R.V.R. Elettronica TEX20-NV, Техническое руководство

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TEX20-NV Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 37
To execute this operation see as reference SETUP 1.
1) It’s advisable to start this procedure with the operating frequency
set to 87.50MHz. When locked to this frequency, the PWR ADJ control
should be adjusted for an output power of 10W.
Now, with no further adjustment of the PWR ADJ control, change the
operating frequency in steps of 4-5 MHz, ensuring that the output
power remains constant at 10W.
2) Now short circuit the central conductor of the INTERLOCK input to
ground and the output power should drop instantly to zero.
Removing the short should cause the power output to return,
gradually, to its previous level.
Deviation reading check
1) Put the selector in the DEV position.
Connect a low-distortion audio generator to the MONO and/or MPX
inputs (4-5 Fig.1A and 10 Fig.2B), as shown on the SETUP 2.
Inject a 400 Hz tone at a level of 0dBm (775mV RMS = 2.2Vpp on the
600 Ohm impedance).
Check that the deviation reading is 100% (or 75 KHz).
Connection of an External Stereophonic Source
To execute this operation see as reference SETUP3.
1) Connect the stereo source’s output to the MPX input of the unit
(5 Fig.1A or 10 Fig.2B).
2) Adjust the stereo encoder to obtain just the 19 KHz subcarrier output
(without pre-emphasis) and ensure the total absence of signals on
the left and right inputs of the encoder.
3) Adjust the output level of the encoder to obtain the correct level
(-20dB under the carrier) as displayed on the F.A.M. Modulation
Analyzer connected on the R.F. TEST -30dB of the TEX20-N.V..
4) Inject audio signals into the left and right inputs of the encoder
and adjust the sensitivity of the input to obtain a peak reading of
MAX=75KHz with both channels enabled.
SETUP 2