One hertz is one cycle per second, meaning repeating cycle as an event. For example, hertz is applied physics measuring the number of times for a second wave (either acoustic or electromagnetic) is repeated or can be applied, among other uses, to ocean waves that reach the Beach vibrations per second or a solid. The quantity that measures the frequency hertz is called,in this regard, the inverse of the period. One hertz is an oscillation frequency of suffering a particle over a period of one second.

The UHF connector, also called coaxial connector Amphenol is a RF connection design, created at a time when "UHF" referred to the frequencies above 30 MHz. Originally designed to be used as a video connector radar applications, the connector was later used for RF applications. This connector was developed on the basis of a shielded banana plug.

The UHF band that could normally associated with television channels, is a Spanish band in the electromagnetic spectrum, ranging from 300 MHz to 3 GHz. The UHF band can be affected by variables such as humidity, solar wind, or the time of day that will attempt to connect the device. Although as positive could define the UHF frequency band is high, hence its advantages over short distances.Ultra High Frequency (UHF) Cycles per second: 300 MHz to 3 GHz Wavelength: 100 mm 1 m

VDC would be the abbreviation for Volt Direct Current which translated would volts direct current. The idea of ??this type is unidirectional current to the load. Direct current is normally produced by batteries, thermocouples, solar cells and a dynamo electric machine type. The direct current can flow in conductors such as wires, but may also flow through semiconductors, insulators ... In the image: 1 - current per pulse 2 - Direct Current (DC) 3 - Alternating Current (AC) 4 - Variable Current

Within the wide range of batteries on the market we can differentiate two large groups, disposable batteries and rechargeable batteries.
Disposable batteries are those that only allow a single use and when they are exhausted they can not be recharged. These batteries can store their energy for years.

Rechargeable batteries are those that can be recharged once exhausted. This type is losing charge when they are storedaccording to voltage. The most common we can find them of 1.2V and 3.7V

As a last point you have to take into account that lithium batteries, Lipo, Life etc. Due to its composition, specific loaders should be used.