242-984x-2xx (UHF) Part No. 242-988x-2xx (800 MHz) Part No. 242-989x-2xx (900 MHz) Copyright © 2001 by the E.F. Johnson Company The E.F. Johnson Company, which was founded in 1923, provides wireless communication systems solutions for public safety, government, and commercial customers. The company designs, manufactures, and markets conventional and trunked radio systems, mobile and portable subscriber radios, repeaters, and Project 25 digital radio products. Viking Head/EFJohnson logo, LTR®, LT

The microcontroller also monitors power amplifier ambient temperature and voltage and cuts back power or disables the transmitter if either are excessive. 3.2 POWER DISTRIBUTION AND SWITCHING 3.2.1 POWER SWITCHING CONTROL A diagram of the power distribution and switching circuits is shown in Figure 3-1. The main power switching is performed on the RF board by Q510 and other transistors. This switch is controlled by the front panel power switch, the ignition sense input, and the microcontroller a

MOBILE RADIO OPERATING MANUAL SAFETY INFORMATION Proper operation of this radio will result in user exposure below the Occupational Safety and Health Act and Federal Communication Commission limits. WARNING DO NOT allow the antenna to come close to, or touch, the eyes, face, or any exposed body parts while the radio is transmitting. DO NOT operate the radio near electrical blasting caps or in an explosive atmosphere. DO NOT operate the radio unless all the radio frequency connectors are secure a

It is matched to the 50 ohms by several capacitors and sections of microstrip on the input. Class C self bias is provided by L608 and ferrite bead EP603. From Q600 the signal is fed to final amplifier Q601 which is similar in design to Q600. Each stage has a gain of approximately 5 dB, resulting in an output power from Q601 of approximately 55 watts. The supply voltage to these stages is the unswitched battery supply. Therefore, power is applied even when transceiver power is turned off. Two RF

Q 007 NPN general purpose 576-0003-658 Q 100 NPN UHF low noise 576-0003-651 R 001 Pot 50k ohm w/push-on sw 562-0018-075 R 002 22 ohm ±10% 2W wire-wound 569-2004-220 R 003 47k ohm ±5% 1/8W smd 569-0105-473 R 004 47k ohm ±5% 1/8W smd 569-0105-473 R 005 47k ohm ±5% 1/8W smd 569-0105-473 R 006 47k ohm ±5% 1/8W smd 569-0105-473 R 007 47k ohm ±5% 1/8W smd 569-0105-473 R 008 47k ohm ±5% 1/8W smd 569-0105-473 R 009 47k ohm ±5% 1/8W smd 569-0105-473 R 010 10k ohm ±5% 1/8W smd 569-0105-103 R 011 10k ohm ±

001-9800-001 PARTS LIST 800/900 MHz RF AND PA BOARDS (CONT’D) Ref No Description Part No. Ref No Description Part No. R 254 2.2k ohm ±5% 1/8W smd 569-0105-222 R 527 10 ohm ±5% 1/8W smd 569-0115-100 R 255 56k ohm ±5% 1/8W smd 569-0105-563 R 528 100 ohm ±5% 1/8W smd 569-0115-101 R 256 27k ohm ±5% 1/8W smd 569-0105-273 R 529 680 ohm ±5% 1/8W smd 569-0115-681 R 257 62k ohm ±5% 1/8W smd 569-0105-623 R 530 10 ohm ±5% 1/8W smd 569-0115-100 (800 MHz models) R 531 680 ohm ±5% 1/8W smd 569-0115-681 47k oh

001-9800-001 Q501 Q504 C505 Q514 R516 R517 R544 C562 C563 Q513 B C E F500 R539 R524 C209 C207 C208 C211 C205 C204 C203 CR200 C534 C548 C546 C532 C545 C535 C537 C547 C533 C579 C549 C519 C520 R519 R509 Q500 R540 R541 R548 R542 CR507 C561 J201 J501 R201 C200 C216 R203 R202 C213 C214 C215 Q201 Q200 R211 C233 C232 C235 C236 C237 C234 R210 R213 C240 C239 R212 C230 C242 C241 C244 C245 C243 R217 C247 C252 C246 C254 CR203 R208 L211 C262 R226 C263 MP2 C260 C569 C570 C573 C255 R223 R222 R550 C574 U501 R204

Phone (507) 835-6222. Copyright© 1999 by the E.F. Johnson Company E.F. Johnson Company, which was founded in 1923, designs, manufactures, and markets radio communication products, systems, and services worldwide. E.F. Johnson produces equipment for land mobile radio and mobiletelephone services which include business, industrial, government, public safety, and personal users. Viking Head/EFJohnson logo, LTR-Net™, LTR®, and Call Guard® are trademarks of the E.F. Johnson Company. All other company