MANUAL

Transmitter, Pro & Lite

Receivers, Long Range & Normal range

Rev 1.0

Rev Date. 09/03/2016

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Indhold

Foreword TSLRS ................................................................................................................................................. 3

Foreword Transmitter ....................................................................................................................................... 3

Technical Specs .................................................................................................................................................. 3

Tx700Pro ........................................................................................................................................................ 3

Tx700Lite ....................................................................................................................................................... 4

Inputs/Output connectors Tx700Pro ............................................................................................................... 4

Tx700Lite ....................................................................................................................................................... 4

Hardware specifications .................................................................................................................................... 5

Tx700Pro ........................................................................................................................................................ 5

Tx700Lite ....................................................................................................................................................... 6

TX BATTERY LIFE ............................................................................................................................................ 6

Physical Dimensions .......................................................................................................................................... 7

Tx700Pro ........................................................................................................................................................ 7

Tx700Lite ....................................................................................................................................................... 7

Legal Information .............................................................................................................................................. 7

Adapter wiring ................................................................................................................................................... 7

Binding in details ............................................................................................................................................... 8

Change unique ID code ...................................................................................................................................... 8

Tx700Pro ........................................................................................................................................................ 8

Tx700Lite ....................................................................................................................................................... 8

Output Power selection button ......................................................................................................................... 9

Tx700Pro ........................................................................................................................................................ 9

Failsafe ............................................................................................................................................................... 9

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Compatibility TX-RX ........................................................................................................................................... 9

Compatible RC's ................................................................................................................................................. 9

Head Tracker.................................................................................................................................................... 10

Tx700Pro ...................................................................................................................................................... 10

Tx700Lite ..................................................................................................................................................... 11

Compatible Head trackers ............................................................................................................................... 12

Option Board ................................................................................................................................................... 12

Tx700 Pro ..................................................................................................................................................... 12

Modem Setup Option Board ........................................................................................................................... 12

Tx700Pro ...................................................................................................................................................... 12

How to get best range ..................................................................................................................................... 13

LED indicator .................................................................................................................................................... 13

Range Check .................................................................................................................................................... 13

Known Limitations ........................................................................................................................................... 14

Foreword Receivers ......................................................................................................................................... 15

Physical and technical specifications ............................................................................................................... 15

Rx700 Normal Range ................................................................................................................................... 15

Rx700 Long Range ....................................................................................................................................... 16

Binding ............................................................................................................................................................. 17

Failsafe foreword ............................................................................................................................................. 17

The 3 Failsafe in detail ..................................................................................................................................... 17

Ch12/PPM options ........................................................................................................................................... 18

RSSI output ...................................................................................................................................................... 19

Connectors Servo............................................................................................................................................. 19

Serial Debug Output ........................................................................................................................................ 19

Special Features Configurations ...................................................................................................................... 21

Channels on Normal Range ......................................................................................................................... 22

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Antenna setup ................................................................................................................................................. 23

Bad antenna position .................................................................................................................................. 24

Firmware upgrading ........................................................................................................................................ 25

Option Board for RX LR 7.01 ............................................................................................................................ 28

LED indicators .................................................................................................................................................. 29

Abbreviations................................................................................................................................................... 30

FPV general trouble shooting guide ................................................................................................................ 33

Design hints: ................................................................................................................................................ 33

Radio Technical knowledge ............................................................................................................................. 35

Warning and Disclaimer ...................................................................................... Error! Bookmark not defined.

Foreword TSLRS

In this manual you will find guides to setup your system, tips to get most out of your system and how to

trouble shoot you problems. If you want to get a quick answer to your question you can go and see our FAQ

list, which contains all kind of questions we have received both simple and more technically oriented.

Foreword Transmitter

Here you will find the information which is needed to make your transmitter perform at the very best both

for Tx700Pro and for the Tx700Lite. Notice if the Pro or the Lite is not listed under a subject, it means that

it’s the same for both.

Technical Specs

Tx700Pro RF Output power: 500mW/1000mW/2000mW.

RF Output connector: BNC female.

The transmitter power is user selectable via easy to access 3 way switch.

(We recommend using “low” power mode, so power up is possible in case of an out of range situation will occur)

The transmitter can handle full power, continually no time limit.

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The antenna output is designed for 50 Ohm load; however the transmitter stage is specially protected and

can handle full power at both open and shorted antenna.

It is normal to perform range check with antenna removed and 500mW setting.

Tx700Lite RF Output power: 500mW

RF Output connector: SMA female

RF Input: DIN 4

The Antenna output is designed for 50 Ohm load.

The PPM input signal can be either constant frame repeat time, or variable, Positive or Negative polarisation. The special double speed Futaba PPM signal is also accepted, Auto detects and auto handle. The main PPM signal must contain from 4-12 servo channels, if main PPM signal has under 4ch it will be refused.

Note: Graupner call each way a servo travel for a channel, so in Graupner terms a 24 Channel setting

handle 12 servos, and is what we call a 12 channel signal.

Inputs/Output connectors

Tx700Pro

DIN 3 pin female screw type for POWER and MAIN-PPM input

The female DIN connector seen from outside the TX

Tx700Lite

Power input connecter

Power input connecter is centre positive

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DIN 4 pin female screw type for POWER and MAIN-PPM input

Stereo Jack for Audio Demodulator Input, and Head-Tracker PPM input

The top of the connector is Head-Tracker PPM input (shorted HT)

The Ring of the connector is AUDIO input from the wireless video system receiver.

Ground is common for both signals.

Shielded cables are recommended to avoid cross talk.

Hardware specifications

Tx700Pro

Supply voltage 5-25V for 500mW power

Supply voltage 6-25V for 500mW-1000mW-2000mW power

Supply power usage is 3 times the transmit power.

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Supply current at 20V (500mW x 3 = 1.5W / 20V = 0.075 Ampere)

Supply current at 10V (500mW x 3 = 1.5W / 10V = 0.15 Ampere)

Supply current at 6V (2000mW x 3 = 6W / 6V = 1 Ampere)

Tx700Lite

Supply voltage 5-25V for 500mW power

Supply current at 20V (500mW x 3 = 1.5W / 20V = 0.075 Ampere)

Supply current at 10V (500mW x 3 = 1.5W / 10V = 0.15 Ampere)

TX BATTERY LIFE

The TX unit draw about 1.5W as mentioned at 500mW out, to find the current it draw we use ohms law.

Examples: Watt / Supply Volt = Current, the supply voltage can be anything from 6-25V.

Example with a 3S lipo: 1.5W / 11V = 0.126A

To find the time you can run with a given battery size, take your battery mAh and divide with current usage

also in mA. Example: 1000mAh / 126mA = 7.9 hrs, remember to keep a good safe margin, some batteries

like LIPO do not like to be fully empty.

When using the power-up feature, input supply power will also go up. The unit has about 30-40%

efficiency, so an easy rule is the input usage is 3 times as much power as the output power. At 2W RF out;

the TX unit consume almost 6W, this means 4W is radiated as heat.

The TX unit can deliver 500mW out at only 5V as supply voltage; it will stop working at 3.3V or under.

For 1W and 2W output, you need supply voltage of at least 6V. Maximum is 25V!

Peak operating heat sink temperature -40C to + 80C

Suggested Operating heat sink range -20C to + 60C

PPM input, both main PPM and HT PPM, level 1.5Vpp to 10Vpp.

AC or DC coupled, this means it is also JR and Graupner student signal compatible. However for serious

stable long range flight, it is recommended to use a 3-5V DC coupled PPM signal for best stable signal to

noise margin.

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Physical Dimensions

Tx700Pro Height: 32mm

Width: 74mm

Length: 100mm

Weight: 280 gram

Tx700Lite Height: 25mm

Width: 55mm

Length: 85mm

Weight 128 gram

Legal Information

The radio system is using frequency hopping, random sequence with very short time slots. The time pr

channel is only 15mS, which means it apply to the 10mW pr average channel regulation in EU and many

other areas. This means the 500mW peak setting can be used legally without any radio amateur licence.

Note* The Tx700Lite is CE approved and certified.

Adapter wiring

Futaba

JR/Graupner

Multiplex

Naked (only for Tx700Pro)

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Binding in details

The binding function stores the TX signal unique ID code and PPM frame rate and number of servos into the

receiver; this must be done every time the number of servos is changed on the RC unit. (or another RC with

PPM system)

The binding process is the same on Tx700Lite.

To bind:

1. Power off, Tx and Rx.

2. Hold down bind button on Tx.

3. Power up the Tx, (we assume right plane memory is recalled on your RC unit).

4. Power up receiver, make sure both antennas are connected and within 20 meter / 65 feet distance.

5. Wait 1-2 sec, see the RX LEDs go from lit into fast blink mode.

6. Power off Tx (Rx is still on).

7. Power on Tx (Rx is still on).

8. Test all servo functions on plane works and have ultra fast and smooth response.

9. With TX on, try to power OFF and ON the Rx and prove it lock to the Tx very fast after power on.

Instruction video on how to bind and store failsafe - http://www.youtube.com/channel/UCS2wXoorQHQaYmoSLE5_esg

If you use external battery for the LRS TX, then the binding procedure is a little bit different, leave the RC

unit on ALL the time and connected to the LRS TX, the power on/off to the TX as mentioned in the binding

procedure is only the LRS TX, now it will work, the binding mode is only activated when button is held down

while power to the LRS TX is applied.

Change unique ID code

Tx700Pro Remove the top lit, inside the TX unit you find a DIP switch with 8 tiny white buttons, which can be slide up

or down.

Tx700Lite

Remove the top lid with the bind button and led. Now pull the board out slowly from the other end. Inside

the Tx unit you find a DIP switch with 8 tiny white buttons which can slide up or down.

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Note: The text ID code next to it. If you need to create a take-over mission, then the two TX units must have

the same ID code to be accepted by the RX. If you need to fly side by side with a friend, just be sure you use

different ID code. After ID code change, a new bind must be performed.

Output Power selection button

Tx700Pro The 3 way transmit power switch is located near the antenna connector on the top, where it is most easy to

access while in flight. Move the connector close to the antenna connector for low power mode. It is

recommend to use as little as possible power, so power-up is possible in case an out of range situation is

experienced, this way it is possible to regain control and fly back home.

Failsafe

The same push button on the top is used both for binding, and to store Failsafe into the receiver.

When the button is pressed while the TX is powered on it’s in the binding process.

When the TX is in normal flight mode, the button is used to store failsafe.

The failsafe procedure is explained on page 18.

Compatibility TX-RX

All versions of TSLRS RX units can be binded and work together with any versions of TSLRS TX units.

Since the over air signals are kept the same from the very start. The TSLRS system parts is NOT TX-RX

compatible with any other brands of long range systems, we all use our own radio modulation system.

Compatible RC's

Any Radio Control remote system with PPM output should be able to used, check your manual for student

out, and if it is compatible with PC simulators and other types of RC systems, then you know you got a PPM

signal and not a special un-compatible digital signal. The PPM signal can be any polarity, and also variable

speed, and even the special Futaba double speed mode is supported. See our RC compatible chart to

secure that your RC works.

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Head Tracker

The Head tracker input must be 6 channels PPM. It accepts positive or negative polarization, variable or

fixed frame rate auto detect and auto handle. Channel 5 and 6 are the two HT (PAN/TILT) signals. They are

added after the used MAIN-PPM channels. In case the main PPM signal got 12channels in it, there are no

free channels to use. Then the two HT signals will be merged into channel 10 and 11, leaving channel 12

free to use for the main PPM. The reason for this is easy to understand, look at the receivers: the channel

12 connector can be either PPM out or servo channel 12 out, the different output mode is configured on

the RX, in case you need PPM out and use a HT at the same time, you need off course the HT signals to be

on ch. 10-11 where normal servo connectors exist.

Tx700Pro The head tracker input is integrated in the Tx700Pro

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Tx700Lite With the Tx700Lite – the head tracker input is integrated in the cable

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Compatible Head trackers

The Fat Shark, M.I.G. Tracker, Magnetic Inertial Gyro

Or any other type with the required signals, see Head Tracker section above.

Option Board

Tx700 Pro The extra add on board called Option-Board can be installed by the user.

The extra features are:

Firmware upgrade via USB connector.

Both the TX main board, and the Option board CPU can be upgraded with this option board.

Data Demodulator and PC USB interface, for UAV systems. (live 2 way data is then possible)

Voltage monitor with audio alarm.

THIS SECTION WILL BE UPDATED WHEN THE OPTION BOARD IS RELEASED.

Modem Setup Option Board

Tx700Pro The Audio signal is 1200 Baud FSK from a video receiver, the level can be from 200mV to 2000mV

adjustable on the upgrade board trimmer, adjust trimmer for carrier LED LIT, find the two points where the

LED is not lit, and set it in the middle of that for best margin to both sides. Install FTDI232 VCD driver on the

PC, run your UAV control software to display live flight parameters.

THIS SECTION WILL BE UPDATED WHEN THE OPTION BOARD IS RELEASED.

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How to get best range

Archived range is only the result of the wanted signal to noise ratio. Local noise emitters are the most

common way to ruin good receiver’s capabilities to pick up weak signals at long range. The system got a

transmitter to receiver calculated line of sight range of over 100km. We know at least one customer who

actually performed a full flight over 100km out and back. To be able to get the full possible range this

system can deliver, you need to be very sure nothing on your plane emit noise in the used frequency band,

if it does it will affect the range. This means also it is very easy to detect using range checks.

LED indicator

Constant light = PPM ok, power supply ok

Blinking LED = Power supply ok, but no valid PPM

No Light = No power supply voltage

Range Check

Can be done just like any conventional RC systems and please follow the following steps:

1. Unmount the TX antenna and set it to low power.

2. Expect 4-10 meters of range.

3. Check you have same (short) range with motor on/off and with video cams and video transmitters

on/off.

4. If no change in the range result, then mount TX antenna again and fly.

5. If any unit on your plane affect your range, you are supposed to seek and fix it, if you want to take

full advantage of the systems capabilities, or at least obtain a system with best possible signal to

noise margin.

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Known Limitations

Landscape variations and noise pollution in the flight area is known to shorten the range of any wireless

link. Use at least 1/10 of the distance as height. For example at 3 km/1.8mile, distance stays 300

meters/984 feet up, to get full range.

The Tx700Pro with will provide you with a signal to 100km/62 miles range depending on power selection

and on which receiver is used.

This Tx700Lite with 500mW will provide you with a signal to 25 km/15.5 miles range depending on which

receiver is used.

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Foreword Receivers

Here you will find the information which is needed to make your receiver perform at the very best. Both

the long range receivers and normal range receivers will be listed under each subject.

Physical and technical specifications

Rx700 Normal Range The receiver board: 26 x 54mm.

Weight: 6.5 gr. (8.5 grams including wire)

Sensitivity: -102dBm.

Input supply voltage range: 4-10V.

Servo signal pulse output: 3.3V positive.

Radio band: 433 & 444 MHz multi band and multi frequency hopping system.

Temperature range: -40C to +70C tested.

Receiver 8ch - optimized input filter so it can co-exist with strong 2.4 GHz on board video transmitters.

Wire antenna mounted directly on the Rx.

The extra pin in ch 12 connector is RSSI out. Ch 12 connector is also PPM out when < 12ch are used.

PPM out is the same as sum-signal and this is of course fully compatible with MikroKopter controller board,

all RX have this SUM and RSSI out.

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Rx700 Long Range This receiver have improved input filter and makes it now even better attenuation for 900 - 1300 - 2400

video transmitters. This is virtually impossible to jam. The Rx700LR also have improved distance of the

servo connector and now all 12 can be mounted at the same time and no bending or problems.

The receiver have the following dimensions:

Width: 34 mm.

Length: 62 mm. including angled connector.

Height: 10 mm.

Weight: 16 gr.

The receiver uses a Double LNA (Low Noise Amplifier) frontend with fast signal switch so it uses the best

signal.

Two MCX connector coax dipole wire antennas come with each RX t – Weight: 5.4 grams each.

The extra pin in ch 12 connector is RSSI out. It’s now buffered so loading of the RSSI out is uncritical, 1k

ohm Zout. It is also filtered to avoid less jumpy OSD readings.

CH 12 connector is also PPM out when < 12ch are used (auto mode is the default).

PPM out is the same as sum-signal and this is off course fully compatible with MikroKopter controller board

and all RX types and models have this.

Sensitivity: -113dBm to -114dBm

Input supply voltage range: 4-6V (Rx uses 134mA at 5V)

Servo signal pulse output: 3.3V positive

Radio band: 433 & 444Mhz multi band and multi frequency hopping system.

Temperature range: -40C to +70C tested

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Binding

The binding function stores the Tx signal unique ID code and PPM frame rate and number of servos into the

receiver; this must be done every time the number of servos is changed on the RC unit. (or another RC with

PPM system). The binding procedure is explained on page 8.

Failsafe foreword

The push button on the top of the TX is used both for binding, and to store Failsafe into the receiver.

When the button is pressed while the TX is powered on the unit is binding. When the TX is in normal flight

mode, the button is used to store failsafe.

The different modes of failsafe in the receiver manual are:

The “Normal”

The “Sequential”

The “None” All kinds of FAILSAFE storing and testing should be carefully performed with the plane firmly grounded.

It’s normally good use full failsafe style to program the plane to shut of motor and turn slowly to the left

side. Some FPV/UAV systems can use other settings; the user should know what is best for his usage.

Always test if it’s working as expected before a flight – Test if recall the wanted function and recover again

when the TX is powered back on.

The 3 Failsafe in detail

The normal kind of failsafe is one set of servo positions stored in the receiver. This setting will be recalled

and used when the radio signal is lost for about 1 second. To store a set of servo positions, push and hold

the button for 1 second and then release it. Please be sure not to push it again the next 5 seconds.

The “Sequential” works almost the same way. The difference is that you push the button again under 5 sec

after release to store the next set of servo positions. This can be repeated 3 times to use all 3 servo

memories. They are recalled in same order as stored, and when/if the radio signal is recovered the return

to normal flight is the reverse way.

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The procedure is as follows:

The radio signal is lost - recall 1, recall 2, recall 3. Radio signal back, - recall 2, recall 1, live.

It will run scan mode which means, if a good package is received while it is in recall 2 state, it will go directly

to recall 1 and then back live. Each recall state take about 0.3 seconds then it recall the next state. This

special kind of failsafe can be used to handle special features on some multi rotor flight controller boards to

activate the RTH or safe landing procedures, depending on how you moved your switches while you stored

the fail safes.

The “None” is when the receiver doesn’t have any positions stored at all. In this way nothing will be

recalled and it will simply hold last known good position of all servos. To clear the failsafe memory, hold the

button for 5 sec.

A little side note on failsafe storing. The Receiver will lose radio link and recall failsafe settings while you

activate a storing. The reason is the kind of memory used for this is a bit slow and while the CPU waits for

the saving it’s not able to maintain a perfect hoping sequence. This is perfectly normal but it is not normally

seen when you only store one set of positions, since the values you recall while you hit save are mostly the

same as your active positions.

Ch12/PPM options

The signal CH12/PPM - If you use under 12ch you will always get PPM out of the ch12 connector. However

if you need PPM out and use 12 channels then you simply configure it to be in PPM OUT (See special

features configurations for guidelines how to do this).

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RSSI output

The little extra PAD over the CH12 connector is the RSSI output and you the bottom pin row for ground.

This is an analogue voltage that reveals how strong the signal is from the TX. Many OSD types can use this

voltage to display a calibrated 0-100% readout on the screen display. The Min and Max voltages are a little

bit different from RX to RX, so you must perform a new calibration if you swap a receiver in your system.

Connectors Servo

Look carefully at the connector pins and the PCB. The edge rows are all GROUND, the centre row are +5V

and all top pins are the servo channels out.

Serial Debug Output

The upgrade connector pin out

1 = GROUND (2, 3, 6 are not connected)

4 = Radio data (do not connect anything to this pin in flight mode)

5 = Debug data output

The debug out is a 3.3V serial signal, can be used for OSD or onboard flight recorders,

The data format is very simple, 9600 Baud 8N1.

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The data you get are:

G: number of Good data packages received

B: number of Bad data packages received

F: number of Failsafe recalled

Values are counted from RX power up and will be zeroed again at next power up, so it is possible to land,

connect to a PC via serial port converter and see the values for the flight before you power off the RX.

The serial debug can also be use full to test failsafe storing and recalling, it write in clear text what it is

doing. And it is also active during power up and under special mode setting configurations.

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Special Features Configurations

The receiver can be configured to do a few things other than normal.

HOW to configure (if you don’t need to configure, just power it up as normal)

POWER OFF

connect a 2.54mm 2 pin jumper (a short circuit connection)

on servo channel 6-7 (YES between the two signals, they are now shorted together)

Power up the RX

See LED D1 is lit, this one is closest to same side as ch6

Now you stored a permanent setting: PPM out even if you use 12channels.

Power off, Remove jumper, Connect your servos, Test all works.

POWER OFF

Connect a 2.54mm 2 pin jumper (a short circuit connection)

on servo channel 7-8 (YES between the two signals, they are now shorted together)

Power up the RX

See LED D2 is lit, this one is closest to same side as ch8

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Now you stored a permanent setting: servo ch 12 out, if you use 12channels.

Power off, Remove jumper, Connect your servos, Test all works.

if you use under 12ch, you will off course always get PPM out of the ch12 connector,

after a setting change, or PPM timing change or number of channels assigned, you must always perform a

bind, and store failsafe, and test all settings works.

Channels on Normal Range

Notice a channel 9 and 10 on the board if you wish to get more of you receiver. Connect your power and

ground to one of the other channels pins and then solder the servo control to the 9 or 10 channel pad.

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Antenna setup

The ground wire must be separated a bit from the coax. There are no rules of how much of a distance, but

3-5 cm is normally used.

RX antennas always have to mount with a 90 degree from each other. With this setup there will be no lost

spots. See this example with an airplane. - The antennas are the red lines.

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Bad antenna position

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Firmware upgrading

Use the 6 pin female connector it is clearly marked with UPGRADE or FIRMWARE UPGRADE, note the arrow to pin 1 and also the upgrade text is also located closest to pin 1. Actually any USB interface with FTDI232 chipset can be used - the Arduino boot loader type or our own called TSLRS-USB. They both fit directly into this 6 pin row.

First install FTDI virtual com port driver http://www.ftdichip.com/Drivers/VCP.htm

Then download mcuboot original version (some users might find version 1.3 works better if win7 or win8) http://webx.dk/rc/uhf-link3/mcuboot.e_x_e

If this version don’t work with your version operating system, please try this mcuboot version 1.3 http://webx.dk/rc/uhf-link3/mcuboot13.e_x_e

Rename e_x_e extension to exe, this mcuboot.exe is made using Borland some PC's might need some DLL files, in that case you will be notified, about their names, if so, ask support, or google after them.

Select right comport - check your virtual comport number is right if you use USB, click OK

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Browse to the HEX file you got via email, using OPEN.

Remember the TX hex is for TX unit, and the RX hex is for the RX.

File is accepted and loaded, pull down in window so you can see the black status area, click CONNECT

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Mcuboot now instruct you to cycle power supply, they means actually you POWER UP RX or TX unit NOW

Now you should be connected to the "secret" boot loader program

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Click Program and see on screen and status area checksum bytes

After 7 sec your unit is upgraded. The Boot loader will exit and mcuboot will say Programming done, now

check firmware is working and new features work as expected. You MUST read about the features of your

new software so you know how to use it. You must expect to perform new bind and new store failsafe after

an upgrade.

Option Board for RX LR 7.01

The option board contains a data modulator, so live flight data from the OSD is modulated into audio that is

then transferred to ground station via the video links audio channel. This option board is ONLY compatible

with RX LR 7.01 and up.

THIS SECTION WILL BE UPDATED WHEN THE OPTION BOARD IS RELEASED.

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LED indicators

The NR got one LED it simply indicates valid supply voltage.

The LR got two LED’s one located near each antenna connector.

The normal operation of the LED’s are during flight and installation to show what antenna signal is the

strongest, since that is the selected signal.

FAST Blinking LED during power up indicate search mode.

FAST Blinking LED during flight indicates failsafe is recalled and search mode is now running.

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Abbreviations

Names often used on UHF LRS pages and when talking about radio control and video links and FPV.

RC - Radio Control, remote wireless control of something

RC unit - The radio control unit you hold in your hand, can be a Futaba, JR, Graupner, Multiplex and so on

Servo - when connected to rudders/ailerons/elevator they steer a plane.

Servo pulse - is a digital pulse width that hold position information, 1.5mS is centre position.

LRS - Long Range System, often a short for my system, sometimes also called UHF LRS

UHF - Ultra Height Frequencies, is 300-3000MHz, but radio amateurs often call UHF = 70CM band, also

known as the 430-470MHz area

TX - Transmitter used to transfer a signal to a receiver

RX - Receiver used to receive the radio signal and output the signals, pulses, audio, video, data

RC RX - Radio control receiver, can be any type any brand and any coding system, they all output standard

servo pulses

LRS TX - the metal box containing the 500mW transmitter used for my long range system.

LRS RX - the receiver located in the plane, this receiver is connected directly to servos and 5V supply

RSSI - received signal strength indication, is often an analogue voltage that goes up or down depending of

radio signal level in a receiver

Video TX - Video transmitter, located on a plane, car, boat, helicopter or whatever, often using 900-1300-

2400MHz

Video RX - Video receiver, located on ground, when connected to a TV screen you can see live pictures

from the Video TX

Video Splitter - is an amplifier that will allow the user to distribute a video signal to several things at the

same time.

PPM - Pulse Period Modulation, is the pulse system used in trainer/student systems, it contain high

resolution information’s on all servo positions assigned.

PPM inverted - the pulse can be normal or inverted, some older systems do not handle both when

connected as student/trainer

LOS - Line Of Sight, is the distance from ground to a plane with nothing in the way, not even ground.

Long Range - is normally not defined, but when a plane is not visible by direct sight it is normally called long

range

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BNC - is the connector name/type used for the TX and Booster for my LRS, same connector is used on

Ethernet systems.

Booster - is an amplifier that will take radio signals and boost them up to a more powerful level.

LNA - Low Noise Amplifier is used in receivers as the front end stage, they improve the sensitivity and

therefore also the range

Diversity - is often a double antenna and/or double receiver system with auto switching to the best signal,

this improves the useable range allot

GPS - often we use a GPS receiver on planes to feed speed, position, and height information to OSD

systems.

OSD - On Screen Display, will overlay interesting information to a live video signal.

Logger - will record data or measurements for playback / view later, some OSD systems can log some

information’s too.

Modem - Modulator Demodulator, encode data into sound, and back again, can use audio line in a wireless

video system to transfer data like GPS positions

Head Tracker - a unit mounted on a person’s head, will then control remote located servos so a remote

camera follow head movements, gives Virtual Reality experience to FPV.

FPV - First Person View, like pilot view out the front window.

UAV - Unmanned Aerial Vehicle, a UAV is a fully computer guided plane, not a radio controlled plane,

if RC'ed it is an FPV or just a normal RC plane

Trainer - Most advanced RC units have trainer connectors with PPM in/out so they can be connected via a

cable to a student RC unit.

Student - Most advanced RC units have trainer connectors that can be configured to output PPM signals for

a PC simulator or trainer RC unit or LRS.

Patch - A patch antenna is a directional antenna that will when pointed to a plane improve the range

Yagi - A Yagi antenna is a directional antenna that will when pointed to a plane improve the range

Dish - A Dish antenna is a directional antenna with highest possible gain, will when pointed to a plane

improve the range

Gain - antenna gain is often named in db, more db more gain, and also a more narrow beam, so pointing

correctly is harder with high gain.

RF - Radio Frequency, any frequency that is not directly hear able audio

RF module - often a plug in box or module or printed circuit board that can be changed/added in RC units,

normally a transmitter

BEC - Battery Eliminator Circuit, is a 5V-6V regulator often linear type that makes supply for RC RX and

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servos

SBEC - Switching Battery Eliminator Circuit, is a 5V-6V regulator switch mode type handles more input

voltage and have lower loss

RC Receiver Battery or Supply, is normally 4 or 5 NIMH cells providing 4.8 or 6V of steady and stable

supply, such a battery must be able to handle

all servo max currents and still provide sufficient stable voltage, do not use spring loaded battery cassettes

or weak current capable cells like normal alkaline types,

Today more new and fancy battery types like lipo and lion and such can also be used if receiver

and servos can handle the different voltage range they provide.

Fading - when the distance and positions and angles of a wireless system is changed the radio signal will

also change

Multipath Fading - A direct signal and a reflected signal hit receiver antenna with -180 deg phase, creating

a zero signal level

Nulling - is the same as Multipath fading

FHSS - Frequency Hopping Spread Spectrum, a way to send data using many different frequencies, makes a

system immune to noise and jamming proof.

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FPV general trouble shooting guide

Read this first and try some of this before asking around.

Any FPV system car or plane or helicopter or whatever is often a compact system, containing:

transmitters, receivers, sensors, hi power pulsed electrical, vibrations, microcontroller electronic boards,

video camera, switch mode supply too be able to combine all this into a tiny lightweight platform is a huge

challenge and to make all units perform perfectly without interfering each other is often an almost

impossible task, even for skilled electronic educated persons.

Design hints:

Plane size small planes are cheap and easy to transport, but they are not optimal FPV platforms. The

smaller type the more compromised performance you must expect to get.

Receivers must be located as far away from transmitters as possible, at least a distance that can prove no

degrade of the receiver system range when the Tx is operating or not.

It is advised to keep receivers away from all electronics, in general, speed controllers and switch mode

supplies are known to be able to jam.

Electric Motor controller a range check must prove no degrade/change when motor is off, halve, full

power, this also apply for gasoline and methanol engines

Transmitters for live video or data back telemetry will always have harmonics, like 2x 3x and so on of their

wanted frequency the level might be low and under demanded levels, but when located near a receiver

that may operate on a x2 or x 3 frequency it is doomed to fail! Plan your frequency bands to avoid using

any channel at the exact harmonic of any other system you use.

GPS are often small module receivers, designed to be cheap and just cheap!! That is what we like, but

cheap come with a problem price. They are not designed to be working near transmitters; some cannot

handle anything not even if it is even GHZ away!! so a SAW front end is a must and a good high level

capable front end is a must too, and even then some GPS modules do not like to be located near 900 or

1300MHz video transmitters first harmonic of 900MHz is 1800Mhz, a GPS works at 1575MHz its front end

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system is often several hundred MHz wide, even if they have a SAW, so 1300 and 1800 can jam it.

a 2.4GHz video transmitter have first harmonic at 4.8GHz so it is no big problem with the harmonics,

it is a known fact that most 2.4Ghz video transmitters are most likely better with most GPS units.

Video stripes is often seen when a power supply is not clean or ground / signal wires are shared with

power or other units on the plane, note if the stripes are constant or change with motors or servos or other

items moving or operation, try to touch camera or video transmitter, see if any change in the stripes.

Grounding items with analogue signals specially video signals are super sensitive to grounding problems

you cannot supply a pulsing current on a ground wire to a video connected device, if this ground wire is the

same for video signal, it is quite difficult to explain how to split signal ground with power ground. A “Star”

kind of grounding has a zero current / zero voltage in the centre point.

Power supply cleanness. Try to mount external battery on different items they are super clean, and is

smart to try locate a problem.

Switch mode, it is often seen SBEC or other switch mode regulators are designed to be cheap and have no

really good filter, extra 100uH coils and 470-1000uF on the input and output might help, input is just as

important as the output.

Shielding some devices radiate magnetic pulses, specially SBEC and cameras, if they are contained in a

closed metal case the problem will be less, but weight will go up, iron cases are better for low frequency

magnetic problems.

Camera some types radiate radio noise, uncased types are the worst! but cased types can also do it, case is

maybe painted and therefore not fully shielded, the wires from it works like radiating antennas, ferrite

torrid and aluminum-foil is a good solution, and distance to GPS and other receivers is a good idea tool.

Servos some RC servos types are only designed to be used near receivers, clear enough, but when located

near a transmitter they can be jammed, moved or stopped or other weird things even periodic problems

have been seen. Tricks/solutions: aluminium-foil around the servo, wire turned on ferrite torrid.

Electrical motors are also inside servos they will also radiate magnetic pulses when they move.

Some systems like video transmitters and cameras and osd systems do not like to be near this field.

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Vibrations is a normal problem for receivers and transmitters, their coils and crystals and filters have

microphone behaviour, pack in foam and also avoid loud sound

SWR a video transmitter with a badly matched antenna and/or badly grounded will have high frequency

currents going on its signal and power cables.

When having range or interference problems, try to isolate different items, like turn it off, or change their

position dramatically or bypass its function until you find a change in your problem, then you have found

the noisy item.

Radio Technical knowledge

Any wireless radio system contain of a transmitter side antenna and a receiver side antenna.

Both sides must have same polarization to perform most optimal, the most common polarizations are

horizontal, vertical, circular left or right.

If a horizontal is “talking” to a vertical, the link loss will have an added extra loss of 26dB

If a circular left is “talking” to a circular right, the link loss will have an added extra loss of 26dB

If a circular left is “talking” to a vertical or horizontal, the link loss will have an added extra loss of 3dB

This is why it is smart to combine a horizontal or vertical often mounted in a plane, with a circular receiver

on the ground, then the 26dB drop can most likely be avoided.

Pointing a whip style antenna to a plane is the worst thing you can do, imagine looking into the end of the

whip, It is almost impossible to see from a distance, radio waves work this way too, make antenna most

visible and right polarization.

It is normal that radio links have a 26dB extra margin in its link budget / range calculation so you don’t lose

contact - when one antenna is rotated unlucky angle, a diversity system can take full advantage of its link

budget, so the resulting useable range is almost 10 times as much as a non diversity system, if no other

parameters are changed.

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A downlink diversity system also solves one other problem, fading and nulling, the most perfect diversity

system would have 3 antennas to handle signals from any angle perfect, but the gain from doing this is

often minimal and cost and complexity is big, a 2 antenna diversity is the most common compromise.

All cellular systems use diversity on the receiver side and brute transmitter power on the Tx side to perfect

the link, a cell side Tx is over 26dB more power full over the handset transmitter to obtain an equal quality

link, also handset side have a cheaper receiver with less sensitivity, we do not have space for a diversity

antenna system on a cell phone.

Wavelength and frequency - a double frequency will have halve the wavelength. Long wavelength cannot

pass thru small holes, like take a 27MHz walkie-talkie and try to use it inside two cars, (cars are made of

metal, end the window holes are much under the wavelength) the useable range is then really bad, now go

out of the cars and see you get 10 times the range, at higher frequencies you don’t have the car window

problem, but air attenuation is higher with higher frequencies, so a longer range is easier to get using lower

frequencies.

Gain - Adding more antenna gain will only make the beam more narrow, point the antenna right and you

get more range, point the antenna wrong and you lose signal, Any gain over 8-10dB will be hard to point to

a moving target like a plane, you need a tracker system or a cheap friend that will work for free to point the

antenna.

An 18dB gain yagi antenna on the receiver side and 500mW 2.4GHz video transmitter with 0dB antenna,

have a proven LOS of 51km when both polarizations are right.

Range and dB - Improving a systems link budget with 10dB will increase the range by a 3 times factor, 10dB

power is the same as 10 times the power.

20dB more power gives 6 times the range, 100 times more power, combining more power with more gain

is often the way to get longer range, and also improving receiver side sensitivity is a good way to go.

Bandwidth vs. range - Video transmitters with audio, stereo and mono exist, the video signal is 5MHz wide,

and the audio is 5KHz wide, A factor 1000 in bandwidth, so in theory the same range will be achieved on

the audio as the video link with only 1/1000 of the power, that is why those systems have a much lower

power in the audio, often see -20dBc to -30dBc, dBc means dB under the main Carrier -30dBc is the same as

1/1000.