SMA-RP connector conversion

[Roamer105]

I received the antenna conversion kit Long-Range Extended Antenna Booster Signal Amplifer For DJI Phantom 3 Pro&Ad Whi and installed it on my P3P remote control without any problems. The patch antennae that come with the kit are only a little bit better than the originals due to an increased directional characteristic. The beauty of this conversion is that it is completely reversible since no holes are drilled etc. Furthermore, I ordered two sets of high quality antennae that I can simply chose to attach as needed. One set is made by L-com (HG2409RD-RSP), a high performance (9db gain) omni-directional antenna set and the second set is made by Alpha (APA-M25) which is a higher quality directional antenna with 8db gain at a beam width of 60 degrees.

So, if I play with VR goggles or an Autopilot follow-me, I use the omni-directional antennae since I don't really know which way I am pointing relative to the quad. If I run a long distance waypoint mission, I'll use the Alpha antennae.

 

[alokbhargava]

Give us the performance results for Omni directional antenna.

 

[Roamer105]

As soon as I get the in (later this week)....


Sent from my iPad using PhantomPilots mobile app

 

[Roamer105]

As soon as I get the in (later this week)....


Sent from my iPad using PhantomPilots mobile app

OK. Got both sets of antennae in my hands now. I repeated my tests (they involve both, distance and penetration/obstructions such as trees and hills). They are setup by keeping the P3P stationary on a tree trunk about 2 feet of the ground, but encumbered by trees in most directions and the RC mobile (hop in my car and drive to various places where I tested other setups such as original antennae with and without windsurfers.

I found that the ALPHA (APA-M25) directional antennae work quite a bit better than the ones that came with the kit. The directional cone appears to match what the manufacturer's specifications indicate. Clearly, they are very useful to get significant distance as long as you can keep them close to vertical and within about 20 degrees (+/-) or less of actual direction. I found that the ALPHA were much better in "penetrating" through obstructions such as trees but only at distances less than 2 miles. I maintained good signal within and beyond points where neither the original (with and without windsurfers) or the little patch antennae received in the kit worked.

The L-Com omni-directional antennae with 9db gain clearly punch through a lot within short distances (less than 1/4 mile). I did get a workable signal up to about 2 miles at which point the antennae appear to work better (vertical, but aligned sideways to the direction to the drone - a bit counter-intuitive). I do feel pretty good with these even with lots of interference in distances up to 1 mile. Their performance is about comparable (but not as directional) to the originals with windsurfers.

BTW: Check my simple iPad stand stability enhancement. Just add a washer and tighten well. Works like a charm!

 

[Prowler]

How do that L-com compare to a TP-Link 8dbi ?

 

[Roamer105]

I want to add an update to my previous post regarding the SMA-RP conversion using the OEM antenna holes.

While the conversion was quite easy and the post conversion use of my two antenna sets worked out fine for some time, I noticed that it was next to impossible to maintain the SMA-RP connector tightness in the OEM hole because there is no good surface for the nut/washer to be tightened on. It is inevitable that occasionally one ends up rotating that connector while attaching or removing an antenna. The consequence: the connector cable eventually gets sheared off. Needless to say - bad or no communication.

So, the lesson learned: Don't use those holes unless you are willing to hard-glue the connector shaft or add some other form of nut-lock gizmo on the inside to absolutely prevent rotation.
During my learning experience, I sheared off one of the connector cables and damaged the other. As a consequence, I purchased two 6" cables (1 LONG THREAD RP-SMA Female to MMCX Male Right Angle RG316DS Pigtail 4-20 INCH) with long-thread connectors. There is no need for long threads, standard is just fine. Now, I did end up drilling two holes on the top ans close as possible to the OEM antenna position, installed the cables (very high quality I must say - thicker cable) and attached two SMA-RP elbows. Now, I am back in business with a more solid setup and probably a little better performance than before (shorter, lower loss cables) - but permanent modification (holes).

 

[RocketBrew]

I noticed that it was next to impossible to maintain the SMA-RP connector tightness in the OEM hole because there is no good surface for the nut/washer to be tightened on.

Did your kit come with the two inserts as shown in the eBay photo?

I just installed the "clean install" cable kit from @JakeMaxxUAV, which looks like the same set without the antennas included.
It did not include those pieces, and I noticed the same issue with the nut not being able to tighten properly due to the gap.

 

[Roamer105]

Did your kit come with the two inserts as shown in the eBay photo?
View attachment 52962
I just installed the "clean install" cable kit from @JakeMaxxUAV, which looks like the same set without the antennas included.
It did not include those pieces, and I noticed the same issue with the nut not being able to tighten properly due to the gap.

I don't think it did. I certainly did not see anything at the time when I did the conversion nor can I find it now (I kept all of it).