2014 in review

Posted: December 30, 2014 in X8 Wing

The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 19,000 times in 2014. If it were a concert at Sydney Opera House, it would take about 7 sold-out performances for that many people to see it.

Click here to see the complete report.


Posted: March 1, 2014 in Articles

Here is a list of terms commonly used in FPV. It will help to demystify some of the things that you may read. If you have any questions come into the forum and we will help and advise you. If you have any suggestions on additions to the list or corrections then please let us know.

FPV First Person View
Dbi Decibel Isotropic
Diversity Tracking Diversity Tracking
A dual receiver system that monitors the RSSI signal strength and picks between multiple antennas to display the best picture possible
Ghz Giga hertz
GPS Global Positioning System
Used with OSD`s to give real time positioning of your plane and used to display distance from base, altitude, speed and to guide plane home if RTH feature is engaged and antenna tracking using multiple satellites.
Grid Highest gain antenna, larger and very directional
LOS Line Of Sight
in the UK legally when flying your plane you must still remain in your line of sight, or the spotters. If you cant see the plane you have gone too far
Mhz Mega hertz
OSD On Screen Display
Patch Patch
A higher gain panel antenna normally 8 / 14 dbi, longer range but limited angle of sensitivity 30 – 40 degrees of view
Polarization Polarization
A matched polarized signal has both the transmitter and receiver signals matching in pattern having a large cross section of the signal returning to receiver and providing a great picture. Once a plane backs and / or polarization of the signals don’t match very well the intersecting cross section is small and gives a low quality or no picture.
RSSI Received Signal Strength Indication
Voltage signal to enable signal strength monitoring, many receivers both radio and video have a RSSI pin on the board, this can be exploited and used to indicate signal strength normally displayed in a percentage to indicate strength or packets of data lost. The higher the packets lost the high the chance control or picture degradation will occur
RTH Return to home
Return To Home is a feature built into some OSD devices which when too many packets of radio data are lost assumes no signal to plane and uses 3 axis sensors and servo control coupled with GPS and knows Base GPS coordinated to guide the plane back to you to hopefully regain control
Rubber duck / Whip Refers to an Omni antenna. Usually stated as a 3dbi gain antenna but is really closer to 2.14dbi
Vario Variometer
Sometimes built into a OSD, somethings a stand alone unit used to display or audibly indicate the planes angle of attack and rise and sink rate useful with sailplanes and gliders in general
Vtx Video Transmitter
Yagi A even higher gain antenna, normally 18 dbi but even more directional

Note: Misconception of multiple antenna, some people are under the impression you have to use an omni antenna along with a patch because the patch is directional. But this is wrong, the patch`s pattern even though directional can see behind it to a degree and can just be used by itself although the omni would give greater rear reception

A Video about antennas etc – very informative.


Antenna Tracking

Posted: March 1, 2014 in Articles

What is antenna tracking ?

Antenna tracking is used in FPV to direct the video receiver antenna at the aircraft as it flies around the sky.

Here is a video of the Myflydream tracking in action. A GoPro has been attached to the front of the tracker so you can see exactly what the tracker is pointing at

Why do we use it ?

We use it for a few reasons. One reason is antenna gain. With different types of antenna they all have different characteristics. One of the characteristics is its gain. The higher a gain of a receiver antenna the further out it will pick up a signal. But with this advantage comes a disadvantage of it needing to be pointed towards the aircraft. On the ground if you use a high gain antenna and it is not pointed at the aircraft to a degree then the picture is lost. The higher the gain of the antenna the more critical this becomes. Another consideration is polarization. If you were to say use a Circular Polarized antenna, the antenna has higher gain than a omni or rubber duck. But with this it still needs to be in the general direction of the plane. The advantage of this type of antenna is that it has low signal loss in banked turns and rolls. So to use the advantages of the higher gain or Circular Polarized antennas you need a way of pointing them at the plane as is flies while you have the goggles on flying it. Enter the antenna tracker.

So why don’t we just use omni antennas and not have to worry ?

With an omni antenna you have a gain of 3dbi ( normally less. ) This limits the range we can fly and being linear in polarization some or all signal can be lost while performing banked turns or acrobatics of any kind. With a Circular Polarized patch this is not the case with maneuvers, with a high gain antenna the range is not a problem anymore.

What does a tracker do ?

The antenna tracker uses information collected to physically move the antenna on the pan and tilt axis to have a direct path to the plane.

How does it work ?

There are a few systems available. Even some DIY systems.

Commercial systems

The main systems commercially available use data sent to them from the plane as it flies. This is in the form of telemetry. On starting up the plane the GPS coordinates of the plane are stored as “Home” this is a reference point for the trackers location. Then as the plane flies it relays the positional data of the plane to the tracker, the tracker then works out which direction and height the plane is from the “Home” reference and can point to the plane and track it in the sky. The data is sent normally in one of two ways, either down the audio channel from the plane or the video channel encoded into the signal. The tracker monitors this and extracts the telemetry and processes it before commanding the servos that control the pan and tilt axis of the antennae to move.

DIY systems

On a recent DIY system invented by IBCrazy, the system uses three antennas, two compare the RSSI signal from the plane. The higher the RSSI signal ( Receiver Signal Strength Indication ) the more the antenna turns to that direction ( either left or right ) until they are both equal. This then means the antenna directly in the middle is now pointing directly at the plane at all times. The system seems to work very well. It is limiting in its size, being that three antennas are needed. In both cases what you have is a directional antenna pointing at the plane at all times giving you the best possible signal for video, and the best signal for the tracker at the same time. The commercial units all use GPS to work, the DIY version does not need this. Both however depend on a signal being received, if no signal is being received the tracker will stop. So it is not ever 100% perfect. They do however open up a much more flexible way of flying and video enjoyment you can get

Separate Lipo`s

Posted: March 1, 2014 in Articles

Battery choices

A topic often discussed in FPV is regarding batteries. The option of using another separate battery from the main flight battery dedicated to the video.This topic is thrashed out on many forums on a weekly basis. Here is what my personal finding have been on the subject.

So if this option is available then its the best route ?

Well that depends. What we have found instead is the there are pro`s and con`s to each system. Lets look at the differences


1 Battery system :

Only one lipo to charge and remember to charge.
Only one failure point
Lighter aircraft
More room available
Less connections
Simpler system

2 Battery system :

Separate supply for both flight and video system for cleaner signal and redundancy
More stable operating voltage with no voltage drop during motor running
If flight lipo fails video will still run enabling flyer to see impact point

Cons :

1 Battery system

Only one lipo to depend on whole system working
If the flight lipo dies control of plane is lost
If a 12v video system is used with no step up voltage supply for it and lipo dies video is lost

2 Battery system

Both batteries have to be charged each flight
Both batteries have to be monitored
Double the failure points of the power system
More weight in the plane for less capacity
If flight battery dies flight control is lost

Lets breakdown the pro`s :

1 Battery system :

Only one lipo to charge and remember to charge – Running off the single supply as it says only one battery to charge – On a dual battery system two lipos to charge and monitor

Only one failure point – One set of connectors to fail, one set of cells to fail – On a dual system, two sets of connectors and cells are now potential hazards – Double the risk

Lighter aircraft – If using a single lipo system the aircraft can if chosen be lighter – On a dual lipo system it will either be heavier or you will have to sacrifice some flight capacity to keep the weight down

More room available – With a single lipo system more room is available for RTH devices or OSD units. In most FPV planes space is tight or space between components is desirable – On a dual lipo system more room is taken up by the additional lipo reducing flexibility for equipment placement

Less connections – As failure points on a single lipo one set of connections – On a dual twice as many to fail mid flight

Simpler system – On a single lipo system, one source of power less complication, easier to fault find – On a dual system, twice as many points to fault find

2 Battery system :

Separate supply for both flight and video system for cleaner signal and redundancy – On a single system a simple LC Filter is used to clean the supply to components – On a dual system the filter is not needed

More stable operating voltage with no voltage drop during motor running – On a single system a step up can be used, or if using a highly recommended 5v system then the voltage never drops below operating voltage anyway – On a dual system this is not needed

If flight lipo fails video will still run enabling flier to see impact point – On a single lipo system using a step up or 5v system this is also the case – So no additional benifit from a dual lipo system

Lets breakdown the con`s :

1 Battery system

Only one lipo to depend on whole system working – On a single lipo system with a step up or a 5v system this means video works even after a cell has failed. If main lipo fails then the system goes down – On a dual lipo system the video works if second lipo is charged but if flight pack fails control is lost so that doesn’t really matter anymore

If the flight lipo dies control of plane is lost – On a single lipo system this is true – On a dual lipo system this is still the case

If a 12v video system is used with no step up voltage supply for it and lipo looses a cell the video is lost – On a single lipo system this is why we use a 5v video system so its not – On a dual lipo system as long as video lipo is charged this does not happen

2 Battery system :

Both batteries have to be charged each flight – Not so with a single lipo system – True with a dual, forget to charge the video lipo and you are in for a surprise mid flight

Both batteries have to be monitored – With a single lipo you can time your flights or use a lipo alarm – On a two lipo system you have to monitor both at the same time, either two lipo alarms to use or an OSD with two separate readouts and two values to concentrate on while flying as well as everything else

More weight in the plane for less capacity – On a single lipo system, one lipo full capacity for the weight – In a dual lipo system either the plane has to weigh more or the flight lipo has to be reduced in capacity to keep the weight down

Finding `s:

So looking at it on face value, at first glance the two battery system seems to have an advantage over the single in the video will still be active if control is lost. But having said that most video systems will run on 5v or be 12v systems that will still continue to work below 9v ( failure point of a 3S system. ) What is recommended is using a 5v video system, camera and Vtx. This way you can run a lipo till its dead or loose a cell and your video will still work absolutely fine so this then now fails to be an advantage for two separate lipos.
The second advantage is having the video supply isolated from the flight supply thus isolating any interference in the video. Yes this is partly true, but then even if it is isolated if the two separate systems wires are run in parallel with each other at any point in the aircraft the interference can transfer over to the video supply anyway. With a single lipo system sometimes you don’t get any interference ( if you lucky ) if you install a ferrite ring or an LC Filter it will cure this. So that’s another advantage that`s not actually viable.

So as we look further into this the more apparent that the initial pro`s of a dual lipo system seem not really that good after all. Now take into account charging. How many times have you forgot to charge your transmitter before going to the field ? Now you have to remember to charge your video lipo too. If you forget, that’s your FPV flying out the window for the day. With the single system if you have charged your flight pack your great to go.

If you run two separate lipos on board you have now doubled the chances of failure.

We can achieve the same result as running two lipos with one. By running a 5v video system.

Some argue that with a separate lipo for video if your flight lipo fails you can still watch the impact and find the plane. You can on a 5v system too. Either way the same thing will happen. If flight controls lost the plane is no longer under control. The plane is coming down and chances are not to a nice smooth landing. No amount of video is going to save that from happening.

Here’s an example :

Take 2 planes, If you use two batteries you have less capacity in the flight battery ( if both were identical planes ie weight ) because the video battery would take up space. Therefore even though your video would be fine your flight times are now reduced. Now take the 1 battery plane with a larger capacity flight battery, the video still works as its on 5v through the whole pack but the pack is bigger. Bigger pack = longer flight. 5v system means video always works so advantages of running a second battery now seems insignificant

So from what we see, every advantage of a second lipo on board can be matched by a single system on every account. Thus negating the need for running a separate lipo

Vtx Power and Range

Posted: March 1, 2014 in Articles

Vtx power rating

One common misunderstanding is the power of your video transmitter. The first thing to remember is here in the UK we are bound to regulations restricting the power outputs of our video transmission.

Why are we limited ?

We are limited in power levels for various reasons, for 2.4ghz for example in the UK wifi runs on this, so does bluetooth and of course RC control transmitters. In the UK we are limited to 10mw of transmission power on 2.4ghz so we do not interfere with any of these other services. On 5.8ghz we are limited to 25mw.

Why are there bigger transmitter available ?

In the rest of the world these regulations do not stand so the equipment is legal to use and widely available.

How do we understand power levels ?

The mw rating of a transmitter is the RF level emitted from the antenna into the environment, is measured in milliwatts or watts.10 milliwatts is ten one thousandth of a watt or 0.01 watts.

On 5.8ghz we are regulated to 25mw of transmission power. Now 25mw sounds 2.5 times more powerful than the 10mw limit of 2.4ghz. Sadly not true, the 5.8ghz wavelength is half the length of a 2.4ghz wavelength so travels half the distance on the same amount of power. To increase the range to match the range of the 2.4ghz wavelength on 10mw it again needs 4 times the power to double the range. So to get the same distance of a 10mw 2.4ghz transmission the 5.8ghz needs to be broadcast at 40mw.

So with the limits we have on our transmitter how do we improve the results ?

Most will increase the power of the transmitter, but to do that is illegal and its not very effective.

Take the 10mw transmitter for example. To double the range of that transmitter its not as simple as doubling the power. To double the distance of it you have to increase the power 4 fold. So to double the 10mw range you would need 40mw. To double the range of that you need 160mw and again to double that range ( still talking short range ) you now need 680mw.

As you can see that’s a lot of power for not a lot of gain. Coupled with the legalities its not the way to go about it.

How do we increase range then ?

To increase the range you increase the gain of the receiver antenna. By increasing the reception by 3dbi you have doubled the range, add another 3dbi and you have doubled it again. All without increasing the vtx power and staying completely legal to boot.

Your standard omni antenna had a typical dbi of 2.14 not 3dbi as advertised. So if you were to buy say a 17dbi yagi antenna you have now increased your receiver dbi from just over to 17, that’s 15dbi +/-. 15dbi divided by 3 gives us 5 times the range you think. Well no. 3dbi gain doubles your disance, another 3dbi on top doubles your new distance. So by increasing the gain from 2dbi to 15dbi actually increases the range by 32x its original distance ! All this without increasing the vtx power at all !

This is where some club fliers not in the know don’t understand and fear. Because you can receive from much further away you must have increased the power ! No you just improved your reception.

Look at your tv antenna on your house wall ( Its a high gain Yagi. )

If you have one of those cheap alien looking devices from argos sat on your tv box you picture is rubbish. Now plug in your tv arial attached to the house and suddenly perfect picture ! Has the transmitter suddenly increased their broadcasting power ? No. You just increased your antennas gain by swapping from the low gain poorly positioned antenna indoors to your high gain better positioned yagi outside. That’s all !

So using a high gain antenna such as the Yagi mentioned can increase your range by up to and over 30 times its original limit. For legal flying in the UK ( within LOS ) that’s all your going to ever need.

This is where some misunderstanding has been publicised in RC forums around the UK. Some LOS flyer’s have been reportedly had their 2.4ghz rc control planes dropped from the sky. FPV fliers get the blame. Its a case of not understanding how the power from vtx`s work and its limitations. Whats also sadly gets blissfully ignored is commercially available wifi boosters ( also illegal ) that operate on 2.4ghz used in homes surrounding flying fields. Also commercially available video transmitters on 2.4ghz and 1.2ghz ( second harmonic of 2.4ghz ) at illegal power levels. These are available online with power ratings typical of up to 4 watts in power. As has been stated the increase of power has not a lot of effect and very poor increase in range, but a 4 watt + transmitter within close proximity of a flying filed does have detrimental effects.

All we can do is stick to the regulations and use high gain antennas in a more efficient manner to get the results we require. That way we keep FPV in a good light.

Video Frequencies

Posted: March 1, 2014 in Articles

As you look deeper into FPV flying you soon realise there are lots off different brands of equipment available and whats more lots of different frequencies open to buy.

The equipment available is for use world wide. But as with all countries the UK has only a select few that we can legally use, that are open to us.

Not only are there certain frequencies that we are legal to use but there are also constraints on what power levels we can transmit legally on as well. The transmission levels though are another subject entirely. In this article ill concentrate on frequencies only

So what frequencies can you get video equipment for :

900 Mhz
1.2 ghz
1.3 ghz
2.4 ghz
5.8 ghz

So whats the difference ?

The lower the frequency band, the larger the waveform produced. The larger the waveform the further it travels, the better it can get round or penetrate objects such as small buildings, trees and people.

So in that case the obvious choice is go out and buy 900mhz video equipment ? Not that easy I’m afraid

The 900 Mhz band

Nope, if only it were that easy…….. Unfortunately the government opened the 900mhz band to the mobile phone industry in 2009 so that the 3G phones could be used in this country.

Ok so so that 900 ruled out, how about 1.2ghz, well again as a resident of the UK again this band is not available for us to legally use.


The 1.3 Ghz band

The myth regarding 1.3GHz comes mostly from our American cousins, because, if they have a ‘Ham’ licence, they can use 1.3GHz for FPV. A Radio Amateur can use 1.3GHz for transmitting video/audio (Amateur Television or ATV) only from a ground based station.
The moment it is used for aerial work, I’m as illegal in the UK.

Not so straight forward is it ? Well don’t worry its still easier to get your head round than the thinking of a woman…….. So now we get to 2.4ghz systems :

The 2.4 Ghz band

2.4Ghz video equipment is very popular. Its the most commonly made equipment and generally is the cheaper of all the bands to buy. It has good range / power ratio and is sought after by many.

Hip hip…………… Hang on………..
Yes you guessed it, there’s a problem. The problem with 2.4ghz is that with the launch of the Spektrum and Futaba 2.4ghz radio control equipment you cant use your 2.4ghz video equipment around any 2.4ghz radio user.
Their equipment will interfere with yours and spoil the picture being broadcast.
Another downside of the 2.4ghz video is it has poor object penetration properties and buildings trees and people can all have adverse effects even completely loosing picture.
So when you fly with 2.4ghz video you have to remain in Line Of Site to the plane.

So this brings us alone to …………………..

The 5.8 Ghz band

5.8 Ghz is growing in its popularity. This band is useful because its off the 2.4ghz that most flyer’s will be on so that’s that problem solved. Its got a decent range / power ratio but again as the 2.4ghz has very poor penetration properties so Line Of Sight flying only. It did have poor reception due to polarization and multipath, this now has been solved with the rise of the circular polarized antennas. It can now be used practically to great ranges without issue and has now proven itself well worth considering amongst FPV pilots. It is most useful for multicopter pilots as the vtx can be in close proximity to everything else with no adverse effects, which is the only option on multicopters.

So lets sum up :

900 Mhz :

Pros – Brilliant range, great penetration
Cons – Illegal for use in the UK, band used by mobile phones

1.2 Ghz :

Pros – Great range, good penetration
Cons – Illegal for use in the UK, band used by other sources

1.3 Ghz :

Pros – Good range, good penetration, very clear band
Cons – Not legal for airborne use in the Uk

2.4 Ghz :

Pros – Good range, cheap equipment price, lots of none FPV equipment on the 2.4ghz band can be used with FPV equipment such as antennas
Cons – Bad penetration properties, band used by other flyer’s, wifi equipment, bluetooth etc.

5.8 Ghz :

Pros – Good range, cheap equipment price, band very clean due to low amount of other users. with circular polarized antennas no loss in reception quality.
Cons – Very poor penetration

So what do we all do ?

Most popular method is to adopt 35mhz radio control for our platforms. This gives us good range and faultless results as the 35mhz doesn’t effect the video signal at all. Although with UHF ( 459Mhz ) on the increase this then opens up to possibility of using 2.4Ghz video if not club flying.
This keeps us all legal, we have good control, good video quality and providing we respect other 2.4ghz flyer’s and keep away enjoy the best compromise we possibly can

Radio Frequencies

Posted: March 1, 2014 in Articles

The 27 Mhz Band – Illegal to use for radio controlled aircraft

The 35 Mhz Band

It was the most popular and commonly used band in the FPV sector. This band has very good range properties over 1 mile range with standard equipment. It is being overtaken now with UHF systems becoming available on UK legal bands with none of the 35Mhz pitfalls

The downside of this frequency is the ability for another user to be on the same frequency by mistake and shoot your FPV platform down. This is why at meetings everyone’s channels are logged down and channels are assigned to users so two channels can not be used at the same time.

To identify your channel on known crystal frequencies :

Channel 55 34.950 Channel 67 35.070 Channel 79 35.190
Channel 56 34.960 Channel 68 35.080 Channel 80 35.200
Channel 57 34.970 Channel 69 35.090 Channel 81 35.210
Channel 58 34.980 Channel 70 35.100 Channel 82 35.220
Channel 59 34.990 Channel 71 35.110 Channel 83 35.230
Channel 60 35.000 Channel 72 35.120 Channel 84 35.240
Channel 61 35.010 Channel 73 35.130 Channel 85 35.250
Channel 62 35.020 Channel 74 35.140 Channel 86 35.260
Channel 63 35.030 Channel 75 35.150 Channel 87 35.270
Channel 64 35.040 Channel 76 35.160 Channel 88 35.280
Channel 65 35.050 Channel 77 35.170 Channel 89 35.290
Channel 66 35.060 Channel 78 35.180 Channel 90 35.300

To identify the channel number of an untagged crystal:

If your crystals have the frequency stated but not channel how can you define which channels it on ?

Well that depends on what the crystals marked up with, either 34. something or 35. something.

If its marked 34.___ then you take 40 from the numbers after the decimal place, so for instance if its marked 34.950 then take 40 off the 95. This gives you 55, so its on channel 55. If its marked 34.990 then take 40 off the 99 and you get channel 59.

If the crystals are marked 35.___ then you need to add 60 to the numbers after the decimal. So crystals marked 35.180 would be 18 + 60 = 78, so that would be channel 78. Crystals marked with 35.240 would be 24 + 60 = channel 84

All 35 mhz radio control equipment must carry an approval sticker or an official CE marking. Equipment bearing either of these markings shows that the equipment has been tested and approved for use in the UK.
If your 35 MHz equipment carries neither marking, it may not be suitable or fit the criteria required for safe use in the UK.

The 40 Mhz Band

The 40 Mhz band is for land based RC only, no airborne use allowed

The 72 Mhz Band

72 Mhz is not a legal frequency for the use of any model control in the UK and should never be considered

The 2.4 Ghz Band

2.4Ghz has gained lots in its popularity over the years, its a viable choice of band for FPV control, has decent range and means you can fly amongst other 2.4 users with no problems. The 2.4Ghz systems use FHSS or Frequency Hopping Spectrum Spread technology. What it basically means is that instead of being tethered to the one channel on the band, the transmitters output hops between several channels back and forth. The signal from each transmitter is encoded and has its own signature. This is so many users can hop across the same channels without conflicting with each other. The only thing is as time has past a lot of users have reported brownout problems with some of these systems and rebinding takes to long as the plane falls out the sky. This is normally Spektrum DSM2 systems that were behind the times with technology. Thankfully Spektrum have now released DSMx radio`s that are a lot better now. Futaba`s FASST systems never had this problem.

If you are using an old 35Mhz radio and would like to upgrade it to 2.4Ghz this is easily done. There are now 2.4Ghz upgrade kits available from companies such as FRSKY that manufacture these units that also can incorporate telemetry connection with the plane so you can monitor key values such as battery condition as you fly.

The other problem with 2.4Ghz radio control is you cant use it with 2.4Ghz video gear. It is not because of the ill informed opinions that 2.4 video devices can down 2.4ghz planes, its simply because the 2.4Ghz control signal wrecks the 2.4Ghz video signal as it hops about the band. In which case the use of 5.8Ghz video solves all this in one easy fix. 5.8ghz being a much cleaner band tends to have a lot less interference problems associated with 2.4Ghz video as well.

UHF Band

The 433 Mhz UHF Band is a popular choice abroad. Its used in many FHSS (Frequency Hopping Spread Spectrum) systems for very long range of many km. One manufacturer has recorded full control in excess of 25km away. Claims go up as far as 70km possible.

Again 433 Mhz band even frequency hopping technology is still illegal in the UK.

In the UK 459Mhz is the allocated band for UHF airborne control systems. Until recently there were no such commecial systems available to us, but ImmersionRC have now made firmware available for UK users which enables EZUHF to use the 459Mhz band and with UK legal 100mw output. This system is one of the best available. Many FPV users now use UHF exclusively because of the clear band and the huge range even the UK legal units offer.

There are no UHF radios to buy off the shelf though. To have your system as a UHF system means checking its compatibility with your current radio, then connecting the stand alone UHF unit to it. This is normally just the power wires for the UHF system and a PPM signal for the UHF system to broadcast. So a little research and DIY is required sometimes. Futaba radios though are normally catered for as there trainer socket can be used to simply plug into to meet the above criteria. Some UHF systems are sold with the optional Futaba plug enabling the unit  to be plug and play out the box.

If you are a little more hands on, the OpenLRS system from FLYTRON is an open source UHF system that is able to use the 459Mhz band as well. This is a more involved setup, you need to be familiar with Arduino programming, or at least know how to connect and flash the transmitter and receiver to program the units through Arduino 0022 or above. Once flashed though it is a simple case of plug and play. The great feature of this system is that when you program it through the easy to use software you can choose how many channels it hops over, exactly which channels if you so wish and change the signals unique signature to what ever you want. It is still in its infancy with 459Mhz testing being done daily, but results so far exceed predicted hopes.

Ground Stations

Posted: March 1, 2014 in Articles

Welcome to the wonderful world of Ground Stations section

What are Ground Stations ?

You here a lot of people talk in the forums and mention all the time a GS or Ground Station. Lets look into the concept of a Ground Station. Its as clear as mud this subject unfortunately but hopefully you will get the idea of them as you read on.

So what are they ?

A Ground Station is a term given to the equipment on the ground that receives the signal and processes it. Its a generalization.

We all know that from reading on this site its the receiver and antenna that receives the signal from the plane. The goggles or screen that displays this. But combined together and mounted in a package is what a Ground Station is.

What does a Ground Station consist of ?

Is it just the receiver and goggles ? No the term Ground station covers the arrangement and collection of equipment as one unit. It can consist of as many or as few a parts as what the user wants / has

Ground Stations cant be bought. The components can but the components installed into some sort of box, tripod or back pack then collectively become the Ground Station.

How do i make one ?

That`s the 64,000 dollar question. It depends what you have, what you want to put it in.
There’s no right or wrong way to go about one really, unless you position or mount antennas badly.
Every single ground station is different.

What should i be considering ?

Lets generalise a Ground Station, let say you you are starting off. You will need a Receiver, and Antenna, a power supply for the receiver.Goggles to plug into the receiver. This is the most basic component level of a Ground Station.
This will get you to the point of receiving and displaying the planes video to you so you can fly. Nothing more. All you need to do is have them so the antenna is mounted properly, the battery for the receiver safe and accessible to recharge and the outputs an channel selector of the receiver in an accessible fashion.
Put your components into on onto the Equipment you want to keep it in. This can be as simple or as extravagant as you wish.

My own first loosely named Ground Station consisted of just this. I had a Lipo elastic banded around my receiver, a rubber duck antenna direct to the receiver and that was it. It worked fine and was as basic as it got.

As you progress in the hobby, your Ground Station will grow in size and features. As you learn you begin to realise that certain antenna perform better at certain heights. You want a video recorder. You need to split the video signal. Maybe diversity is chosen. You get into antenna trackers, then you need to mount the tracker to something. Your Ground Station.

Now you have all these components which need putting into or onto something. Now thought has to go into your Ground Station. Now you can get as creative as you want :)

Remember to ensure components run cool with sufficient cooling, everything with plugs you plug in or unplug often are accessible and all your equipments voltage ranges are catered for. Make sure you can charge or take out to charge any batteries.

So what should i put it all in ?

Whatever you want, the more lightweight and practical the better.

Some use tripods and have the equipment mounted to the legs with antenna on the top. Some are housed in boxes that mount to the top of the tripod. Others simply use a box.

Its up to you

Pan and Tilt

Posted: March 1, 2014 in Articles

Camera Pan and Tilt

The ability of your camera to Pan and Tilt is a great feature for the more experienced FPV pilot. The ability to look down the wing while you make a loop or have a good look around your flying environment is a very welcome feature.

To do this is pretty simple. How effectively you do it is based on a few factors.

How to do it ?

You need a system that the camera is mounted to that rotates on 2 axis, horizontally and vertically.

You need two channels available on your transmitter to control the axis, pan and tilt.

You need two servos, although more crude pan and tilts can use just the one servo. With using one servo you have little control over the tilt function so we will concentrate on the two servo total control only.

Camera mount systems :

There are lots of different systems available on the market, some are better than others, some are very light weight others more robust but weigh more

Here are two examples of such a system :

A fibreglass bearing mount from companies such as hobbyking

A metal version, very simple but effective

As you can see the mounting of the camera in both systems are different and for different types of cameras.

The camera is mounted on the base of by the lens and pivots on their axis by the servos
As the servo horn moves through its travel the camera is pivoted up and down, left or right.
The amount of travel can be limited by the endpoints of your transmitter. On the pan, generally you want as much as possible, but on the tilt limits can be set so the camera doesn’t come into contact with anything, jamming or burning out the servo.
Most servos even at 100% travel dont go much further that 90 – 120 degrees of travel.
On the tilt this is not a problem but on the pan sometimes users want more travel. Up to 180 normally.
To get the required travel a servo stretcher is used, this plugs into the servo lead, then the endpoints are adjusted on the transmitter to achieve 180 degrees.

You can mount the pan and tilt wherever you want on the plane to get which ever perspective you like.

Video Splitter

Posted: March 1, 2014 in Articles

Whats a video splitter ?

Just as it says really, a box ( normally) that takes your video output from your ground stations receiver and splits the signal to multiple outputs.

Why do i need one ?

If you want to use multiple screens, an extra screen as well as your goggles or to a recorder of some type you will need a splitter. Another problem is with regards to video levels. Some equipment like the recorder may not like the video level it receives by a basic video splitter, so you will have to go down the adjustable output video splitter route to fin tune each output to get the best picture for each display / recorder.

Why cant i use a Y splitter lead ?

The video signal degrades with the more its split, the picture quality diminishes and eventually becomes unusable. You can split your audio this way with no ill effects but not with the video

Which ones ?

You can pick up a perfectly good video splitter or the like of Ebay for less than 10 pounds that do the job just fine. They are normally of the 12 volt supply voltage range so can be powered off your ground station battery. They use very little power to operate and normally provide 4 or 5 outputs. It is super light if your wanting to keep weight to an absolute minimum. The downside to this type of splitter is making the wires tidy or keeping them from being pulled and damaged. But apart from that its really good.

A more professional and proven unit is this one, priced at under £20 typically, 12v operation, solid RCA 8 way outputs and housed in a strong ABS plastic case it is ideal for mounting on tripods and all manors of GS. It has a LED indicator for power “on” Fused DC connection wire. But no adjustment for video levels for outputs. The dots you can see on the box are not LED`s by the way. I have used this unit and still do to this day with a variety of recorders with no problems.

Variable Gain Output Splitter

An example of a variable output video splitter would be this one. It has 4 outputs all with adjustable gain pots so each one can be fine tuned to suit your equipment the best. At only £10 it is a handy piece of kit at a good price. Because it only has 4 outputs it keeps its size down to a minimum, lending itself to tripod ground stations which some of the other gain adjustable units don`t because they have 8 or more outputs and come in at some size. In reality you would be hard pressed to need 8 outputs. 4 should be just fine, 1 for your goggles, 1 for passenger goggles, 1 for an extra screen on ground station and the 4th for your flight recorder.