SF-401PLUS Frequency Counter

Introduction

• Measures frequency parameters of continuous carrier signals from walkie-talkies with signal strength indication.
• Designed for test and maintenance personnel and wireless enthusiasts.
• Portable; covers most two-way radio frequency ranges.
• Features 4-button control and compact size.
• Operates with TCXO for stable frequency compensation (±2 to ±4 ppm accuracy from -45℃ to 65℃).
• Supports 2m HAM radio, VHF, UHF, DMR radio signals.
• Includes digital mode for DMR radios only.

Features & Specifications

• Frequency range: 27 MHz - 3000 MHz (*27-100 MHz not guaranteed)
• CTCSS/DCS decoder for 136-174 MHz and 400-520 MHz bands only
• Frequency digital resolution: 0.000 or 0.0000 (±0.001)
• Frequency response time: 0.2-0.5 s (CTCSS/DCS 0.5-1 s)
• TFT Color Display 240x320 pixels with adjustable brightness
• Built-in rechargeable Li-ion battery, approx. 113 g weight
• Auto power off (1-9 minutes) with LED battery charging indicator

Usage Highlights

• Power On/Off: Hold [black key] for 2 sec to power on; hold for 4 sec to shutdown.
• Charging: Connect micro USB; red LED = charging, green LED = full.
• Signal Testing: Keep transmitter near antenna with green signal bar for valid measurement; red means too close, low bar means weak signal.
• Digital DMR Mode: Press [F3 Digital] on measuring screen (shows frequency with 3 decimals).
• Menu Settings: Enter with [F1], navigate with [F3]/[F4], edit with [F2]. Save and exit with [F4].
• RF Defect Level: Lower levels increase sensitivity.
• CTCSS/DCS Decoding: Works only in ANALOG mode with radio frequency 136-174 MHz or 400-520 MHz.

CTCSS Frequencies Table (Hz)

CDCSS Codes Table (Analog Mode, N Code only)

Refer to detailed frequency and code tables in original content for full list.

Package Contents

• 1x SF401 PLUS Frequency Counter
• 1x UHF Antenna
• 1x English User Manual
• 1x USB Charger Cable
• 1x USB AC Adapter (100-240V)