1.3 GHz Ground Station Initial Setup

2/15/18: See updated schematic here.

Today I mounted all the equipment onto the back of the Crosshair antenna. My plan is to use the Crosshair as the base, because it attaches directly to the tripod. With all the gear attached to the back of the Crosshair on the tripod, it is easy to make setup changes, such as changing the video receiver antennas.

The idea is that if I am flying far, I'll manually aim the Crosshair (the tripod) in the direction of the flight, and swap back to the Airblade for flying around in closer.

This is what is wired up on the back of the tripod now.

The Setup without the Battery

With the Battery

Mounted on the Tripod

Front View

New 1.3 GHz Video Antennas

I received my omni-directional antennas for the Sabre and for the ground station. I got a pair of the IBcrazy Airblades, as well as a TrueRC Singularity. The Airblades are both for the receiving end, as well as the video transmitting side (on the plane). The Singularity is to try in place of the Airblade on the plane, because it has a much smaller form.

The pair of Airblades

Singularity (Left), vs. Airblade (Right)

Ground Station Progress & Updated Schematics

I made some minimal progress on my ground station. I got a tripod to mount things to as well as the 1.3 GHz Crosshair video receiver antenna.

Those are both shown here:

Pardon the mess! This is what the reality of working with
this much stuff in a one bedroom apartment looks like.

In doing more reading and learning, as well as taking suggestions from people on RCGroups, I also modified my ground station plan. Rather than have all the gear on the single tripod, powered by one battery, I have separated out the control portion of the repeater from the video portion. This physical separation will be the simplest way to ensure my UHF signal doesn't cause video issues. It also means that the way I have my control repeater set up now can still be used as-is. That schematic is here:

UHF Control Repeater Schematic

Here is the updated ground station schematic.

Video Receiver Schematic. This is exactly what will be 
on the ground station when it is done in its simplest form

Schematic/Block Diagram for the Sabre

I also decided to visually document all of the physical connections for the components that are onboard the Sabre. The only level of detail that I left out is that it does not show the use of servo extensions.

1.3 GHz Ground Station Schematic

In order to keep my head straight for when I start cutting wires and soldering this new gear together, I find it necessary to plan in a high level of detail. It's not very complicated at all, but when my work bench has 5 components that all need to get connected together properly, it quickly gets overwhelming. Once I have everything, I'll need to figure out the physical layout to determine wire lengths. This part may be tricky because I don't want the Dragon Link transmitting antenna to interfere with either of the video signals, or the 2.4 GHz receiver. It may be trial and error to get enough spacing between components.

I'll post an update once I've built the setup, but I attached a screen capture of my schematic. It is fully comprehensive, including the relevant connector types, and male/female designations.

Microphone in the Sabre

I did a bit of soldering today and got the microphone set up in the Sabre. It required another set of wires to be plugged in to the Vector flight controller. It also required soldering to the audio input wire of the video transmitters. I added the plug to both the 5.8 GHz and 1.3 GHz video transmitters so I can use audio either way. I tested it out and after turning the volume gain way down to get rid of feedback, it works great. It may need some tweaking after test flying to get the volume control set to a good value, but audio definitely comes through clearly on the Headplay.

The whole point is to be able to hear the motor so if I am ever far from home and something doesn't seem like it's behaving right, I can just turn the volume up on the Headplay to make sure the motor is responding properly.

Here's some of the new wiring that went in the Sabre.
The microphone is the tiny green circuit board.

Audio cable is plugged in to the Vector, right next to the Dragon Link receiver.

This is the battery compartment of the Sabre. Now after the wing goes on, the microphone will have to be plugged in the the "AUD" wire, just like the video transmitter has always been plugged in to its own wire that goes to the Vector.

Here's where I currently have the microphone mounted. It's in the aft portion of the payload bay where the other mass of wiring is. I taped it up so it's out of the way, and won't wiggle during flight.

Vortex 230 Mojo

I've been somewhat interested in the modern "race drones" (multirotors or quad copters is all I will call them from now on, because drone is incorrect, and has a negative connotation thanks to the media).

Anyway, since becoming more and more involved with FPV, I decided to try the newest member of ImmersionRC's Vortex lineup, the Vortex 230 Mojo. These race style quad copters are designed to be flown FPV. It comes with everything already installed, including the flight controller, camera, and video transmitter. It will be significantly more convenient to fly than the Sabre, since it is small and portable, and will be able to be flown in smaller places. In general, quads like this are sort of the opposite experience compared to long range FPV. That is, it's high energy and short duration flights, low to the ground.

It came complete as a Bind-N-Fly (directly compatible with my DX20), and ready to fly with modern electronics. I received it in the mail today, and was able to get it set up and did two flights. I'm happy to say it flies amazing. I was pretty intimidated at first but it is truly easy to fly, even in Acro (non-self leveling) mode. My experience with collective pitch helicopters is beneficial, as the controls are similar. I did a few flips in the second flight. The most amazing thing overall is just how much power it has. A split second jab to full throttle pulls over 100 amps and brings it up to 100 feet or so nearly instantly. I'm currently using China Hobby Line 1300mAh, 4S, 100C batteries. Pictures and links to  (boring) videos follow. While I did have the Headplay powered on for the fights, I have not flown the quad FPV yet. I just used it to record on the DVR.

First Flight Ground Video

First Flight DVR

Second Flight DVR

1.3 GHz FPV Gear, Microphone

My intent with my long range FPV setup has always been to eventually switch from 5.8 GHz to 1.3 GHz video frequency. This is due to better long range ability, due to the lower frequency. This is the go-to frequency band for long range FPV pilots. I took advantage of some Black Friday online sales and started getting the equipment to do this.

I have a now have 400 mW 1.3 GHz video transmitter, a 1.3 GHz video receiver, as well as a 5.8 GHz repeater (to allow me to use my Headplay's built-in 5.8 GHz video receiver wirelessly). I also have a Crosshair antenna for use at the ground station, which I will need to do some serious modifications to, since the equipment is bigger and heavier compared to the 5.8 GHz gear.

The ground station will likely consist of a tripod to mount everything to. This will allow for convenient adjustments to the directional antenna, as well as having an elevated, and consolidated place for all the support equipment.

1.3 GHz Video Transmitter (New is Green)

My Bench Test Setup

I don't have all this stuff set up yet, but made some progress. I rigged up the equipment on the bench successfully and it all works just fine. The picture above shows the test bench setup. The video transmitter (green) is rigged up to a battery an FPV camera. The video receiver (silver) is rigged up to power, and to the video input on the repeater. The repeater (smaller and green) is rigged up to the video output from the 1.3 GHz receiver.

433 MHz / 1.3 GHz Notch Filter
This filter is recommended for use at the Dragon Link transmitter. It goes between the transmitter and the transmitter antenna, and is supposed to filter out the frequencies in the range that can affect the video signal.

Ground Station Repeater with The Filter Installed

Microphone
I decided to try to get audio working on my setup. The Headplay SE supports audio so I figured why not experiment with it. The microphone was inexpensive and should be very straightforward to wire in to the Vector and video transmitter. (12/3/17: Updated here.)

I'll post more progress as progress is made.