Antenna Booster Analysis

[GadgetGuy]

That is exactly how I have looked at it. I am a former electronic tech and graduated from an electronic engineering trade school many years ago. I usually don't try to reinvent the wheel. though, so I have been doing what everyone else has. It just seems everyone is amplifying the input side of video signal at the remote, probably for convenience. Without surprise that is the one that seems to drop while the amped control signal is still good. But, once you lose video and telemetry back, you are disconnected no matter how many bars your control signal had. I need to choose the right size amp for video/telemetry back to the remote. I was thinking of one of the little 2.4ghz ones they sell on Hobby King.

My P3P solution was to stick to the W323 old motor P3P which had the highest video power output of any P3P version at .746 watts. The P4 has 20% less video power output than that, and 20% less control power from the GL300 v. the W323 P3P GL300A controller.

However, you are not "disconnected" once you lose video and telemetry back, as long as you still have the green LED light on the transmitter. If you do, you still have full control of the aircraft with the transmitter, even without the app. You can initiate RTH, you can elevate, you can rotate, you can keep flying and pushing through the interference, and see if FPV comes back. Usually, only the FPV is lost and you retain telemetry. Once the green LED turns to red, you have lost all control, and your "Loss of Signal" settings take over, which is usually RTH, unless you changed it to Hover or Land.

 

[dirtbird]

This has been an interesting read. Can anyone recommend a good source for purchasing quality Windsurfers. They seem to come in all kinds of flavors. The best I can gather the two-piece system is best for fitting in to bags. It doesn't really matter whether the material is copper or foil and above all the surface needs to be smooth.

The general size of the windsurfer does have me wondering though. Some seem to cover only half the antenna and others seem to cover all of the antenna. Wouldn't it make more sense to cover the antenna entirely?

 

[GadgetGuy]

You can even make your own out of aluminum foil covered cardboard cutouts. They all do the same thing. Full coverage is slightly better. V shaped are best which extend beyond the front of the antenna, but none match actual amplification with a replacement spherically polarized antenna.

 

[JonEQuest]

My P3P solution was to stick to the W323 old motor P3P which had the highest video power output of any P3P version at .746 watts. The P4 has 20% less video power output than that, and 20% less control power from the GL300 v. the W323 P3P GL300A controller.

However, you are not "disconnected" once you lose video and telemetry back, as long as you still have the green LED light on the transmitter. If you do, you still have full control of the aircraft with the transmitter, even without the app. You can initiate RTH, you can elevate, you can rotate, you can keep flying and pushing through the interference, and see if FPV comes back. Usually, only the FPV is lost and you retain telemetry. Once the green LED turns to red, you have lost all control, and your "Loss of Signal" settings take over, which is usually RTH, unless you changed it to Hover or Land.

I got lucky and bought a 300A remote controller from Craigslist recently for $80. I plan to eventually use that as my stock backup controller since it is naturally more powerful. I am going to amp the 300B one since I already drilled it and once boosted the small power difference shouldn't matter too much. I do have the newer style bird though.

 

[GadgetGuy]

I got lucky and bought a 300A remote controller from Craigslist recently for $80. I plan to eventually use that as my stock backup controller since it is naturally more powerful. I am going to amp the 300B one since I already drilled it and once boosted the small power difference shouldn't matter too much. I do have the newer style bird though.

The GL300B has the same power as the GL300A. The new W323A and W323B motor birds have 18%-30% less video power from the aircraft, so I lose FPV stability on them at 3-4 miles instead of 4-5 miles, but they offer 10% longer flight times. Too bad you can't have the best of both on one bird!

 

[JonEQuest]

The GL300B has the same power as the GL300A. The new W323A and W323B motor birds have 18%-30% less video power from the aircraft, so I lose FPV stability on them at 3-4 miles instead of 4-5 miles, but they offer 10% longer flight times. Too bad you can't have the best of both on one bird!

I didn't know that. I thought the A was more powerful than the B, and the B was more than the C. At least I have the 2 best controllers. One with the Davinci chip.
I do have the W323A bird so I guess if I boost that I will be in good shape with longer flight times and the better range. The best price seems to be on HobbyKIngs website.
2.4GHz 2 Watt Signal Amplifier for DJI Phantom 1 & 2 (White)

 

[Controls Weenie]

I think it was RFGuy that said the p3p antenna has vertical polarity. I though vertical antennas were for applications were signals were bounced off of objects and return back like a radar. Why would a one-way transmission use vertical.? The vertical pattern actually transmits less power than omni directional.

 

[Mark The Droner]

I think you need to do some reading regarding polarity.

You might also ask yourself why DJI uses nothing but vertical polarity.

 

[JonEQuest]

OK, I will bite, why is that?

 

[Mark The Droner]

I was responding to the comment above: The vertical pattern actually transmits less power than omni directional.

Note that his sentence is made as a statement of fact. It's not a question or a theory that he has. There is not much point in getting into a discussion until somebody does some research so he knows at least somewhat of what he's talking about.

I suggest you read about omni antennas and then read about directional antennas. Think about the advantages and disadvantages.

Next, read about linear (as in vertical / horizontal) polarity and then read about circular polarity. Think about the advantages and disadvantages.

 

[N017RW]

The vertical pattern actually transmits less power than omni directional.

Hogwash.

You're conflating terms.

 

[henick]

Maybe by less he only understands the smaller focus (spotlight) and misunderstands the idea of the added necessity to be accurate enough to fully realize the entire range of a smaller sized spotlight vs the omni directional (floodlight) approach. The point of the 'spotlight' being to reduce signal decay at a distance. Photons. Light is a good example to illustrate.

 

[philjmj]

Excellent info. Thanks.