Bolt Panel Antenna v4.0: Best Practices

GENERAL

• When powering on the Bolt 4K transmitter and the Bolt 4K receiver attached to the Bolt Panel Antenna v4.0, keep both units within the maximum range (1.5 km or 5000 ft). If the transmitter and/or receiver are moved beyond the maximum range, and the signal is dropped, you will need to move Bolt 4K within 95% of the operating range in order for the units to reconnect.
• Operation of other wireless transmitters and receivers may interfere with Bolt 4K’s performance and/or limit the maximum range.

MOUNTING

The Bolt Panel Antenna has three 3/8in threaded holes:

• One on the bottom for mounting the included light stand adapter or any 3/8in mounting accessory.
• One on each side to mount to a yoke mount bracket assembly

                  3/8 Mounting Accessory                                   Yoke Mount Assembly

• Mount the Bolt Panel Antenna vertically, keeping it clear of any obstructions.
• Orient the transmitter and receiver so they are parallel to each other.
• For best results, orient the receiver so the front (with the Teradek logo) has a clear line−of−sight to the transmitter.

ANTENNA RECEIVE PATTERN

The Bolt Panel Antenna has a built-in directional antenna with a receive pattern that varies based on its distance to the transmitter. The horizontal receive angle measures 55° at 5,000 ft (1.5 km), 104° at 4,000 ft (1.5 km), and is effectively omnidirectional at up to 500 ft (150 m). The vertical receive angle measures 20° at any distance.

POSITIONING

When positioning the Bolt Panel Antenna, you must also consider the radio frequency line of sight. Most people think that having a clear RF line of sight between transmitter and receiver just means maintaining visibility between one and the other. Besides the line itself, obstructions in areas near the line joining the transmitter and receiver, known as Fresnel zones, can cause significant RF interference. Fresnel zones are actually what define the RF line of sight.

FRESNEL ZONE

Fresnel zones are long ellipsoid areas surrounding the visual line of sight between two RF points (receiver and transmitter). When radio waves are transmitted, they spread out within these zones. The size of the ellipse is determined by the frequency of operation (e.g. 2.4 GHz, 5GHz) and the distance between the two points. When there is considerable distance between the transmitter and receiver, a portion of the Fresnel zone might be obstructed by buildings, mountains, or other obstacles. The greater the distance between the two RF points, the wider the radius of the Fresnel zone, and as a result the greater the possibility of the RF signals from either point encountering some interference.

Some obstruction of the Fresnel zones can often be tolerated. Typically, 20% Fresnel Zone obstruction introduces little signal loss to the link. Signal loss will become significant once obstruction is beyond 40%.

In order to maintain signal strength, you need to adjust the height of the receiver and/or the height of the transmitter accordingly so that there is no more than 20% obstruction. Below is a table showing distances between antennas and the required radius.*

*Does not take into consideration obstacles or environmental interference

FORMULA FOR FRESNEL ZONE RADIUS

The distance between the two antennas (kilometers/miles) is represented by d, and f represents the frequency (in GHz) at which you are transmitting.

The radius of the Fresnel Zone at its widest point can be calculated by the following formula: 

In meters = 17.32 * square root of (d/4f)

 In Feet = 72.05 * square root of (d/4f)