Bavis BavCom One on One Manual

201 Grandin Road
Maineville, Ohio 45039
[phone]
BavComTM One on One Audio System
Installation and Service Manual
Copyright 2020 E. F. Bavis & Associates, Inc. Revised: 10/29/2020
All Right Reserved PN: 00607011

BavCom One on One Audio
Table of Contents
Features ................................................................................................................................1
Installation ...........................................................................................................................2
Connecting Cable(s) Diagram .............................................................................................4
Adjustments .........................................................................................................................5
Troubleshooting ...................................................................................................................6
Installation & Service Tool List...........................................................................................7

1
BavCom™ One on One Audio
The BavCom™ One on One audio system lets one inside position talk to one remote position.
Features
 Full duplex operation
 Electret condenser microphone
 Proprietary closed back speaker for maximum efficiency and minimum feedback.
 Case is of heavy 16ga steel & 0.080” aluminum construction with a durable powder
coated finish and discrete BavCom audio board/components.
 Inside microphone and speaker are built into the console unit.
 Built-in call tone is included in the console.
 Easy electrical connections.
One round plug-in jack for the AC power which comes from a UL
Listed 24vac plug-in transformer. Convenient terminal barrier or
Molex type connection for the remote speaker, microphone and
call button.
 Two inside controls:
Rocker switch for Standby and ON.
Incoming volume control knob.
 Standard service adjustments.
Incoming and outgoing gain controls. See section labeled
ADJUSTMENT for more information.

2
Installation
Console:
The console is designed to sit on the counter top. The speaker faces backward.
The power comes from a UL Listed transformer supplied with the kit, part number 01521011.
Plug the round end of the transformer provided into the round jack at the rear of the console.
Plug the transformer into a 120vac outlet.
Customer End:
Make the customer audio component connections. These connections are via a 9 position pre-
wired connector or a terminal barrier for easy plug-in, quick-slide, or screw type connections.
See Fig. 1 for the order of connections.
External Audio Components:
We supply many different types of external audio components. These must be selected to suit
the needs of the applications. The rugged, weatherized components that we supply are designed
specifically for outdoor audio communication. Off the shelf Hi-Fidelity components are not
weatherproof, nor were they designed for the rigors of the drive-thru environment, hence, they
do not last long when used.
We have found that for proper sound quality, to reduce squealing and have sufficient gain levels,
the speakers must have back-boxes. We supply back-boxes or closed back speakers in all of the
audio systems we manufacture. In addition, we offer back-boxes for use in retrofit applications
that may benefit from them. These parts can be ordered separately from the list below. If you
need help in choosing the proper components, please contact us.
For a complete customer audio panel for use with the Transaction Drawer™, order P/N
00539992. This is an engineered solution which includes matching black powder coated trim,
mounting plates, speaker, isolation mounted microphone with acoustical back-box, and a call
button all with 10' leads.
Separate microphones and pre-amps are available in various versions:
25" boom type with 3/8" threaded stem and nut, typically used for inside positions,
microphone part number 02908033, pre-amp part number 02908231.
36" boom type with 3/8" threaded stem and nut, part number 02908032.
Boom type with flat mounting plate is available under part number 02908191.
Diamond style that includes a molded housing that is designed for surface mounting,
microphone part number 02910992, pre-amp part number 02908241. This type is secured
from the rear with screws.
Black flange microphone kit, part number 22151991.

3
Separate speakers are also available in a variety.
50mm with flush mounting plate which features integral grill, part number 09033121.
50mm with adapter plate to replace 4” speaker assembly, part number 02909992
Separate call buttons are available in various types.
Call Button Replacement Kit, part number 00353991
Polyester identifying labels, part number 00207012
Composite cable, part number 02910011, is available by the foot. This has 3 pairs in one cable
and was especially designed and made for our audio.

4

5
Adjustment
It is necessary to disassemble the console to adjust the gain controls. Disassembly of the console
is done by removing the four screws on the bottom of the console that secure the top to the
bottom. Carefully separate the two halves. For details on the location of the adjustments, see
Figure 1. The adjustments are labeled on the board.
INCOMING OUTGOING
R10 C24
Q1
D17 L1
U2
D18 R37
R13
R14
D14
D13
D1
C26
C25
D10
D9
C13
C14
D16
C29
D15
R20
D2
C33
D11
D12
D20
D19
C34
Q2
U4
U1
C32
R27
Q3
R26
C31
C30
BZR1
F1
J1 C23 VR1
U3
C7
R6 R8
C10 C9
R23 R7R9
C11
R5
R31 R29
C6
R30 R21 R33 R32
C2
R15
R18
C21
R16
C18 C20
R24 R17
R19
R28
R25
D7 D5
D8 D6
C12
R35 R34
C17
R11 R22 R36 R12
C1
P/N 22118011 REV 11/06
FABACRAFT DUPLEX AUDIO P/N 22118011 REV 11/06
(PRINTED ON UNDERSIDE OF BOARD)
Fig. 1
With the employee speaking in the inside microphone and a car present, the outgoing gain
control should then be adjusted for satisfactory volume. The incoming gain control should then
be adjusted clockwise until feedback occurs, then counterclockwise until feedback stops. This
should complete the adjustment. If the incoming level is not sufficiently high enough, the
outgoing level will have to be reduced to be able to get additional incoming volume level. The
gain levels are a balance; adjustment of each has an effect on the other. If the incoming level is
too high, adjust it to a lower level. Reassemble the console. Note: The incoming volume knob
should be all the way clockwise for this procedure.

6
Troubleshooting
Audio doesn't work
Outlet on?
Transformer plugged in?
Check for 24vac at connector end. No 24vac? Replace transformer.
Still doesn't work? Replace console.
No incoming (Assumes outgoing audio)
Adjust gain.
Doesn't work? Replace remote microphone.
Doesn't work? Replace console speaker.
Doesn't work? Replace audio board.
Doesn't work? Consult factory.
No outgoing (Assumes incoming audio)
Adjust gain.
Doesn't work? Replace console microphone.
Doesn't work? Replace remote speaker.
Doesn't work? Replace audio board.
Doesn't work? Consult factory.
No call tone (Assumes audio works)
Check call button for continuity when depressed with leads disconnected.
No continuity? Replace button.
Continuity? Replace audio board.
Doesn't work? Consult factory.

7
Installation and service tool list for audio
1/8” And 3/8” Flathead Screwdrivers
#0 And #2 Phillips Screwdrivers
1/16” And 3/32” Allen Wrenches
1/2" Open-End Wrench
1/4", 5/16”, 11/32”, 3/8”, And 1/2" Nut Drivers
Wire Cutters
Wire Strippers
Wire Crimpers
Volt Meter
Electric Drill
Drill Bits
Level
7/8” Unibit
Fish Tape
Loctite

Revisions:
ECN Date
3835 03/28/2003
4061 06/11/2003
8249 02/27/2007
13533 02/27/2012
21533 10/28/2020