Advantech INTRAC-305 user manual Tracking Signal Input

INSTALLATION INTRAC-305

Selection of Southern or Northern Hemisphere within the

INTRAC is automatic based on a positive or negative input for

Latitude in System Setup - Station Co-ordinates.

TRACKING SIGNAL INPUT	The tracking signal may be provided as a dc voltage from an
	external receiver or from the optional IBR-L internal receiver.
With IBR-L	The IBR-L requires a L-band beacon signal at a level within
	the range -80dBm to -45dBm with a carrier to noise ratio
	(C/No) of better than 40dBHz. To allow some margin for
	exceptional propagation conditions we suggest that the
	normal clear sky level when peaked on the satellite should be
	in the range -70dBm to -50dBm. Severe signal fades will be
	handled by the INTRAC algorithm entering Prediction mode
	for the duration of the fade.
	If the signal is greater than -50dBm attenuation must be
	inserted and if it is lower than -80dBm a higher gain LNA/LNB
	must be used.
	An input level of -45dBm corresponds to a displayed level of
	+25dB.
Note	In some installations the LNA/LNB power is carried on the L-
	band signal cable and special arrangements have to be made
	to ensure continuity for the dc power when attenuation is
	added in this cable.
Without IBR-L	The tracking signal, provided from an external receiver, needs
	to be a dc voltage between -10v and +10v. This voltage
	should vary proportionally (in dBs) with the received signal
	strength.
	The INTRAC can be adjusted for a fixed offset and a
	proportionality constant between 0.1v/dB and 1.0v/dB in
	either polarity.
Setting offset & gain	Connect a switchable attenuator in the IF feed to the tracking
	(beacon) receiver.
	Connect the dc tracking signal to the INTRAC Signal Strength
	Input BNC.
	Remove the top cover to the INTRAC-305.
	Link J31 and potentiometers R12 & R55 are used in the set-
	up.
	Link J31 can be changed for -ve or +ve polarity signals.
	R12 adjusts the gain of the tracking signal buffer.
	R55 adjusts the offset.
	Set the switchable attenuator to 0 dB.
	Adjust R55 so that the signal level displayed on the
	INTRAC-305 is between -10dB and +20dB.
	Adjust R12 so that 2dB attenuation of the receiver IF signal
	causes the displayed signal to decrease by 2.0dB.

Page 74 INTRAC-305 MANUAL - Issue 3.2 ©2011 Advantech Wireless