© 2017 Jackson Labs Technologies, Inc.
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RSR GNSS Transcoder™ User Manual
Test Tone Modes
4.5.2 OUTput:DCBlock <ON|OFF>
This command is not supported on the RSR GNSS Transcoder™. The RF output is always
DC-coupled and has a 186 Ohms load resistor to ground to simulate an industry-standard GPS
antenna load to the target receiver.
4.5.3 OUTput:POWer?
This command sets the output power of a single GPS satellite output from the RF output. The valid
range is -105dBm to -125 dBm plus the current OUT:OFFset setting. For example if an external 10
dB attenuator is attached to the RF output and OUT:OFFset is set to -10 dB, then the valid range for
the OUTput:POWer? command is -115 to -135 dBm. Similarly, if a 10 dB amplifier is connected to
the RF output, and the OUT:OFFset is set to +10 dB then the valid range for OUTput:POWer
command is -95 to -115 dBm.
The OUT:POWer command sets the RF output power per satellite. When N satellites are
transmitting, the total RF output power is 10*log
10
N dB greater.
The nominal output power of a live GPS satellite signal at the surface of the earth is typically about
-125 dBm, but is often a few dB higher to accomodate for a reduction in power as the satellite ages.
Target GPS receivers are also often expecting an amplified antenna, so the output power is typically
set higher than -125 dBm for optimum performance of the target GPS receiver.
The format of this command is:
OUTput:POWer <power> dB
This parameter is stored in NV memory and automatically applied after power-on.
4.5.4 OUTput:OFFset?
This command sets the output power offset to compensate for an external attenuator (negative offset)
or amplifier (positive offset). The offset value compensates the value provided to the OUT:POWer
command so that the true output power from the RF signal chain including the attenuator or amplifier
Test Mode
Description
OFF
Default setting for normal GPS signal output
SWEEP
Single CW tone, swept +/- 1.023 MHz either side of 1,575.42 MHz over
approximately 30 seconds
TONE
Single CW tone at 1,575.42 MHz
TWOTONE
Two CW tones spaced approxi/- 50 kHz either side of 1,575.42
MHz. Each tone has 6dB lower amplitude than the OUT:POWER setting.
RAND
Baseband (complex) white noise generated by two independent
maximal-length shift registers with cycle times of approximately 30
minutes
Summary of Contents for RSR GNSS Transcoder
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