Transmitter Solutions EMP300MCD21V-C 300 MHz ChargeGuard Compatibility Details
The Transmitter Solutions TRAEMP300MCD21V-C is the Gate Openers Unlimited catalog SKU for the Emperor transmitter identified by the manufacturer as model EMP300MCD21V-C. This is a traditional one-button visor-style fixed-code transmitter operating at 300 MHz with a 10-position DIP switch and ChargeGuard battery-status LED.
Transmitter Solutions specifically identifies the EMP300MCD21V-C as compatible with the Linear Multicode 3089. Manufacturer documentation also states that the transmitter is designed for 300 MHz DIP-switch receivers, including Multicode DIP-switch digital receivers.
What This Transmitter Does
The EMP300MCD21V-C sends one wireless 300 MHz command to a compatible fixed-code receiver. It is intended for applications where the receiver uses the matching 10-position DIP-switch coding format.
Programming is performed by setting the transmitter's 10 code switches to match the authorized code used by a functioning transmitter or compatible receiver. The transmitter provides 1,024 code combinations.
All Verified Compatibility
- Linear Multicode 3089.
- 300 MHz DIP-switch receivers using the compatible fixed-code format.
- Multicode DIP-switch digital receivers operating at 300 MHz.
- Gate, garage door, door, or similar control applications using a separately installed compatible 300 MHz DIP-switch receiver.
10-Position DIP Switch Compatibility
The EMP300MCD21V-C uses a 10-digit toggle code switch. The transmitter code must match the compatible receiver system. A remote operating at 300 MHz is not automatically compatible if it uses a different number of code switches or a different radio protocol.
Before ordering, open an existing authorized transmitter or inspect the receiver and count the physical switch positions. Verify 10 positions and 300 MHz operation.
ChargeGuard Battery Status LED
The ChargeGuard circuit uses the transmitter LED to indicate battery condition and expected transmitting signal level. The manufacturer manual identifies the following LED indications:
- Green LED - battery good and maximum transmitting signal.
- Yellow LED - battery approximately 50 percent expended and transmitting signal average.
- Red LED - battery approximately 75 percent expended and transmitting signal weak; battery replacement is suggested.
- No LED - battery dead.
ChargeGuard is a battery-status feature. A green LED does not prove receiver compatibility or confirm that the DIP-switch pattern is correct.
Similar Parts Are Not Automatically Interchangeable
The EMP300MCD21V is the related version identified by Transmitter Solutions as available without ChargeGuard. Do not assume the standard EMP300MCD21V includes the ChargeGuard battery-status LED used on EMP300MCD21V-C.
Other Emperor transmitters may use different frequencies, code-switch counts, button configurations, or manufacturer compatibility. A similar gray visor housing does not establish interchangeability.
A 310 MHz, 318 MHz, 390 MHz, or 433 MHz transmitter cannot be selected as a substitute for this model based only on appearance. The receiver frequency and coding system must match.
Features and Specifications
| Feature | Specification |
| Brand | Transmitter Solutions |
| Product Family | Emperor |
| Catalog SKU | TRAEMP300MCD21V-C |
| Manufacturer Model | EMP300MCD21V-C |
| Product Type | Wireless visor transmitter |
| Operating Frequency | 300 MHz |
| Number of Buttons | 1 |
| Button Color | Black |
| Case Color | Gray |
| Mounting Style | Visor model with clip slot |
| Code Switch Format | 10-position DIP/toggle code switch |
| Code Combinations | 1,024 |
| Battery Type | 1 x 9V battery |
| Battery Status Feature | ChargeGuard LED indicator |
| Operating Temperature | Official cut sheet lists -20 F to 85 F; older manufacturer manual lists -20 F to 100 F |
| Overall Dimensions | 2-3/8 x 3-1/2 x 3/4 inch |
| Weight | 3 oz |
| Verified Named Compatibility | Linear Multicode 3089 |
| Warranty | 2 years per manufacturer documentation |
Manufacturer Temperature Documentation Difference
The official EMP300MCD21V-C cut sheet lists an operating temperature range of -20 F to 85 F. The older manufacturer programming manual lists -20 F to 100 F. Because the official documents do not state the same upper temperature limit, use the current cut sheet specification when the application depends on a defined environmental rating and verify the current production revision when necessary.
Also Known As and Related Product References
- TRAEMP300MCD21V-C - Gate Openers Unlimited catalog SKU.
- EMP300MCD21V-C - Transmitter Solutions manufacturer model.
- Emperor 300MCD21V-C.
- EMP300MCD21V - related non-ChargeGuard version.
- Linear Multicode 3089 - manufacturer-identified compatible transmitter reference.
Package and Battery Check
The manufacturer specifies one 9V battery as the required battery type. Public manufacturer documentation reviewed for this model does not clearly state the retail package contents or confirm that a fresh replacement battery is included in every package. Confirm package contents when battery inclusion is important to the order.
Technician Note
The main ordering mistake with the EMP300MCD21V-C is matching the gray visor case or the 300 MHz frequency but not checking the 10-switch code format. Frequency alone is not enough. Count the switches in the existing remote or receiver and verify the receiver uses the compatible 300 MHz fixed-code DIP-switch system before ordering.
Before Ordering Checklist
- Confirm the receiver operates at 300 MHz.
- Verify the existing system uses fixed-code DIP-switch transmitters.
- Count 10 physical code-switch positions.
- Confirm Linear Multicode 3089 compatibility when replacing that transmitter model.
- Verify the exact EMP300MCD21V-C model when ChargeGuard is required.
- Do not confuse EMP300MCD21V-C with the non-ChargeGuard EMP300MCD21V.
- Check the existing authorized DIP-switch pattern for programming reference.
- Confirm that one-button operation matches the application.
- Confirm package contents if a supplied battery is required.
Programming and Service Notes
The manufacturer manual instructs the user to access the 10-digit toggle code switch through the bottom front cover and set the switches to match the code used by another functioning authorized transmitter or the compatible receiver. Each switch is placed in the ON or OFF position according to the system code.
After matching the code, reinstall the battery and cover and test the transmitter while the controlled gate or door is visible and the travel area is clear. If the transmitter LED does not light, check the 9V battery. If the LED lights but the receiver does not respond, verify the DIP-switch code and receiver compatibility. Reduced range may indicate a weak battery, receiver antenna trouble, or radio interference.
Professional Advisory
Do not bypass photo eyes, monitored safety edges, entrapment protection, door reversal systems, or operator safety circuits to correct a remote-control problem. If the receiver, gate operator, or garage door opener has damaged wiring or an unclear electrical or safety-circuit fault, have the system inspected by a qualified gate, garage door, or access control technician.
Product Questions and Answers
Is TRAEMP300MCD21V-C the same transmitter model as EMP300MCD21V-C?
TRAEMP300MCD21V-C is the supplied catalog SKU, while Transmitter Solutions identifies the Emperor transmitter itself as model EMP300MCD21V-C. Verify 300 MHz frequency and the 10-position DIP-switch format when replacing an older remote.
Is the EMP300MCD21V-C compatible with the Linear Multicode 3089?
Yes. Transmitter Solutions specifically identifies the EMP300MCD21V-C as compatible with the Linear Multicode 3089. Match the 10-position fixed-code DIP-switch pattern to the authorized system code.
Can the EMP300MCD21V-C work with any 300 MHz receiver?
Do not assume compatibility based on frequency alone. Manufacturer documentation identifies compatible 300 MHz DIP-switch receivers, including Multicode DIP-switch digital receivers. Verify that the receiver uses the matching fixed-code DIP-switch format.
How many DIP switches does the EMP300MCD21V-C use?
The EMP300MCD21V-C uses a 10-position DIP or toggle code switch and provides 1,024 code combinations. Count the switches on the existing authorized transmitter or receiver before ordering.
What does the ChargeGuard LED indicate on the EMP300MCD21V-C?
The manufacturer manual identifies green as battery good, yellow as approximately 50 percent expended, red as approximately 75 percent expended with battery replacement suggested, and no LED as a dead battery. The LED indication does not confirm receiver compatibility or correct DIP-switch programming.
Is EMP300MCD21V the same as EMP300MCD21V-C?
They are related transmitter models, but Transmitter Solutions identifies EMP300MCD21V as the version without ChargeGuard. Order EMP300MCD21V-C when the ChargeGuard battery-status LED feature is required.
What battery does the EMP300MCD21V-C use?
The transmitter uses one 9V battery. Manufacturer specifications identify the battery type, but the public documents reviewed do not clearly confirm battery inclusion in every retail package, so package contents should be confirmed when a supplied battery is required.
What should I check if the ChargeGuard LED lights but the gate or door does not operate?
Verify the 10-position DIP-switch pattern and confirm that the receiver is a compatible 300 MHz fixed-code DIP-switch system. If compatibility and coding are correct, the receiver, antenna, radio interference, or operator input may require diagnosis by a qualified technician.
