How to set up and use a affordable Nano VNA meter to check your antennas SWR range and look for faults. Build your own antennas and check and adjust their peak SWR easy with this cheap meter. Great for CB radio. Buy here. https://ban.ggood.vip/14bQC

NanoVNAPCB 10KHz1.5GHz MF HF VHF UHF Digital Vector Network Antenna Analyzer Support 32G SD Card
Specification:

PCB: 54mm x 85.5mm x 11mm without the size of connectors, switches
Measurement Frequency: 10KHz 1.5GHz
RF Output: 13dbm maximum 9dbm
Frequency Accuracy: 0.5ppm
Measurement Range: 70dB 50kHz300MHz, 50dB 300M600MHz, 40dB (600M900MHz) enable extended firmware)
Port SWR: 1.1
Display: 2.8 inch TFT (320x240)
USB Interface: USB TypeC; Communications Mode: CDC (Serial)
Power Supply: USB 5V 120mA, builtin 650mAh electricity, maximum charging current 0.8A
Number of Calibration Points: 101 (Fixed)
Number of Scanning Points: 101 (Fixed)
Display Tracking: 4, Marking: 4, Save Setting: 5
Measuring S parameters, voltage standing wave ratio, phase, delay, Smith chart and the like

Package included:

1 x NanoVNA Host (2.8inch touch screen and 650mAh battery is included)
2 x 20cm SMA Male to Male RG174 RF Cable
1 x USB TypeC Data Cable
1 x Typec to Typec Line
1 x Stylus Pen
1 x Touch Paddle
2 x SMA Female to Female Connector
1 x SMA Simple Calibration Kit SHORT
1 x SMA Simple Calibration kit OPEN
1 x SMA Simple Calibration kit LOAD
2 x SMA Female to Female Connector