RF power measurements

AnchorageAk · Feb 28, 2017

Testman said:
30/40 metres.

That's impressive.

Testman · Feb 28, 2017

[Quote = "AnchorageAk, posta: 1115409, membro: 75.705"]. Questo è impressionante [/ quote]
I have this range after i bought a RC GL300A, with original Phantom 4 RC GL300C i have loss of radio and video signal at 12000 feet with windsurfer and the signal was often instable a few of distance of me.

John Locke · Feb 28, 2017

AnchorageAk said:
John,

I was unable to update the Inspire controller with the P4. Where you every able to update it? I always got the message"up date available". But, it would not up date it.

What model Inspire RC do you have?

You should update the controller separately, after the craft firmware is updated. Or update the craft to the latest firmware with digital assistant using a PC. Update the RC with the craft turned off. If this process doesn't work, report back with the version firmware in the RC.

JohnnyB · Mar 3, 2017

Mr. Locke, got my GL658C. Linking went great with the P4. It came with firmware version 1.6.0. Everything works well with this. I see that version 1.7.60 is available. Should I just leave it alone since all is well or update?

John Locke · Mar 3, 2017

If it links ok you might want to leave it alone if the craft has matching firmware for the 1.6 in the RC. I'm not sure what version of craft firmware is a match, but maybe someone in the forum keeps track of that. The alternative is to load the latest firmware in the craft and RC to insure they are matched pair firmwares. I'm running the 1.6 package firmware, but the version that shows in my "ABOUT" section does not say 1.6 for both craft and RC. It shows what I list in my signature.

Andy Middleton · Mar 31, 2017

Has anyone outside of an FCC area done any power checks on the various RC controllers when they are set to the lower limits for Europe. Most info I have found refers to controllers running the higher FCC power limits.

John Locke · Mar 31, 2017

Andy Middleton said:
Has anyone outside of an FCC area done any power checks on the various RC controllers when they are set to the lower limits for Europe. Most info I have found refers to controllers running the higher FCC power limits.

Good question!
I think this forum should crowd fund me to fly to the UK to do this work. I seriously think it needs to be done this summer.

N017RW · Mar 31, 2017

In the mean time...
How do the FCC regulated units compare to spec?

Similar could be expected of CE?

Is the CE compliance testing data searchable?
Is it 'officially' implied or derived from FCC data.

The US protocol has such credibility in some matters that it wouldn't surprise me.

John Locke · Apr 1, 2017

N017RW said:
In the mean time...
How do the FCC regulated units compare to spec?

Similar could be expected of CE?

Is the CE compliance testing data searchable?
Is it 'officially' implied or derived from FCC data.

The US protocol has such credibility in some matters that it wouldn't surprise me.

The comparison of CE version versus FCC version is in the DJI spec

You can also search on the FCC# printed on the back of your controller here to find the specs at the bottom of the page it takes you to.

N017RW · Apr 1, 2017

Yes I'm aware of the FCC website containing the third-party test data. I have referenced it here for years.
Thank you.

JohnnyB · Apr 1, 2017

Speaking of, I'm in US and I tested my RC the other day. Reading was 11dBm coming straight out remote.. with antenna and connection loss, 17.. how do I fix this?
(GL300C)

N017RW · Apr 1, 2017

What equipment are you using to measure conducted power?

JohnnyB · Apr 1, 2017

Well I could only afford the immersion rf meter so it's the only choice I have. It measured just under 12mW hooked straight to RC.

N017RW · Apr 1, 2017

mW or dBm?
You've mentioned both.

What attenuation do you have in-line?

JohnnyB · Apr 1, 2017

12mW converted to 10.79dBm. I was also measuring RC with 3W sunhan attached so I used 40dB of attenuators, (only having a 30dB and 10dB) even when measuring RC only, trying to get best accuracy.

N017RW · Apr 1, 2017

You have to add the in-line attenuation to the measured value.

JohnnyB · Apr 1, 2017

Yes sir.. I set attenuation value in the meter and it does that math after measurement itself.

Andy Middleton · Apr 1, 2017

Being a digital 2 way signal I believe the output will not be a constant 100% duty cycle possibly 50% at most so probably why the immersion meter is reading the lower values due to the signal switching on and off. I may be totally wrong but this is what I think may be happening.