GOOZEEZOO 2pcs Donut VHF UHF FM 400M-470MHz 80M-150MHz Mini Loop Antenna | 80-150MHz VHF & 400-470MHz UHF Dual-Band Coverage, 50Ω, SMA Donut Antenna($26.99Value)

Description

Superior Performance: This UV UHF + VHF FM Mini Loop Antenna covers wide frequency bands: UHF 400MHz-490MHz, VHF 80MHz-200MHz with 50Ω impedance. Tunable design optimizes gain for different frequencies, delivering stable and outstanding signal performance. Ideal for amateur radio, emergency communication, field activities and mobile radio use Frequency Range & Specs: UHF: 400MHz ~ 490MHz VHF: 80MHz ~ 200MHz Impedance: 50 Ohms Function: Transmit & Receive Interface: Standard SMA Connector Tunable Design for Optimal Signal: Equipped with a top tuning knob (butterfly variable capacitor). Rotate the knob to adjust resonant frequency and maximize signal gain. The large loop features 180° mechanical limit to protect internal components; the small loop adopts limitless fine-tuning structure for precise frequency adjustment. Easy to calibrate for different working bands Compact and Portable: Designed to be compact and portable, making it easy to take with you wherever you go. Whether you're heading out on a camping trip, participating in a field day event, or just need a reliable antenna for your mobile radio, the Donut antenna is the perfect choice. Its compact size and lightweight construction make it easy to store and transport Easy to Install & Operate: Plug-and-play design with standard SMA interface. No extra tools required, ready to use within minutes. Simple tuning operation helps you quickly get the best signal effect Function of the black knob on top: This knob controls a butterfly variable capacitor. Rotating it changes the capacitance to adjust the resonant frequency of the loop antenna. It helps the antenna work well on different VHF/UHF bands and achieve the best receiving gain. Large loop (only rotates half a turn): The 180° limit is a built-in mechanical stop of the butterfly capacitor. Forcing it to turn further will cause short circuit and permanent damage to the capacitor. Do not rotate it violently. Turn the knob slowly within the half-turn range while checking the signal meter of your receiver, and set it at the position with the strongest signal for your target frequency. If no optimal signal is found, you may open the top cover and slightly adjust the stop plate to extend the working range. Do not exceed 180° in total rotation Small loop (rotates continuously): It is fitted with a fine-tuning capacitor without mechanical stops, so it can rotate freely. Turn it clockwise or counterclockwise slowly to fine-tune and locate the strongest signal. If the knob slips, tighten the small set screw at its base to increase friction. Electrical connection with the main loop: The variable capacitor driven by the knob is soldered in series across the opening of the full-circle loop. The loop acts as an inductor, and together with the capacitor, they form an LC resonant circuit for frequency tuning. All wiring is hidden inside the plastic housing at the top center. Specification:
Color: as picture shown
UHF antenna: 400MHz ~ 490MHz
VHF antenna: 0MHz ~ 200MHz
Diameter:
UHF antenna: 5cm
VHF antenna: 10cm
Package included
1 x Donut UHF Antenna
1 x Donut VHF Antenna