Quick Start Manual
Installation Instructions
AUTOMATIC GATE AND DOOR
RADIO CONTROLS
12-24V RECEIVER
WARNING:
•  Disconnect power before any installation or repair.
Your Multi-Code Radio Controls are designed specifi cally 
for the remote control of industrial door or gate openers and 
to give years of dependable service without adjustment.
SELECTING AN OPERATING FREQUENCY
Place the shunt on the 2 pins of P1 that correspond with 
the desired frequency of operation. P1 is labeled “Multi” for 
300 MHz operation and “Stanley” for operation at 310 MHz. 
NOTE: If the shunt is not used, and the pins of P1 are left 
open, the default frequency is 310 MHz.
SELECTING A CODE
The code is determined by the positions of the 10 small 
switches numbered 1 through 10 located on the receiver 
board. Set these code switches to match the transmitter’s 
code switches. To gain access to the switches, remove the 
rear section of the case by squeezing the side. 
Any combination of ON (CLOSED) or OFF (OPEN) 
positions can be selected by using a pointed object such as 
a small screwdriver or paper clip. We strongly urge that you 
avoid the following code schemes: ALL ON, ALL OFF, 2, 4, 
6, 8, 10, ON or 1, 3, 5, 7, 9, ON. These codes are frequently 
used by other manufacturers, and create the possibility of 
false operation, and may be less secure than other code 
schemes.
1
2
3
5
6
78
910
OPEN
CODE SWITCH
The MC302850, two-channel receiver has only 9 code 
switches. Set them to match switches 1-9 on the transmitter. 
The channel of operation is determined by the position of 
switch 10 on the transmitter (OFF- CH1, ON-CH2).
Be certain to check that the code is functional before 
completing the installation.
INSTALLATION
The receiver comes equipped with an F-connector 
receptacle and an antenna with an F-connector plug. The 
antenna can be plugged directly into the receptacle, or it 
can be moved away from a metal structure, or to an outside 
location for better receiver performance by using the coaxial 
cable which is included.
Begin your installation of the receiver by correctly wiring 
the receiver to the devices you will be using. WE URGE 
YOU TO BECOME FAMILIAR WITH THE INSTRUCTIONS 
THAT THE MANUFACTURER OF YOUR EQUIPMENT 
HAS PROVIDED. SINCE, IN MANY CASES, THESE 
INSTRUCTIONS DETERMINE THE WAY IN WHICH THE 
RECEIVER SHOULD BE INSTALLED.
The receiver should be mounted near the opener power 
head and can be installed in any position by using screws 
and the two slots in the cover fl anges. Select a location and 
position that permits access to the terminals and space for 
the antenna as clear of metal structures as possible and 
preferably in a vertical position.
Wire the red and black wires to the power source. 
The input voltage is: 12.0 - 30 AC
     10.6 - 30 VDC (Red + Black -)
Connect the remaining gray wires as specifi ed by the 
manufacturer of your operator. If such instructions do not 
exist, wire the two gray wires in parallel with the pushbutton 
terminals. If the operator has a three wire terminal, the 
proper terminals will usually be marked “1” and “2” or “24V” 
and “RELAY” .
At this point you should mount your receiver to its 
permanent location, if you have not already done so.
The receivers come with the output wires connected 
between the relay common and normally open contacts. 
Normally closed contacts can be selected by moving the 
channel’s output wire from the N.O. to the N.C. post on the 
circuit board.
The output wires are:
  Gray: Channel one
  Yellow: Channel two
ANTENNA INSTALLATION
After you have mounted your receiver, test it with the 
enclosed antenna for range, noting the coverage that you 
get from all desired operating locations. If greater range 
or coverage pattern is necessary, you may need the 1066 
Coaxial Wiring Kit, which is available from your dealer. It is 
not advisable to add lengths of coaxial cable greater than 
20 feet, as this may affect range or tuning.
ADDITIONAL INSTALLATION INFORMATION
Linear Corporation has taken every possible precaution 
to make the receiver as reliable as possible. We think the 
following notes should be observed:
1. Be sure the unit is sealed from moisture, and, if at all 
possible, keep it away from direct moisture.
2. In those installations where vibration may be a factor, be 
sure to use a fastening compound, such as LOCTITE (TM) 
on the mounting screws to insure reliable mounting.
OPERATIONAL CHECK
To check operation, move back a reasonable distance 
(about 50 feet) and press the transmitter button. Operation 
should be reliable at this distance but environment and 
location of both the transmitter and receiver will affect the 
range. If the transmitter is stowed well out of sight, it may be 
necessary to remove it from its mounting and hold near the 
windshield. Try different locations and positions. If operation 
is still unsatisfactory, check the following:
1. The antenna must be connected to the receiver for 
normal use.
2. If the opener fails to operate, check to see that 115 VAC 
power is present. Check circuit breaker. Check for a system 
power failure.
3. If the opener operates by pressing the wall button, but not 
when the transmitter button is pressed, the radio controls 
are probably at fault. Check to make sure both transmitter 
and receiver code switches are set to the exact same code 
since a difference of just one switch will prevent operation. 
Check transmitter battery, location of the transmitter and 
receiver installation.
4. Try mounting the antenna in a more favorable remote 
location by utilizing the coaxial kit.
If, after performing the above operational check, it is 
necessary to return the radio controls, return both the 
transmitter and receiver to your dealer for repair or 
replacement or they may be returned, postage prepaid, 
directly to Linear Corporation.
WARRANTY
All MULTI-CODE garage door related products carry 
an eighteen (18) month warranty against defects in 
workmanship or material. This warranty begins at the date 
of manufacture, for eighteen months. Linear Corporation 
warrantees our product only to our authorized dealers and 
distributors, and not to the end customer. If you have any 
questions about our warranty, please ask your dealer to 
determine the nature and scope of his warranty. Linear 
Corporation does not assume, and is not responsible for, 
any real or consequential damages from claims against 
the performance of our product, nor is it liable for any costs 
related to loss of life, property, or revenue. Further, Linear 
Corporation is in no way responsible for installation of 
our product, and will assume no costs to re-installation or 
removal. Linear Corporation’s Warranty is in lieu of all other 
warranties, expressed, or implied.
CAUTION: Any changes or modifi cation in intentional or 
unintentional radiators which are not expressly approved by 
LINEAR CORPORATION could void the user’s authority to 
operate this equipment. 
LINEAR CORPORATION
2055 Corte del Nogal 
Carlsbad, CA 92009
(760) 438-7000
Copyright © 2003 Linear Corporation  221426 A
RECEIVER
CONTROL
BOX
BLACK
GRAY
RED
GRAY
1
2
3
YELLOW
YELLOW
CH2
®
SHUNT SET FOR
"MULTI" OPERATION
SHUNT SET FOR
"STANLEY" OPERATION
SQUEEZE BOTH SIDES AT TABS
AND TILT UPWARD
PRINTER’S INSTRUCTIONS:
INSTR,INSTL,MULTICODE 12-24V RX - LINEAR P/N: 221426 A - INK: BLACK - MATERIAL: 20 LB. MEAD BOND - SIZE: 9.000” X 13.000” - SCALE: 1-1

