Daniels MT-3 Instrukcja obsługi - Strona 10
Przeglądaj online lub pobierz pdf Instrukcja obsługi dla Wzmacniacz Daniels MT-3. Daniels MT-3 20 stron. 132-174 mhz 406-470 mhz low current front end
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Front End Alignment
TU NIN G P R OC ED U R E
The best way to tune the MT-3 Front End is to use a Spectrum Analyzer with a tracking generator.
The frequency response of the Preselector Filter can be seen at the IF output. Use the following
procedure for swept frequency tuning:
1) Check to see if the correct image rejection filter is selected for the frequency
of interest. This operation requires removing the Front End's shield lid and changing
the solder jumpers if required.
2) Supply +9.5 Vdc to the MT-3 Front End (red wire).
3) Connect the Tracking Generator output with the Front End's RF input. The tracking
generator should have an output level of -20 dBm and a frequency span of at least 10 MHz.
If the preselector filter is grossly misaligned, a larger frequency span may be required.
4) Adjust the helical filter trimmer capacitors for a flat response centered at the desired
RF frequency. The measured input level should be approximately -25 dBm and the
3 dB bandwidth should be 5 MHz and 7 MHz in the VHF and UHF range respectively.
MT-3 FR ON T EN D R EM OVA L A N D I N S TA L L AT I O N
The MT-3 Front End is fastened to the main board (MT-3 Receiver IF/Audio Board) with a single
Phillips screw to the Type F connector and to the front panel with two countersunk Phillips screws.
Remove these screws and disconnect the IF, LO, and power cables to remove the VHF / UHF Front
End. Installation of the MT-3 Front End is performed in a fashion reverse to the above procedure.
MT-3 Low Current Front End Instruction Manual
IM11-FE3
Printed Copy Not Controlled