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VHF FM Transceiver
VX-261
Service Manual
Introduction
This manual provides the technical information necessary for servicing the VX-261 VHF FM
Transceiver.
Servicing this equipment requires expertise in handing surface-mount chip components. At-
tempts by non-qualified persons to service this equipment may result in permanent damage not
covered by the warranty, and may be illegal in some countries.
Two PCB layout diagrams are provided for each double-sided board in this transceiver. Each side
of the board is referred to by the type of the majority of components installed on that side ("Side
A" or "Side B"). In most cases one side has only chip components (surface-mount devices), and
the other has either a mixture of both chip and leaded components (trimmers, coils, electrolytic
capacitors, ICs, etc.), or leaded components only.
As described in the pages to follow, the advanced microprocessor design of the VX-261 Trans-
ceiver allows a complete alignment of this transceiver to be performed without opening the case
of the radio; all adjustments can be performed from the front panel, using the "Alignment Mode"
menu.
While we believe the information in this manual to be correct, Vertex Standard assumes no li-
ability for damage that may occur as a result of typographical or other errors that may be present.
Your cooperation in pointing out any inconsistencies in the technical information would be ap-
preciated.
This transceiver is assembled using Pb (lead) free solder, based on the RoHS specification.
Only lead-free solder (Alloy Composition: Sn-3.0Ag-0.5Cu) should be used for repairs performed on this apparatus.
The solder stated above utilizes the alloy composition required for compliance with the lead-free specification, and
any solder with the above alloy composition may be used.
Specifications................................................................................................................................................................. 2
Exploded View & Miscellaneous Parts ....................................................................................................................... 3
Parts List ....................................................................................................................................................................... 4
Block Diagram .............................................................................................................................................................. 5
Circuit Description ....................................................................................................................................................... 6
Alignment ...................................................................................................................................................................... 8
Cloning ........................................................................................................................................................................ 15
Main Unit Circuit Diagram ....................................................................................................................................... 16
VX-261 VHF FM Transceiver Service Manual
Vertex Standard LMR, Inc.
Important Note
Contents
©2015 Vertex Standard LMR, Inc.
EC128N90A
1
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Table of Contents
Related Manuals for Vertex Standard VX-261
Summary of Contents for Vertex Standard VX-261
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Page 1: Table Of Contents
(trimmers, coils, electrolytic capacitors, ICs, etc.), or leaded components only. As described in the pages to follow, the advanced microprocessor design of the VX-261 Trans- ceiver allows a complete alignment of this transceiver to be performed without opening the case of the radio;... -
Page 2: Specifications
Maximum Deviation: ±5.0 kHz / ±2.5 kHz Conducted Spurious Emissions: 70 dB below carrier FM Hum & Noise: 40 dB Audio Distortion: <5% @ 1 kHz Specifications subject to change without notice or obligation. VX-261 VHF FM Transceiver Service Manual... -
Page 3: Exploded View & Miscellaneous Parts
PAN HEAD TAPTITE-B ( M2x5 ) ( x13 pcs ) REF. VXSTD P/N DESCRIPTION QTY. U24110001 BIND HEAD TAPTITE-B 2X10 ‚ U44105001 PAN HEAD TAPTITE-B M2X5 Non-designated parts are available only as part of a designated assembly. VX-261 VHF FM Transceiver Service Manual... -
Page 4: Parts List
MFT50.85P 50.85MHZ H1102361 SHIELD CASE COVER (FET) RA125020A RING NUT (x2 pcs) RA157250A PAN HEAD TAPTITE-B (x13 pcs) (M2X5) U44105001 When replace a chip fuse, use the part of the same type and value. VX-261 VHF FM Transceiver Service Manual... -
Page 5: Block Diagram
Block Diagram VX-261 VHF FM Transceiver Service Manual... -
Page 6: Circuit Description
The stronger signal makes the RSSI voltage to be higher voltage. The process of the AF signal control is same as Noise Squelch. The shipping data is ad- justed 3 dBµ (EMF) higher than squelch tight sensitivity. VX-261 VHF FM Transceiver Service Manual... - Page 7 The CPU Q1028 (R5F100LHDFB) is always watch- Power “High” and “Low”) controlled by the Electric Vol- ing over the UL condition, and when it becomes “Low” ume IC Q1018 (AK2330). unlocked condition, the CPU prohibits transmitting and receiving. VX-261 VHF FM Transceiver Service Manual...
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Page 8: Alignment
Because of the BTL (Bridged Trans Less) Amplifier cir- reserves the right to change circuits and alignment pro- cuit used in the VX-261, do not connect earth side of the cedures in the interest of improved performance, without speaker leads to chassis “ground”. -
Page 9: Test Setup
MIC/SP Coupler Transceiver FRB-6 Inline D-Sub 15-pin MIC IN Generator Wattmeter Connector Battery Terminal CLONE Port CT-104A, CT-106, or CT-171 Power Supply Computer FIF-12 Deviation ( CE150 ) 7.5 VDC Meter Frequency Oscilloscope Counter VX-261 VHF FM Transceiver Service Manual... - Page 10 (ADJ Type), as needed. Basic: “Low Edge / Band Center/ High Edge” and select the channel for alignment (Default). Single: Alignment value changes only on the selected channel. All Freq: Alignment value changes on all channels. VX-261 VHF FM Transceiver Service Manual...
- Page 11 Tight RSSI Level (Wide/Narrow) Other alignment items has not extra step; only one step proce- dure. 6. Click the “OK” button, then the data will be saved and the alignment is finished. ê ê VX-261 VHF FM Transceiver Service Manual...
- Page 12 (ADJ Type), as needed. Basic: “Low Edge / Band Center/ High Edge” and select the channel for alignment (Default). Single: Alignment value changes only on the selected channel. All Freq: Alignment value changes on all channels. VX-261 VHF FM Transceiver Service Manual...
- Page 13 (ADJ Type), as needed. Basic: “Low Edge / Band Center/ High Edge” and select the channel for alignment (Default). Single: Alignment value changes only on the selected channel. All Freq: Alignment value changes on all channels. VX-261 VHF FM Transceiver Service Manual...
- Page 14 Ÿ Entering the value (“0” - “255”) in the “Data” box from the computer’s keyboard 4. After getting the desired deviation, click the “PTT” button to stop transmitting. 5. Click the “OK” button to finish the Sequential Tone Deviation alignment and save the data. VX-261 VHF FM Transceiver Service Manual...
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Page 15: Cloning
The VX-261 transceiver includes a convenient “Cloning” feature, which allows the programming data from one transceiver to be transferred to another VX-261. Here is the procedure for Cloning one transceiver’s data to another. 6. Press the PTT switch on the Source transceiver. The 1. -
Page 16: Main Unit Circuit Diagram
Main Unit Circuit Diagram VX-261 VHF FM Transceiver Service Manual... - Page 17 No portion of this manual may be reproduced without the per- mission of Vertex Standard LMR, Inc. Vertex Standard is a trademark of Vertex Standard LMR, Inc. All other trademarks are the property of their respective owners. ©2015 Vertex Standard LMR, Inc.