Introduction: 1. The frequency meter capable of measuring the parameters of the frequency of the continuous carrier signal walkie-talkies , with signal strength indicator. it is the tool of choice for maintenance personnel,test frequency and signal strength of wireless enthusiasts. 2. This portable frequency counter is designed for counting continuous wave signal comes from Two-way Radio. 3. There are easy ranges for you to choose. The ranges cover most of the frequency of the two way radios you want to measure. 4. Its four-button control is easy to use and its small size allows you to carry it anywhere you like. 5. Work by TCXO(Temperature Compensate X'tal (crystal) Oscillator) ,In the range of -45~ 65 degree can reach ± 2 ~ ± 4ppm accuracy This include very interesting frequency areas such as 2m HAM radio, all VHF and UHF DMR Radio signal e frequency counter. Easy Battery level Q&A of SF-401 plus Frequency Counter Problem: Frequency counter cannot check VHF frequency Solutions: 1) Swtich the ATT button into left hand side 2) Then change the antenna into VHF or Dual band, as customer are using UHF antenna, but checking VHF band 3) If you really using the UHF antenna to check it, please try to slant your radio to the frequency counter, like the following picture Please Note: (27MHz to 100MHz It can not be guaranteed and the corresponding normal emission appliance) Note that different frequencies have different sensitivities, if the signal is too weak, to replace the antenna. Package Contents 1x SF401 Plus Frequency Counter 1 x UHF Antenna 1x User Manual 1x USB charger cable 1x USB AC adapter 100-240V Feature & Specification: Frequency range: 27Mhz-3000Mhz CTCSS/DCS Decoder LCD Dim level setting Frequency digital 0.000 or 0.0000 Work by TCXO(Temperature Compensate X'tal (crystal) Oscillator) 2~2.5ppm Frequency Rresponse time: 0.2-0.5sec.( CTCSS/CDCSS >0.5-1sec) Color Display 240x320 Build-in Li-ion battery Net Weight: 113g 4 buttons control Auto power off 1-9minutes Charging battery LED indicator