VCO varactors (CR201, 202, and 203) in “C” and later kits are not interchangeable with VCO varactors in earlier kits; Motorola parts and part numbers are different. When replacing a VCO varactor, Identify the transceiver board and order replacement parts from the applicable parts list.
UHF,
Since the transmit crossover frequency has changed, whenever transmit VCO crossover alignment (an RSS function) is performed, UHF band split and circuit board identification will be important.
•UHF band split can positively be determined by checking the markings on the power amplifier shield. If the power amplifier shield marking is 25U04 or 85Y10, then the transceiver is a 403 - 470MHz band split. If the power amplifier shield marking is 25U05 or 85Y11, then the transceiver is a 450 - 520MHz band split.
•The “C” kits can be identified by the circuit board number 4221J07 or 4221J37 visible on side 2 of the board, located along the circuit board edge just next to crystal filter FL1. All future UHF transceiver boards will be in the “4221J” series.
Anytime a controller board or transceiver board is replaced in a radio, it will be necessary to perform the RSS transmit VCO crossover alignment, and check the transmit VCO crossover frequency. The RSS screenforthisalignmentwillshowa“currentvalue”box 
with a frequency already assigned, placed inside the box. When performing transmit VCO crossover alignment, determine the UHF transceiver band split, and then check the transceiver circuit board number. In a UHF radio (403 - 470MHz range):
•If the board number is any “4221J” series number, other than 4221J01 thru 4221J06 or 4221J36, the transmit VCO crossover frequency in the “current value” box should be 449.500MHz. If it is not, change it to 449.500MHz.
•If the board number is 4221J01 thru 4221J06, 4221J36, or any other number not in the 4221J series, the transmit VCO crossover frequency in the “current value” box should be 438.025MHz. If it is not, change it to 438.025MHz.
VCO varactors (CR201, 203, 207, 208, and 209) in “C” and later kits are not interchangeable with VCO varactors in earlier kits; Motorola parts and part numbers are different. When replacing a VCO varactor, identify the UHF transceiver band split and the transceiver circuit board number, and then order replacement parts from the applicable parts list.
UHF,
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