Good day everyone and welcome back to TMac FPV-Your home for your
Journey to Better FPV Fun, Flights, and Racing Stuff! Today, we're going to
compare the performance on these four video transmitter, or VTX antennae, to find
out if one outperforms all the others and which one may be the best for your
FPV flying experience. Let's do this!
Before we get into the flight videos comparing the four different antennae, we
wanted to take a look at the manufacturer specifications for each of
these four different antennae. To begin with, three of the four antennae that
we're comparing are circularly polarized whereas the dipole of course is linear.
The size and weight specifications for each are here. One thing to keep in mind
is that you can usually get different lengths of antenna cable for the
circularly polarized antenna. The axial ratio for these two are identified of
the lollipop v2 is less than or equal to 1.4 whereas the Lumenier AXII is
approximately equal to one which is almost perfectly circularly polarized.
I contacted Actuna and they said that they did not measure the axial ratio for
their GEM antenna. The gain and standing wave ratio parameters are listed here.
The connector I chose to use for all four just to keep it consistent was the
MMCX connector because I prefer those connectors as opposed to the UFL
connectors, and of course the cost is always something to consider. The Foxeer
Lollipop V2 comes for $19.90 for two which is about ten dollars a piece
which is on par with the Actuna Gem whereas a Lumenier AXII is somewhat more
expensive. The linear dipole of course is only three to four dollars. One of the
reasons that you may want to consider using a circularly polarized antenna as
opposed to a linear dipole antenna is because you'll get better video
reception when flying near or around objects than when using the linear
dipole antenna. So, we should see that bear out in the upcoming flight videos.
The manufacturer's gain plots for both the Foxeer Lollipop V2 and Lumenier AXII
are here if you're in interested in those. As I mentioned
earlier when contacting Actuna they did not do the testing which would have
been necessary to generate the gain plot for the gem antenna so that is the
reason that it is not shown here. Here's how we went about testing these antenna
with four different flights. We tried to keep as many things as constant as
possible with the only variable being the antenna itself. So with that in mind
we used the same quadcopter which was our FlexRC Ascent X 3 inch version.
Because it's the same quad we didn't change out the video transmitter. We used
the same video transmitter which in our case was the AKK Oscars Backpack or the
OBVTX which we had set on the same power for each of the antenna and
flights and that power we used was twenty five milliwatts-and the reason we
chose twenty five milliwatts as opposed to two hundred milliwatts (which is the
other setting for the OBVTX) is we wanted to make this comparison as
difficult as possible for the antenna. So with twenty five milliwatts and the
flight path we chose, we figured that we're really going to be testing these
antenna out. We used the same frequency band and channel for all four antenna
and flights. We used the same flight pattern and we identified that with
yellow cones and/or flags. We chose to fly slo--as slow as possible--so that you
could get some sort of comparison between the different antenna as opposed
to going by so quickly. It was difficult to do but we did it as slowly as
possible! We also chose to fly low altitude with obstructions between the
pilot and the quadcopter, specifically my house, and with that we went ahead and
shut the garage door which is a metal garage door so we had a metal
obstruction between the quadcopter and the pilot when the quadcopter was flying
by the corner of the rear of the house. I kept my same pilot location I didn't
change locations from where I was controlling the quadcopter. All four
flights were conducted during the same time of day--basically when one flight
was done I disconnected the antenna, I reconnected the next antenna and I
commenced flying. The goggles that we're used for all four flights were the
Aomway Commander V1 goggles and I used the Aomway right hand circular polarized
cloverleaf antenna and the TrueRC patch antenna. So with these procedures in
place let's go ahead and take a look at the flight videos and see what we can
find out from the antenna comparison.
Okay so what, if anything, can we learn from this antenna comparison? Well, first
of all I think we've clearly demonstrated that if we're going to be
doing proximity flying, relatively low altitude, and/or through, around, or near
obstacles, structures, trees, etc it's probably a good idea to use a circularly
polarized antenna if at all possible to mitigate the effects of multipath
interference and get a better clearer fpv video. So then which of our three
circularly polarized antenna work best? Or, did any outperform all the others? I
can tell you that I was pleasantly surprised by the performance of the
Actuna GEM in our little test flight but which antenna should I put back onto my
quad? Or, more importantly for you, which antenna should YOU put on YOUR
Micro FPV Quad? Tell us what you think! Put your thoughts and remarks on this
comparison in the Comment Section below. There's going to be links to each of
these antenna for your convenience in the video description below as well. If
you found this video to be at all useful, please consider subscribing to TMac
FPV. We appreciate your time! Thanks for watching! And, as always, Happy Flying!