R.V.R. Electronica RX1-NV LCD, User Manual

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RX1-NV LCD
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USER MANUAL Rev. 1.2 - 13/12/01
•
Adjust all the trimmers so that the amplified signal reaches its maximum at the
desired frequency: you should operate on the trimmer controlling the result on the
spectrum analyzer. Trimmers 1-4 reduce the tuned frequency when turned
clockwise, while trimmer 5 shall be turned left or right depending on the case.
At the end of this operation, the signal gain should be between 28dB and
32dB.
•
Narrow the frequency span of the spectrum analyser down to +/- 500 kHz.
•
Fine-adjust the trimmers again, trying to obtain the best simmetry in the
frequency response, while keeping the gain at its maximum value. The response
shall be sensibly flat (< 1dB) in a +/- 200 kHz range around the tuning frequency.
• Reestablish the link between the input circuit and the IF circuit.
•
The RF front-end at this point can be considered tuned. Before putting in place
the receiver's covers, if you have the necessary instruments, you can measure
the stereo separation and the distortion of the receiver. If they differ from the
values described in the factory tests, very fine adjustments of the capacitance
trimmers will improve them. Note that the regulations of this step have to be
really fine, to avoid impacting the selectivity of the receiver maximized before
at the spectrum analyzer.