MASTR II UHF Exciter Retuning Instructions

MASTR II UHF Exciter Re-Alignment
(Silver Handle model with high-band exciter)

The exciter metering jack is located just below T108. As with the receiver, use an analog meter (VTVM). All measurements are from the metering jack ground pin 8 or 9 to the pin called out in the alignment steps.

uhfexc.gif (37445 bytes) Measure on pin 1 and tune T103 for maximum meter reading.

Measure on pin 3 and tune T104 for a dip.

Measure on pin 4 and tune T105 for maximum, re-adjust T104 for maximum and tune T106 for a dip.

Measure on pin 7 and tune T107 for maximum, re-adjust T106 for maximum then tune T108 for a dip and T109 for maximum.

Measure from pin 5 and tune T110 for maximum and re-adjust T108 and T109 for maximum.

Measure from pin 4 of the PA metering jack and tune T111 and T112 for maximum meter reading.

Measure from pin 5 of the exciter's metering jack and re-adjust T108, T109, and T110 for maximum meter reading.

Measure form the PA's meter jack, pin 4 and re-adjust T111 and T112 for maximum meter reading.

The exciter puts out about 250 mw of RF power, adjust the ICOM frequency to the frequency of interest using a frequency counter properly connected to the exciters output. Remember, this is the alignment process for the silver handle UHF MASTR II, so the exciter's frequency output should be 1/3 of the transmit frequency. Also remember to factor in the temperature curve chart when adjusting the transmitter ICOM.