as goggles and sometimes the glare on the screen can be a
real problem. The displays also are small enough that you
can pack a couple of extras to give to observers if they want
to watch you fly (Figure 3).
The alterative display type is a pair of FPV goggles. This
is really like playing a virtual reality video game, except that
it isn’t virtual. You really feel like you are riding along on
the quad. There are goggles with advanced features that
help move your camera gimbal by simply tilting your head.
Some even have fans to keep the air inside cool and fresh.
The goggles in our starter kit (Figure 4) are standard
definition with a few bells and whistles, but plenty to
decide if the goggle experience is the way you want to fly.
Antennas are an often overlooked part of many
systems. While RF engineering seems like (and mostly is
some would argue) a form of magic, it is important. A
good camera, transmitter, receiver, and monitor can be
rendered useless by a poor choice of antenna.
The classic whip or
“rubber ducky” antenna is
what we are used to
seeing on our handheld
radios, walkie-talkies, and
many remote control
transmitters. Sadly, these
inexpensive antennas are
not the best for FPV work.
These simple designs are
sensitive to the orientation
of the transmitter and
receiver; they work best
when the transmitting and
receiving antenna are in
the same orientation.
Given that our quad’s
orientation is changing and
the mounting constraints
may be difficult, this is
generally not the ideal
The patch or helical
antenna is a very long
range design, but also very directional. Given the
requirements that your aircraft remain in line-of-sight,
these designs are unnecessary and impose the extra
complication of needing the receiving antenna to
track the vehicle — either manually or automatically.
A circularly polarized antenna such as a clover
leaf design is the most popular choice. Such
antennas can be easily built or purchased, are
compact, and are relatively insensitive to the
orientation of the transmitter and receiver.
You can run your FPV camera and transmitter
from the main flight battery. In fact, many setups are
capable of running off the balanced charge lead of your
battery, including our kit. For the first several flights, I did
this with no problems. Sure, there is some extra drain from
the load of the transmitter, but I generally fly with giant
batteries anyway, so it wasn’t a concern. I did notice some
noise on the video signal though.
After some research, I found out that it could be from
the large and rapidly changing current demands on the
main battery. I could put some kind of power filter in, but
instead decided that it really wasn’t worth the trouble. I
added a second and much smaller battery to power just the
FPV gear. I chose a Turnigy 1,000 mAh 2S 20C LiPo Pack,
but any 500-1,000 mAh battery should do (Figure 5).
Another possible addition to your FPV system is an on-screen display or overlay. This is similar to the heads-up
displays in commercial and military aircraft. At a glance and
through your line-of-sight, critical information such as
50 SERVO 02.2017
Figure 5: Having a small
battery for the FPV system
seemed to make sense, as I
would prefer to keep the
safety-critical flight systems
isolated from the toys like
cameras and other
Figure 3: The “TV” type display
screen has a collapsible sun
shield. When folded flat, it is
easy to stick a couple of these
into your flight bag for onlookers
or other crew members to use.
The integrated battery, charger,
and radio receiver make it very
Figure 4: The Fat Shark goggles are compact and easy to use. The volume
and channel selection buttons are raised and easy to find with the headset
on. The center button can be used to activate the head tracker mode.