check this out - for the first time i put the parabolics on backwards, and didnt realzie, even with that I got 10,000 feet BUT had 4 aircraft disconnects and 3 weak image warnings!

If you weren't paying attention to your directionality, that could easily happen. However, you would likely have been facing away from the aircraft with your body blocking the signal, or, if you were pointed at the aircraft the whole time, your body itself was reflecting the directional signal back to the aircraft around the refelector, just not as well as the parabolic reflector was reflecting it at your body!

 

[John Locke]

Check this out - for the first time i put the parabolics on backwards, and didnt realzie, even with that I got 10,000 feet BUT had 4 aircraft disconnects and 3 weak image warnings!

Whoa, that's certainly not helpful to the body, using a parabolic reflector to concentrate 2.4Ghz microwaves directly at your body. As long as you didn't have a 600W amplifier on the antenna, I guess you're OK.

 

[GadgetGuy]

Whoa, that's certainly not helpful to the body, using a parabolic reflector to concentrate 2.4Ghz microwaves directly at your body. As long as you didn't have a 600W amplifier on the antenna, I guess you're OK.

Have him make a note in his medical file so when he develops cancer in 5 years that all we know why! If the RC can fry itself when powered without any antenna attached, imagine what it can do when it cooks human flesh for 25 minutes!

 

[jsposito]

If you weren't paying attention to your directionality, that could easily happen. However, you would likely have been facing away from the aircraft with your body blocking the signal, or, if you were pointed at the aircraft the whole time, your body itself was reflecting the directional signal back to the aircraft around the refelector, just not as well as the parabolic reflector was reflecting it at your body!

wow, lol okay.

Have him make a note in his medical file so when he develops cancer in 5 years that all we know why! If the RC can fry itself when powered without any antenna attached, imagine what it can do when it cooks human flesh for 25 minutes!

hahaha..lol! seriously sad but true........and funny. First time I've laughed since I had to send my girl to dji.

Thx all..

 

[jsposito]

Whoa, that's certainly not helpful to the body, using a parabolic reflector to concentrate 2.4Ghz microwaves directly at your body. As long as you didn't have a 600W amplifier on the antenna, I guess you're OK.

I hope so! - with time on my hands I decided to go back to the gym so I want to be healthy. : )

 

[The Flying Swan]

Thanks for your hard work James - very informative. Can I ask a question. I have a P4 with a boosted MaxxRange antenna, as well as the Evo Lite. MaxxUAV recommends leaving the setup in auto. I'm wondering why that is and if that logic stands up to your findings? You mentioned in your video the sweet spot was quite narrow? Is it worth unlocking the extra channels if there is so little wiggle room for adjustments?

 

[GadgetGuy]

Thanks for your hard work James - very informative. Can I ask a question. I have a P4 with a boosted MaxxRange antenna, as well as the Evo Lite. MaxxUAV recommends leaving the setup in auto. I'm wondering why that is and if that logic stands up to your findings? You mentioned in your video the sweet spot was quite narrow? Is it worth unlocking the extra channels if there is so little wiggle room for adjustments?

Always good to have options to experiment with! Try using one of the manual channels in the hack in the areas you normally currently fly in Auto and see. The results will speak for themselves! Vary the manual channel you select to fine tune it. Nothing like boots on the ground, rather just than lab simulations, which have their place, too!

 

[GadgetGuy]

wow, lol okay.



hahaha..lol! seriously sad but true........and funny. First time I've laughed since I had to send my girl to dji.

Thx all..

You have to maintain your sense of humor while dodging bullets and hidden minefields! They are everywhere!

 

[The Flying Swan]

Always good to have options to experiment with! Try using one of the manual channels in the hack in the areas you normally currently fly in Auto and see. The results will speak for themselves! Vary the manual channel you select to fine tune it. Nothing like boots on the ground, rather just than lab simulations, which have their place, too!

I agree the field is a great place to figure these things out. I'm just wondering if there is a scientific reason why Maxx suggests leaving it in auto. Is it simply that fine tuning the expanded channels COULD cause more harm than good if not done properly and therefore is just makes good sense from a business perspective to recommend a set and forget method?

 

[GadgetGuy]

I agree the field is a great place to figure these things out. I'm just wondering if there is a scientific reason why Maxx suggests leaving it in auto. Is it simply that fine tuning the expanded channels COULD cause more harm than good if not done properly and therefore is just makes good sense from a business perspective to recommend a set and forget method?

Correct! It's a liability and marketing issue, not a scientific one. Recommending a hack to use their device is not something any reputable company would do. First, misuse of the hack could cause serious problems with performance which could lead to a crash, and there is no assurance the hack will still work going forward, and anyone relying upon the hack for performance could potentially demand a refund from the company that sold them a device depending upon the hack. The hack could be crippled by DJI at any time. The first question after every update is does the 32 channel hack still work. If their equipment works with Auto, the performance will be good enough, even if not the very best, which only a channel hack can tweak.

 

[John Locke]

I agree the field is a great place to figure these things out. I'm just wondering if there is a scientific reason why Maxx suggests leaving it in auto. Is it simply that fine tuning the expanded channels COULD cause more harm than good if not done properly and therefore is just makes good sense from a business perspective to recommend a set and forget method?

The problem with auto is you cannot dictate the "Transmission Quality". If it's at 10mbps the distance is affected, versus 4mbps the range is better. After many months of trial and error I prefer using the hack on channel 30, 31, or 32 with the transmission quality set to 4mbps. This consistently gets me out past 2 miles in most any area, as long as it's not downtown LA. If you're flying short range with goggles in a more rural area, you may want to try auto to increase display clarity a little bit. In rural areas auto works good on the standard channel, just realize Auto will not select from any of the HACK channels. To get away form normal wifi frequencies in town you need to manually select the lower 30's channels, to get peace and quiet, along with maximized range.

Try these things and see for yourself. Use a windsurfer too, they do help. However, with P4 the best range is achieved (for non boosted setups) using an Inspire controller (GL658), that's what I use. GL300C is a bit weak, based on my RF testing.