There's been a few questions about ground station setups so I thought Id share a bit about my setup and why I like to use one for long range and even close range in the park.

What is a ground station?  A video ground station in its simplest is one or more video receivers mounted external from your goggles that accomplishes exactly the same thing as our FPV goggles and module do. It simply receives video signals broadcast from the model and displays the video feed on your goggles, a monitor, dvr, relay, etc. Do you need one? No you don't. But it can help to extend the reliable range of your video link, act as a relay and give some redundancy.

What is a relay? The relay is used to receive one frequency and transmit to another. The video signal from an analog camera is not encoded or processed by the VTX or video receiver. Since the received video signal at the ground station is exactly the same as the video signal from the camera we can re-transmit or relay this with another VTX. 1.3ghz video can be tansmitted and received between the model and the ground station then re-transmitted to 5.8ghz for our FPV goggles. There is very little added latency as the bulk of the latency is in the video processing of the camera and again in the goggles to display the image. To relay the video signal there is no additional processing.

My setup:
2 RC832 5.8ghz receivers with Truerc Sniper antenna. 13db gain 45deg beam (upper)
2 RMRC 1.3ghz recievers and Truerc patch 10bd gain 68deg beam (lower)
eagle eyes diversity
video monitor
eachine dvr
5.8 vtx as a relay




This was designed to be portable and stackable so I can mount just the 1.3 or 5.8 or both receivers. At full extension this puts the antennas around 7ft above ground while the monitor is at a comfortable height. By using receivers mounted on the tripod I can use much larger higher gain antennas that aren't practical to mount to a goggle module. I can point the antennas in the correct direction before I take off and not have to worry about keeping my head pointed in the perfect direction at all times especially with the narrow beam of high gain antennas. Adjustments to the antenna aim can be done on the fly by myself or a spotter, the monitor lets a spotter see the FPV feed to fine tune adjustments or allows me to remove my goggles to do it when I'm flying solo. (ignore the chick with the mullet in the picture, she came with the pool table haha)




For Diversity Im using an eagle tree diversity (discontinued) that also acts as a 4 way splitter. I added some 5.5 barrel connectors to the case and used these to supply power to everything on the ground station. The eachine DVR is wired to the bottom RCA video out, I can see the DVR menu when the monitor or relay is plugged into this connection. To do this I severed the RCA connection to the board and wired the video out from the board to the DVR video in and the video out of the DVR back to the RCA connector. This DVR adds lots of latency to the video feed, after starting the recording I can move the monitor RCA to another video out that does not have the DVR display while it continues to record. I wanted to keep this is all RCA connections rather than 3.5mm jacks like the 5.8 receivers had so I found the pinout and soldered an RCA cable to it. 




The relay is a cheap 5.8ghz VTX and a 3d printed mount that snaps it in place on the bottom of the tripod hidden inside the tube. The vtx is soldered to a cut off end of an RCA cable with a 5.5 barrel power connector added to it. To use the relay I simply plug in the barrel connector for power and RCA ends into an audio/video out from the eagle eyes then turn on my goggles. With 1.3ghz video I can use any FPV goggle and regular 5.8 module. When not in use or plugged in the cable wraps around a 3d printed reel mounted below the tripod head. A 3d printed cap keeps the VTX covered and protected at the bottom and at 25mw output I have all the range I need to freely move around the ground station area and there's no need to have any ventilation or cooling for the VTX. 




How does this help extend my range?

Spotter Station.
I built this so a spotter or myself can have easier LOS and FPV video feed. With a spotter they can give much better assistance and call out landmarks that I can actually see and guide me home or prevent me from flying behind object, below a hill. This has proven to be a huge advantage of this rig especially since I fly in mountainous areas where getting turned around is very easy and failsafes can be instantaneous when you put a mountain between yourself and the quad. It also helps keep the spotter engaged to focused.
Flying solo I can use the monitor rather than my goggles while positioning myself so I have LOS at a glance. this is very handy for an Arial photography drone and for autonomous way point missions.

1.3ghz
A ground station is really the way to go to get the most out of it. There are goggle modules around but hanging a patch antenna off one is not going to happen. This frequency also has much better penetration than 5.8 making CP antennas less needed. For a smaller quad a simple linear monopole or dipole has worked very well for me and I will run out of battery long before I run past my video range despite the linear/ CP mismatch between the transmitting / receiving antennas. With a good setup 20km+ has been acheived with many of these components.
The disadvantages of using 1.3ghz is that CP antennas can be huge and the video quality is reduced compared to what we are used to with 5.8 analog video. Theres also currently no 1.3 VTX that works with betaflight smart audio or tramp, most do not have adjustable output anyway.

5.8ghz
I generally fly using my goggles for the fpv feed with lower gain and broader beam antennas just for the ease of use. I have this running for the spotter, DVR and redundancy since the higher gain antennas generally have better range than my goggles do. My spotter can work to maintain the video link on the ground station and when I loose video on the goggles I can lift them up and continue on or turn around with the ground station monitor until im back in range of the goggle antennas. Its much harder to fly from the ground station monitor when your not used to it so I can tether to the ground station with the 3.5mm input cable if I want to keep using the goggles. I haven't tried the relay when using the ground station with 5.8 because it could stomp on the signal from the quad. Someday I will have to experiment with this.

Some considerations if your building one.
This is much more comprehensive than you need for a basic ground station so don't get intimidated if you've been considering building one. My first one did not have diversity and despite some people insisting diversity is an absolute requirement for a good ground station, it is not for long range. The greater the distance from the antenna the wider the area it covers, even with the narrow 45deg beam of the 5.8 sniper antennas I use the effective area it covers can be miles across if I'm a significant distance from the ground station. I prefer to use 2 patch antennas spread about 30deg apart rather than an omni, two patches really do nothing other than give a bit more area in the sweet spot so i have less adjustments rather than give any increased range. The eagle eyes diversity is really nice though for the video splitter and cable management and the diversity really does help reduce adjustments with 2 patches. An onmi is best for close range where I really don't need a ground station anyway more relevant to a wing than a quad where I can cover a lot more distance quickly if Im flying around myself. I often bring this out to the park anyway if I'm planning on being there for a while. It lets people see first hand what FPV is all about if they come by to ask questions.

Impressive setup. And people like me are still considering upgrading the patch on my goggles to an X2-Air

Hi EVILsteve,

That is really impressive. I am still trying to digest it all; and see if I can actually figure it all out.

At this point, I am still somewhat confused    
As I work through it, I will likely have questions. Thanks for starting this thread.    

(05-Jan-2021, 01:59 PM)kafie1980 Wrote: Impressive setup. And people like me are still considering upgrading the patch on my goggles to an X2-Air

Thats the patch I use, Ive been very happy with it. I really considered putting those on the ground station as well.

(06-Jan-2021, 02:19 AM)iFly4rotors Wrote: Hi EVILsteve,

That is really impressive. I am still trying to digest it all; and see if I can actually figure it all out.

At this point, I am still somewhat confused    
As I work through it, I will likely have questions. Thanks for starting this thread.    

These really are not nearly as complicated as mine makes it appear. Today I built a very simple version of a 1.3ghz relay station for a friend that's interested in doing some long range wing flights with me this weekend. Id took some snaps that show how these work a bit better without all the extras.

For interest sake I placed some antennas in the photo. On the left the green antenna is a 1.3ghz dipole compared to a 915mhz R9 antenna above it. This is what I typically use on an fpv quad. The middle is a VAS cloverleaf 'mad mushroom" and a true RC singularity on the right. These I use on fixed wings or a large aerial photography platform. You can see how these compare to the axii on the 5.8 vtx.



You can see from my wiring harness how simple these are. The pic got a bit blurred with the imgur upload.
BLACK    -Batt Neg -
RED       -Batt Pos +
YELLOW -Video -from 1.3 receiver rca cable to vtx video in
WHITE   -Audio -from 1.3 receiver rca cable to vtx video in 

A newer vtx with smart audio might use a mic on the vtx and will not transmit audio from the quad. Old vtx's with an audio solder pad work great for these or most cheap amazon vtx's are perfect for this use, 25mw is all you need. This AKK I'm using here will not transmit audio from the quad. The white wire is soldered onto the smart audio pad just to tidy things up until I get a better vtx for the purpose.







This is all you need for a basic setup for a 1.3, 2.4 ground station with a relay. This tripod mount is what I used for years, its a plate welded to a steel rod to mount the receiver and a nut welded on the bottom to threas onto a standard 1/4" 20 thread of a tripod. My first ground station before I had a welder was on a painters extension stick duct taped to a chair with the rca cables plugged into the goggle video in port. 

Diversity really isnt needed with quads for long range, we tend to pick a target and head to it making aiming a ground station very easy. Getting this higher has proven to do more than making it a complex diversity setup with an omni antenna, that's why I use dual patch antennas on the ground station for quads. Even when I'm behind the ground station I'm still easily getting reasonably clean video for a decent range with some minor breakup.

This is the simple relay station in action. I'm transmitting 1.3 from the quad and receiving with the simple relay station then re-transmitting to 5.8 where I can pick it up on the goggles or any 5.8 receiver such as the immersionRC Uno5800 receiver like I'm using in the photo to display on a TV screen. My more complex version uses a diversity module. I twinned the 1.3 receivers and feed both video signals into the module where it selects the better video signal. The eagle eyes module that I use also acts as a video splitter and I added 5.1 barrel connectors to it so its a power distribution hub as well. I can just plug the TV into the module with rca cables or a dvr etc. 




Some build Pics. I designed most of this when I was stuck quarantining for 3 weeks. I modeled as much as possible in fusion 360 to save on revisions and wasted filament but there was still a few measure once print twice mishaps.  




Antenna tracker I've been working on so I'm not reliant on the diversity module for 5.8. I found a very early octocopter on the local classifieds for cheap and set it up for a co-pilot to operate a gimbal. I thought would be a fun way to get other people involved with no experience. Spektrum servo is used for pan movements, Arduino micro for control.  

Hi EVILsteve,

Nice Rack 

So, just an external receiver is used on the ground station to pick up the signal     
Then the signal is wired to a VTX transmitter that re-transmits the signal to the goggles 

Do you have links for the "external receivers" that are used on the ground station to pick up the signal from the craft ??

Very cool designs, I myself am just not at the technical stage to build one. Would anyone be interested in selling their groundstation? Or building one for sale?

My thoughts would be patch and helical for 5.8 video, 915 Yagi for telemetry