TrueRC Canada

Thomas Scherrer's LRS

Instructions

This RC control system is specially designed for RC model planes that need extreamly long range and safety, like: FPV/UAV, large models, and expensive models.
The TX unit samples PPM frames from a normal RC TX unit, with up to 4-12 servo information's, and encode this digitally with a complicated checksum,
the receiver part decode it and generate up to 12 servo pulses, this gives a jitter free system known from all PCM systems.
at the same time this system uses a complex wide band multi frequency hopping (FHSS), makes it virtually imune to jamming,
the ultra fast diversity antenna switching system removes all dark-holes when the angle of the plane to the transmitter changes.

In many contries frequencies in the 433, 434MHz and 444 MHz band have been legally assigned to be used for RC control of models.
it is legal to own and use transmitters with up to 500mW without any license or approval.

Transmitter board inside the case, NEW version 4.00 released Dec 15 2009

The transmitter board is 45x68mm. Now using 4 layer special burried via PCB for better cooling, mounting and grounding
Possibility for more output power: constantly if needed, improved
Safety ! fly using the low power setting, and in case loss of signal activate the powerup feature
The unit is shipped with a 3 way switch so the user can fast and easy change the level while flying
0.5W / 1W / 2W power out, the 2W setting can now be used as long as you like.
RF Power output: 0.5W or 1W or 2W use selectable
Supply Voltage : 6-25V using internal switchmode converter improved power handeling
Supply current : depends on input voltage, input supply power is 3-4 times of RF output power
Spurs : 60dB and 80dB under carrier, improved new double low pass filter
Temperature range: -40C to +70C tested

Receiver 4.02 LR Long Range Diversity, (The current version of february 2010)

Improved input filter, now even better attenuation for 900 - 1300 - 2400 video transmitters, virtually impossible to jamm.
The receiver board is 34 mm width, 53mm long, (8mm longer when angled connector option as shown) 12mm height, weight: 19.4 gr.
Receiver 12ch with DIVERSITY ! and LNA Low Noise Amplifier, uptimized input filter so it can co-exist with strong 2.4Ghz on board video transmitters.
Two MCX connector coax dipole wire antennas come with each RX this type, weight 5.4 gr each.
The extra pin in ch 12 connector is rssi out, it is 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
PPM out is the same as sum-signal and this is offcourse fully compatible with mikrocopter controller board, all RX types and models have this.
Sensitivity: -113dBm to -114dBm IMPROVED NEW LNA with less noise factor
Input 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

Here is the NEW PA Booster version 4 with improved and bigger heatsink, and a few new features

NEW FEATURES of V4: added safety and security
Auto power on from 50mW input it will power up
if no RF signal input it will idle at zero current, so it can now be left powered on all day long
LED indicator one dual color, red-green
Green lit constantly = all is perfect, RF level in is fine, and DC supply is fine
Green off blinks start at 150mW and down to 50mW, longer and longer off time = less input power
Red blinks show input voltage is under 6.8V
longer and longer RED lit time when voltage drops more.
Green and Red blinks can be active at the same time in case both low rf level and low voltage
booster still works at different voltages, and can now be powered as low as 2-3V

The booster will give good power from 125mW to 500mW input
500mW is nominal input, 125mW is -6dB accepted max cable loss, at this point output will drop 1db
input will survive 1W for 10 sec, and 2W for 2 sec, maybe more but I did not dare to test the kill time

The previous booster versions had idle currents in the 400-600mA range, so booster could not be left powered on when not flying
risk of using all battery power existed. Users with V3.x boosters must be aware of this.
Idle current is defined as the current the booster draw with no RF input

Idle current for booster V4 is only 1.4 mA !

This tiny PA booster is designed to get 500mW input from the V3 RC system
Boosting 0.5W to 7W will increase the range by at least a factor 3 !
The PA module consume about 2A at 7.2V and give 7 to 8 Watt out of pure long distance RF power

Booster Specifications Version 4 at 500mW input
Vin, Current in, RF Power Out, Efficiency:
9.0V 2.58A 9.12W 39% DO NOT GIVE UNIT OVER 8V
8.5V 2.50A 8.71W 41% DO NOT GIVE UNIT OVER 8V
8.0V 2.42A 8.51W 44% MAX recommended supply voltage
7.5V 2.32A 7.94W 45%
7.0V 2.22A 6.92W 44%
6.5V 2.12A 5.89W 43%
6.0V 2.00A 4.00W 33%
5.5V 1.90A 2.95W 28%
5.0V 1.78A 1.74W 19%
4.5V 1.67A 1.35W 18%
4.0V 1.55A 1.12W 18%
3.5V 1.40A 851mW
3.0V 1.03A 589mW
2.5V 613mA 245mW
2.0V 180mA 11mW

So it is possible to change RF power by simply using powersupply voltage adjust.
a 6 cell NIMH battery and a rotary switch (brake before make) can be used.

RF cable
The BNC - BNC cable you need to use from standard 500mW tx unit to your booster (is not supplied)
use any 50 ohm impedance cable with loss from 0dB to 6dB at 500MHz.
network cables with BNC 10base-2 are 50 ohm, cheap and available world wide.
Different cable types have different loss, here is the max length allowed using different cables:
RG-58CU 18meters (59ft)
RG-223 17meters (55ft)
RG213U 37meters (121ft)
Ecoflex10 67meters (219ft)

install and use
It is recommended to place this booster with antenna as far away from ground station video receivers
as needed, to achive full video range ! this must be checked with booster on/off.
mount booster with antenna as hight and free as possible to achive as good range as possible.
Directional antennas will give you futher range, a gain of 10dB = 3 x the range !
ham radio beam antennas for the 70cm band are cheap and easy to get worldwide.

Temperature Check your booster is not running too hot, a heatsink temperature of 50C (122F) is maximum allowed !
50C is arround that temperature it is impossible to touch the heatsink for 3sec !

WARNING:
Power supply MAX is 8.4V, max supply current 2.5A, newer ever exceed that.
Use 6 cell NIMH battery or 2 series LIPO cell.
Do NOT reverse voltage polarity, a fuse inside the Booster wil blow if reversed and if lucky the amplifier is possible to repair cheap
Do NOT opperate this PA without output antenna connected.