P.A.M.S.
Technical Documentation
NME–2A
Troubleshooting Instructions
Page 17
Original 08/97
TX Part
1. Check burst output:
Via PCLocals select local mode, RF control, TX mode, Power level 10
(23 dBm), Operation mode burst, Data type random, Continuous mode
channel 60, Channel 60, Monitoring channel 1.
Measure with spectrum analyzer on the antenna connector (40 dBm max
signal needs an external attenuator), and with scope on the power amps
control input pin 2.
– The output burst should have peak amplitude at 23 dBm ±3 dB, and
center at 902 MHz.
– If it is OK, check at higher and lower levels, up to level 2 (39 dBm) and
down to level 15 (13 dBm).
1.1. Check power tuning:
Via PCLocals select local mode, Power tuning.
– Coefficients from 0.8 at level 2 to about 0.1 at level 15.
– Tolerance of ±0.1 at level 2 to ±0.050 at level 15.
– The control signal should follow the RF amplitude with a maximum of 4
to 6 V at level 2 and 2 to 2.5 V at level 15.
1.2. TX buffer and level regulator:
Via PCLocals select local mode, RF control, TX mode, Power level 10
(23 dBm), Operation mode burst, Data type random, Continuous mode
channel 60, Channel 60, Monitoring channel 1.
Measure with spectrum analyzer on the antenna connector (40dBm max
signal needs an external attenuator), and with scope on the power amps
control input pin 2.
– If control signal goes up and RF does not follow, check with a probe
the RF input to the power amp at pin 1. It should be at 3 to 5 dBm.
– Follow the RF signal back to see if it is at the output of the balun T802.
– When measuring before the power amplifier continuous mode is pos-
sible.
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