Service manual

Installation

DCB, DCFCB and DCFCTB Models

3. Insert the elements into their respective locations through the boom, starting with

R1 (the reflective element) in the hole closest to the mounting holes. Then insert

Dr, D1 etc. in that order.

Note A: Shortest element is furthest away from the mount and increases in size as

it gets closer to the mount.

Note B: Be very careful to line up the holes and not cross thread when securing

the elements in the next step. The bolts must tighten all the way down

upon the lock washers.

4. Secure the elements with the stainless steel 10-32 hex bolts and #10 lockwashers

provided.

5. Locate the connector/brass tube assembly in the gamma match parts bag and

insert the assembly first through the connector bracket, then thread the connector

into the bracket. Be sure to tighten the connector fully. A drop of Locktite or

other thread lock may be used in the threads to eliminate the possibility of the

connector loosening.

6. Slide the gamma link onto the driven element and assemble the gamma match as

shown in figure 1 or 2 (under the antenna instructions provided by the antenna

manufacturer). Set dimensions “A” and “B” to those shown in table 1. Setting the

match to the dimensions shown for your antenna is a good starting point, which

allows you to quickly line tune later. Complete the assembly by attaching the end

cap onto the end of the gamma tube. The antenna is now ready for final tuning.

Final VSWR tuning

1. Before final installation of the antenna, temporarily set it up in a clear area at

least six feet above the ground.

Note A: Do not touch the antenna while the radio is transmitting.

Note B: Ensure antenna is not touching any conductive material and is pointed

away from all objects and people. Pointing antenna at objects in close

proximity may act as a reflector and create inaccurate readings.

2. Apply RF power to the antenna at the transmit frequency to be used at that

antenna, and check for the low VSWR while performing each of the following

steps.

A. Loosen the setscrew with the Allen key provided and make a slight

adjustment to the aluminum gamma tube for the lowest VSWR (Reflected

power).

B. Adjust the gamma link along the driven element for the lowest VSWR.

C. Repeat the above steps until the lowest VSWR is achieved. Reflected power

must be less than 10% of the forward power.