19 novembre 2016 Formation Telecom: Radio

Telecom type sum-up (early 2016) 70 bases in total:  31% Vsat => 22 bases in 9 countries (32% in 2013…)  36% DSL or Fiber optic => 25 bases including 11 capitales (33% in 2013… 14 capitales)  27% Radio internet(Wifi/Wimax/WLL) => 16 bases including 9 capitales (20% in 2013…Radio becomes better than DSL…)  50% Radio HF/VHF => 10 missions (mainly africa)  6% 3G keys => 3 bases (8% in 2013, but explode for backup use…)  0% still with BGAN => 0 bases… (7% in 2013)

19 novembre Electromagnetic wave  Photon  Caracteristics of a wave: Amplitude Frequency (Hz) Lenght (m) Speed (light speed) :

19 novembre Radio Frequencies 18 MHz Band: CW Digimode, CW IBP Phone, CW

19 novembre Waves transmission trough antennas The perfect antenna has the same physical length than the frequency we want to use (reception or transmission). In this case almost all the power of the transceiver is tranmited into electromagnetic wave. Electromagnetic wave Transmission Electromagnetic wave Tranmission If the antenna is not well choose of if there is to many obstacles, the power of the transmission is dangerously reflected into the transceiver. Reflected power

19 novembre Radio material Managing the relfected power The only feed back you have : SWR meter GOOD PERFECT DANGEROUS !

19 novembre Storm Lightning protection Lightnings can go up to volts And radio antennas are a important target. So we need to protect the radio antennas

November 19, To optimize the Radio transmission Technicaly speaking :  NEVER TOUCH THE radio ANTENNA WHILE TRANSMITING !  Position your radio antennas as hight as possible (6 meters) except for NVIS, far from any obstacle.  Take great care of the connections (grease and silicone).  Take great care of the cables (respect lenght, do not bend).  Respect the earth connection.

19 novembre 2016 HF radios

19 novembre Connecting HF Radios (ACF Doc…) : Do not forget the earth connection (half the antenna ! Double the performance... (see annexe)

19 novembre Connecting HF Radios (ACF Doc…) : Do not forget the earth connection (half the antenna ! Double the performance... (see annexe)

19 novembre To optimize the HF transmission Antenna position TopviewSideview

19 novembre 2016 VHF radios

19 novembre VHF material GP channels 136 – 174 MHz 5 watts (Tx) 8 to 14 hours autonomy Computer programming 265 euros GM340 6 channels 136 – 174 MHz 25 Watts (Tx) Computer programming About 300 euros Antenna: As high as possible

19 novembre VHF repeater Duplex TX: KHz RX: Khz Duplex TX: Khz RX: KHz Duplex TX: Khz RX: KHz In duplex mode : one frequency to transmit, another one to receive. Simplex TX-RX: KHz Simplex TX-RX: KHz In simplex mode : the same frequency to tranmit and to receive.  VHF contact is similar to visual contact  VHF reapeater can overcome the obstacles.

19 novembre  If the coverage is not sufficient (< green zone for ex), => IMPROVE THE COVERAGE VHF RADIOTESTS Material Power Altitude Range VHF Handset VHF MobileVHF BaseVHF Repeater 5 watts25 Watts About 2 metersAbout 3 metersAbout 6 metersAbout 20 meters