Barker & Williamson AS-20 User Manual

BARKER & WILLIAMSON

603 CIDCO ROAD

COCOA, FL 32926

321-639-1510

The Barker & Willamson Model AS-20 is a short dipole for the 20, 15 and 10 meter amateur bands. Each band has a
separate trap (10 and 15 meters) which will give maximum efficiency and still be a short antenna for small lots and limited
space. On 15 meters the 10 meter traps work as loading coils, and on 20 meters both traps work as loading coils, keeping
the antenna short for 20 meter operation. All short dipole antennas will have a bandwidth narrower than a full size half
wave dipole. Therefor, an antenna tuner may be helpful.

The AS-20 is best installed as an inverted Vee. Satisfactory results may be obtained with the center as low as 20 feet,
however 30 feet or more is recommended. If a flat top installation is desired, it is best to have the center supported due
to the weight of the traps/loading coils and coaxial feed line.

INSTALLATION INSTRUCTIONS

WARNING

Outdoor antennas and lead-in conductors from antenna to building shall not cross over electric light or power circuits
and shall be kept well away from all such circuits so as to avoid the possibility of accidental contact. Where proximity
to electric light or power service conductors of less than 250 volts cannot be avoided, the installation shall be such so
as to provide a clearance of at least 2 feet. Where practical, antenna conductors shall be installed so as to not cross
under electric light or power conductors.

MODEL AS-20 ANTENNA
20, 15 and 10 Meter Bands
Power Rating: 1000W PEP, 500W Output
Length: 20 Feet

(1) Please read through all the instructions before starting. It is imperative to follow the instructions step by step, in
the order shown, to achieve satisfactory results with your antenna.

(2) Remember that throughout the assembly procedure, wire lengths are always to be symmetrical on both sides of the
antenna. Your traps may or may not have a color dot on one end of them. You may ignore these color dots. They do not
have to match each side.

(3) Cut the wire segments. The wires must be cut approximately 2 - 3 feet longer than the dimensions shown in figure

1. This is to leave room for the hookups and tuning adjustments. Here are the lengths that you should cut (including the
2 - 3 ft extra). Cut two wires 11', two wires 4', and two wires 3'. Remember, you can always trim the wire shorter after
tuning, but once cut too short . . .

(4) Attach one end of the wire segments in the permanent manner shown in figure 2, working out from the center conductor.
Allow roughly 6 to 8" of wire through the eyebolt before starting your wrap. Attach the 11' segments to both sides of the
center connector. Attach the 3' segments to one side of the TR10 traps. Attach the 4' segments to one side of the TR15
traps.

(5) Now assemble the sections of the antenna together paying attention to figures 1 and 3. The wire segment lengths shown
are your starting point for tuning the antenna. Make sure that you make temporary connections as shown in figure 3. This
will leave each wire segment with one end permanently soldered, and the other end temporarily connected for adjustment.

(6) Raise your antenna, and check the VSWR on 10 meters. If the resonant frequency is low, shorten the 8' 5" segments.
If it is high, lengthen the wires. After the desired frequency is achieved, make permanent attachment for these segments
as shown in figure 2, trimming off excess wire.

(7) Next adjust the 13" segments for 15 meters in the same manner.

(8) Finally, adjust the 21" segments at the insulators for 20 meters.

12/00

Figure 1: Theoretical wire lengths and trap arrangement.

Figure 2: Permanent hookup. After passing
through the eybolt, wrap the wire around itself
5 times before soldering to the terminal.

Figure 4: Typical SWR curves with antenna installed as an inverted
Vee, with center 30 feet high and ends 10 feet above ground.

Figure 3: Temporary hookup
for tuning. Loosely twist and
tape ends in.

WARRANTY STATEMENT

Barker & Williamson guarantees each product to be free from defects in material and workmanship for 90 days from date of
purchase. The warranty applies to the original purchaser only, and we will repair or replace the product at our discretion. Under
no circumstances will Barker & Williamson be liable for any damages or consequential damages arising from use or misuse of
our products. Warranty is voided if product is subject to misuse, neglect, accident, improperly installed or used in violation of
the instructions furnished by us. We reserve the right to make changes in design at any time without obligation to update
previously manufactured models. This warranty is given in lieu of any other warranty, expressed or implied.