Controller Compairison. GL300C vs GL300A vs GL658B

I would be more than happy to send you my GL300A for testing. I was going to send it in anyway to have you mod it with connectors and buy an Evolite Kit.
Plan to mount the Amp and a pair of Omni's on my boat.

I would offer the GL658B for testing but it's on E Bay.

I just got a GL300A in (will test after Canadian thanksgiving weekend which is this weekend) and I have tested the GL658B !!

We can 100% test yours when we mod it and share the results with you !! Are you in Canada or sending it to Maxx UAV USA ?


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I just got a GL300A in (will test after Canadian thanksgiving weekend which is this weekend) and I have tested the GL658B !!

We can 100% test yours when we mod it and share the results with you !! Are you in Canada or sending it to Maxx UAV USA ?


Sent from my iPhone using PhantomPilots

U.S.A.
Sorry Kyle, Forgot you are in Canada.
 
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Remember that ANY connection that is not welded (soldered) is a loss of 0.75dBm to 1dBm. As you know, a 3dBm increase in power means the Tx power is doubled, as is any decrease of -3dBm the Tx power is cut in half.
I do not put a lot of faith is testing the Tx power through a solid connection (connecting the Rx meter to the RC by cable) since what you see is not the true RF power received by the drone. Also you can have the best and most ideal Tx RC reading BUT if the Rx in the drone is weak, all the calculations are off the table. Not to mention, is the P3/P4 equipped with an LNA (low noise amplifier) to filter out all the noise and unwanted RF in the area? What about the RC receiver (Rx) does it have an LNA? To improve Tx and Rx of any units, Rx diversity is needed and the Div Imb should not exceed 3dBm (diversity Rx is achieved by having 2 antennas capable of RF Rx and should be calibrated within 100mHz band separation). In DJI case, RC and drone have ONLY 1 Tx and 1Rx antenna which makes it a low ball RF unit.
 
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I just got a GL300A in (will test after Canadian thanksgiving weekend which is this weekend) and I have tested the GL658B !!

We can 100% test yours when we mod it and share the results with you !! Are you in Canada or sending it to Maxx UAV USA ?


Sent from my iPhone using PhantomPilots
Kyle,
I'm very interested in your theory that the same controller linked to different craft will transmit different levels of control RF signal. When you're testing,if you have time to log this data with different craft, that would be very interesting information to digest.
 
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Remember that ANY connection that is not welded (soldered) is a loss of 0.75dBm to 1dBm. As you know, a 3dBm increase in power means the Tx power is doubled, as is any decrease of -3dBm the Tx power is cut in half.
I do not put a lot of faith is testing the Tx power through a solid connection (connecting the Rx meter to the RC by cable) since what you see is not the true RF power received by the drone. Also you can have the best and most ideal Tx RC reading BUT if the Rx in the drone is weak, all the calculations are off the table. Not to mention, is the P3/P4 equipped with an LNA (low noise amplifier) to filter out all the noise and unwanted RF in the area? What about the RC receiver (Rx) does it have an LNA? To improve Tx and Rx of any units, Rx diversity is needed and the Div Imb should not exceed 3dBm (diversity Rx is achieved by having 2 antennas capable of RF Rx and should be calibrated within 100mHz band separation). In DJI case, RC and drone have ONLY 1 Tx and 1Rx antenna which makes it a low ball RF unit.


The kind of testing we can do here - absent a formal test range and an anechoic chamber - is fairly primitive and always relative and valid only under similar conditions. I have been putting some thought into this, trying to figure out exactly how to test different antenna designs and it's frustrating. And I have lots more test gear than the average UAV owner.

The likely best you can do is

1. Find an area with low background 2.4 GHz noise.
2. Use the same experimental set up all of the time.
3. Minimize use of connectors, keep cables short and symmetric
4. Do a number of tests on different days and keep good records.
5. For actual flight tests you will need low noise conditions throughout the entire test range.
6. For actual flight characteristics you will need to check ranges at different vertical and horizontal angles from the RC (beam width considerations).
7. You should also keep relative humidity fairly constant for distance tests.


So, by just stuffing a power meter on an RC you will get some broadly entertaining bits of information, but of limited utility. You really don't give the northbound end of a southbound rat about the numbers, you want to know if this configuration is better than another and under what circumstances.

The numbers I see here fall into the 'interesting, but what quite does it mean' category. About the only data that is broadly applicable are the folks looking for maximum range who run up and down the same course all of the time. Even there, subtle changes like using different RCs are probably not going to be experimentally verifiable. For a more generalized use case, beam pattern characteristics are really important. And for the general public, even factors such as size, configuration time and robustness may have more applicability than raw power.

So keep at it folks, just be careful not to get over comfortable with your data and realize that if you are actually trying to make some sense out of all this, it's pretty complicated. At the very least, doing these sorts of experiments can get you an appreciation of how hard GHz radio transmission is and how much performance DJI has managed to stuff into a cheap, small package. Yes, DJI could do a lot better and I expect the next generation of transmitter receivers will have some improvements in bandwidth rather than pure power as we're already at distance numbers that give the FAA the heebiejeebies.
 
Kyle,
I'm very interested in your theory that the same controller linked to different craft will transmit different levels of control RF signal. When you're testing,if you have time to log this data with different craft, that would be very interesting information to digest.

Hey John, I did test and the power from the inspire remotes drops down to be on par with the GL300 remotes. Now that I have the GL300A remote I'm going to see if it actually is any better than the B & C !

As far as testing, without a proper testing environment yes these are all very crude ways of testing. The reason I use the direct connection method is that I believe it leaves us with the fewest variables. I can use the same cable (internal and external) to test every remote (keeping the loss constant.




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Hey John, I did test and the power from the inspire remotes drops down to be on par with the GL300 remotes. Now that I have the GL300A remote I'm going to see if it actually is any better than the B & C !

I'll have to redo my tests. When I did my tests of GL658A versus GL300C, the Inspire produced 50% more transmit power. You can see my method here.

Which versions of GL658 did you test and compare to RC300C?
 
John,
If you still have the A can you fill in the data please?
..........

Who has the FCC # for:

Phantom 3 and 4
- GL300A >>> SS3-GL3001501 >>> Tx 0.380w
- GL300B >>> SS3-GL3001501 >>> Tx 0.380w
- GL300C >>> SS3-GL3001510 >>> Tx 0.303w

Inspire 1 and Pro 1
- GL658A >>> SS3-GL6581410 >>> Tx 0.370w
- GL658B >>> SS3-GL6581502 >>> Tx 0.483w
- GL658C >>> SS3-GL658C1504 >>>Tx 0.743w
 
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Thanks. Now we have all the data for the RC Tx power and FCC ID. Copy and save it for further references.
 
Dacon, if you ever come to Calif, Orange county that is, ping me and we'll measure the RF transmit power of your 658C and my 658A side by side, linked with a P4. I'm very curious. I'll let you know if I'm in Phoenix anytime soon, and I'll bring my meter.
 
I have an inspire gl300b but does power output really matter? Because we are just talking control signal out of the remote right? Its not like the older remotes with higher power will do anything for receiving video signal right? I use old p3 remote p4 and inspire for indoor flights and my range is about 30,000ft with any of them give or take. I never use an amp on control either ever within that range. Some guys in another group are getting 13 miles with no camera but I have to have my camera!
 
Dacon, if you ever come to Calif, Orange county that is, ping me and we'll measure the RF transmit power of your 658C and my 658A side by side, linked with a P4. I'm very curious. I'll let you know if I'm in Phoenix anytime soon, and I'll bring my meter.
Any time you want John. I have a pro ElGato spectrum analyzer for any RF testing and we can use it. You have more chances to be here than me coming to Cal.
 
Jerimiah, Standard P4 controllers are known to have weak transmit signal, losing control signal way before they should, 3000 to 4000', (ch32@4mbps) which is crappy range. Auto RTH are common with P4, but rare with P3P. With my P3P I always lose video signal first at about 10,000 to 12,000', but a always still have control of the craft to ascend and regain video. Hence some of us resort to Inspire controllers that offer better control signal, alleviating the constant auto RTH and dramatically increasing range.

My P3P (GL300A) craft has way better range and signal integrity than my P4 (GL300C) stock controller. The question is, do DJI controllers dynamically adjust the power output based on the craft they are linked to, as Kyle at Maxxuav believes. And if so, then why does the Inspire controller perform better in the real world with double the range in the exact same area?
 
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Standard P4 controllers are known to have weak transmit signal, losing control signal way before they should, 3000 to 4000', (ch32@4mbps) which is crappy range. Hence some of us resort to Inspire controllers that offer better signal.

I'm glad you're happy with your stock controller. I'm not. My P3P craft has way better range and signal integrity than my P4 with stock controller.


That's weird. I thought this first too with my new p4 using stock controller. Then I installed the p4 fpvlr antenna and would lose control within a thousand feet. Then I installed hdmi in the remote and hooked up to the omnies and the p4 defiantly has better range than any of my p3s did but nothing crazy. The output power of the video signal must be stronger than that of the p3. I cant wait to see what the mavic can do with different antennas.
 
WARNING FOR THE 32-Ch HACK.
The channels 13 - 20 are the "stock" HD (Rx) bandwidths opened from the P4 to the RC. Some of us "hacked" the Rx RC band to be able to receive channels from 21 - 32..
Except for Ch 22, ALL the upper channels are used by Sprint cell carrier for the LTE 2.5G band. Sprint is the only cell carrier in the US to use the 2.5G band for their high band LTE data. The tower radios have an Tx/P output of 16W and a radius of about 1.5 miles from tower. If you set the RC on any upper channels and are close enough to the Sprint towers, the LTE signal will drown the RF from the drone to your RC. I have good luck with Ch 22 for now, but still have problems with GO app 3.0.0. If you have any questions about the upper channels ask me, I work for Sprint.

ch.PNG
 
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WARNING FOR THE 32-Ch HACK.
The channels 13 - 20 are the "stock" HD (Rx) bandwidths opened from the P4 to the RC. Some of us "hacked" the Rx RC band to be able to receive channels from 21 - 32..
Except for Ch 22, ALL the upper channels are used by Sprint cell carrier for the LTE 2.5G band. Sprint is the only cell carrier in the US to use the 2.5G band for their high band LTE data. The tower radios have an Tx/P output of 16W and a radius of about 1.5 miles from tower. If you set the RC on any upper channels and are close enough to the Sprint towers, the LTE signal will drown the RF from the drone to your RC. I have good luck with Ch 22 for now, but still have problems with GO app 3.0.0. If you have any questions about the upper channels ask me, I work for Sprint.

View attachment 66992


Cool that explains if I use channel 32 I can go about 2000 ft. Channel 21 sky is the limit here. Well the battery to be exact.
 
That's weird. I thought this first too with my new p4 using stock controller. Then I installed the p4 fpvlr antenna and would lose control within a thousand feet. Then I installed hdmi in the remote and hooked up to the omnies and the p4 defiantly has better range than any of my p3s did but nothing crazy. The output power of the video signal must be stronger than that of the p3. I cant wait to see what the mavic can do with different antennas.
You're not comparing apples to apples. Your omnies have better performance than stock antennas. Aren't you using amps also? The GL300C controller IMO is a weakling. Everyone has to modify it to get decent performance.
 
You're not comparing apples to apples. Your omnies have better performance than stock antennas. Aren't you using amps also? The GL300C controller IMO is a weakling. Everyone has to modify it to get decent performance.

Yeah just amps on the video only. My last controller was a c for the matrice and got 9 miles with it. It fell apart so my new one is a b and it gets me the same distance. But you are right its not apples to apples. With the right antennas I have found all remotes to be good. I really want to see if the mavic shows an advantage on the indoor system if I can mod the remote.
 

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