Barker & Williamson AP-10A User Manual

BARKER & WILLIAMSON

www.bwantennas.com

603 CIDCO ROAD

COCOA, FL 32926

321-639-1510

The AP-10A is a base loaded style antenna for 10 through 40 meters continuous frequency
coverage (all frequencies from 7 through 30 Mhz). Operation on 2 and 6 meters is also provided
without the use of loading coils. The bracket design allows simple installations for apartments,
townhouses, trailers, boats, hotels, etc. It has proven its ability to provide a quick and dependable
antenna system when regular antennas cannot be used. The AP-10A has also found application
in emergency communication work when conventional antennas have been put out of service.
When adjusted properly to your operating frequency, VSWR is 1.1:1.

As in any vertical type antenna, a ground radial system or counterpoise is essential for maximum
results. The AP-10A utilizes a counterpoise to make the antenna function properly. By adjusting
the counterpoise length, you will be able to compensate for varying conditions due to surrounding
objects, grounds, etc.

SETUP

Referring to figure 1, mount the coil assy to the window bracket with the large wing nut and washer, placing the coax ground lug
and counterpoise lug (no counterpoise for 2 or 6 meters) underneath the wing nut. Attach the center conductor of the coax cable and
fly lead to the lower end of the coil, using the small wing nut and washer as illustrated. A plastic clamp and hardware is included to use
as a strain relief for the cable. Place the antenna whip on the other end of the coil assy and use the two small set screws to secure it. Extend
the whip to full length and clamp the bracket to your support. If the support is metal, insulate the bracket using material such as cardboard
or thin wood.

OPERATION

MODEL AP-10A ANTENNA
40 - 10 Meters Continuous Coverage
6 and 2 Meter Bands
Power Rating: 300W PEP

To properly utilize the antenna, you must perform two steps to tune it for your frequency of operation. First, the fly lead must be set on
the coil. Then, the counterpoise length is adjusted and fine tuned for good VSWR. The table will give you settings for common bands.

To set the fly lead on the coil, check the table for the number of windings down from the top of the coil to clip to. Figure 2 shows how to
count the windings from the top (the end the whip attaches to), and where to locate common bands. When using the clip on the fly lead,
make sure that the screw is loose before pushing on or pulling off the coil wire, then tighten the screw moderately. The clip is best attached
next to a plastic rib on the coil, where the wire is held up the highest from the PVC support pipe underneath.

When adjusting the counterpoise length, roll up the unused portion into a coil. A giant size paper cup works great for this, or simply use
your hand. Start out at the suggested length in the table, and then fine tune with a VSWR meter or power meter. The counterpoise may
be laid on the floor. Best results will be obtained with the counterpoise parallel to the antenna. For rooms above the ground floor, slight
improvement in operation can sometimes be noted by hanging the counterpoise outside, down the wall. For operation on a boat or mobile
home where the deck or floor is metal, the counterpoise may have to be stretched two or three feet above that surface. When you achieve
a good SWR, mark the counterpoise and coil for a favorite band with a magic marker. If you cannot adjust the SWR low enough with the
counterpoise, but have seen a definite dip, you need to readjust the flylead. Note that the higher the frequency you are working with, the
more sensitive the adjustments become.

On 2 and 6 meters, the coil is bypassed with the fly lead , and the counterpoise is not used. Antenna whip length may be adjusted as necessary.

COIL / COUNTERPOISE TABLE

Frequency Fly Lead Coil Adjustment Counterpoise

40 meters Use all of coil, detach the fly lead 35 - 40 Ft
30 meters Attach fly lead 25.5 turns down from top (point E in Fig 2) 17 Ft
20 meters Attach fly lead 14.5 turns down from top (point D in Fig 2) 12.5 Ft
17 meters Attach fly lead 10 turns down from top 9 Ft
15 meters Attach fly lead 6.75 turns down from top (point C in Fig 2) 7 Ft
12 meters Attach fly lead 5 turns down from top 5.5 Ft
10 meters Attach fly lead 4 turns down from top (point B in Fig 2) 4.5 Ft
6 meters Bypass all of coil with fly lead (point A in Fig 2) No counterpoise. Ground bracket.
2 meters Bypass all of coil with fly lead (point A in Fig 2) No counterpoise. Don't ground bracket.

Coil and counterpoise settings may vary some in your installation due to ground conditions. Note that any frequency between approx 7
and 30 Mhz may be tuned with the coil. First, set the coil clip by interpolating from the table, then tune the counterpoise with a VSWR meter.

Attach antenna with
two set screws.

Antenna Whip

Connection

A

1

B

5

C

10

Connect Fly-lead and coax
center conductor here. Use 6-32
lockwasher and wing nut.

Connect counterpoise and coax
braid here. Use 1/4-20 lockwasher
and wing nut. This also holds coil
assy to the bracket.

Secure coax
here with cable
clamp, and 6­32 hardware.

NOT TO SCALE

Fly Lead

44

15

20

25

30

35

40

D

E

1/4-20 Stud for

Support Bracket

Figure 1 Figure 2

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.

4/02