Specifications

Extending the Range with an External Antenna
The PT2272 RF module has a built-in PC loop antenna with a range of around 30’. For most
purposes, this range works just fine; you’ll probably stop hearing the buzzer before you run out
of range.
However, if you’re using it in a carbon fiber (CF) rocket, you may not get the range you want,
since CF is conductive and attenuates radio signals. If you find that you can’t get it to work
inside your CF AV bay, you may want to install an additional antenna.
There are two types of antennas that you can make that will work. The first is a simple wire
whip antenna, basically you simply cut a 9 3/8” piece of 24 gage solid insulated hookup wire
and solder one end to the antenna input (which is the empty round pad marked “ANT” on the
corner of the RF module right next to the red “ON” LED). This works OK, but you’ll need to
find a way to keep the wire from kinking or otherwise distorting or it won’t be as effective.
Depending on the layout of your AV bay and the size of the rocket, this may be easy, or it may
be dang near impossible.
The other type of antenna, and the one that we recommend, is a helical antenna. Take the same
9 3/8” piece of 24 ga. solid wire and wrap it around a round form about ¼” in diameter,
spacing the coils one wire-width apart. A piece of 3/16” paper launch lug works very well for
this. Solder one end to the aforementioned antenna input on the RF module, and secure the
antenna so it can’t move around. A little paper masking tape works fine, and it’s OK if you
leave the launch lug in the middle to help keep the coils in position. You can almost always
find a place to mount the helical antenna, since it uses up a whole lot less room than a wire
whip antenna.