Linear/Nice documents MegaCode as a learned-code radio format operating at 318 MHz on its current MTR3 and MegaCode receiver products. Current MTR3 and MTS3 transmitters are designed to activate MegaCode receivers, while older MCT-3 hardware is also a MegaCode 318 MHz transmitter. Confirm that the installed opener or external receiver actually uses MegaCode before ordering; a Linear-branded dip-switch or older non-MegaCode receiver is a different compatibility branch.
What you are likely to notice
- You need a replacement remote for a Linear opener
- The opener or receiver is labeled MegaCode
- An old MCT-3/MTR3/MTS3 remote is present
- A separate external Linear receiver may be controlling the opener
Check these in order
1. Identify the active receiver format
Look for MegaCode on the motor-unit documentation or external receiver. Linear describes MegaCode receivers as learned-code devices rather than code-switch systems, so the receiver format is stronger evidence than transmitter shape.
2. Preserve the 318 MHz clue
Linear lists 318 MHz for current MTR3 and MegaCode receiver products. Frequency supports identification, but it should be paired with the MegaCode format because another 318 MHz product is not automatically compatible.
3. Match the current transmitter to MegaCode
MTR3 and MTS3 are current three-button MegaCode transmitter paths. MCT-3 is a documented MegaCode transmitter but is marked discontinued/limited availability, so replacement shopping should use a current manufacturer-supported transmitter where possible.
4. Treat external receivers as an override
Linear's MDR/U can add MegaCode capability to another garage-door operator. If an external receiver is wired to the opener, that receiver can determine remote compatibility even when the ceiling opener itself is another brand.
Why 318 MHz alone is not a compatibility answer
Linear's current MegaCode transmitter and receiver pages pair two facts: the radio operates at 318 MHz and the devices use the MegaCode learned-code format. Keep those facts together. A frequency match can help identify a radio family, but frequency by itself does not prove that two products share the same encoding, enrollment method or receiver logic.
This is especially important in an older garage where the motor unit, handheld remote and external receiver may have been installed in different years. Read the active receiver label before buying. If a separate receiver is wired to the opener, its protocol can matter more to the handheld remote than the brand name printed on the ceiling motor.
MCT-3 versus current MTR3/MTS3 paths
Nice/Linear still documents the MCT-3 as a 318 MHz MegaCode transmitter, but marks that product discontinued or available only while supplies last. That makes it useful identification evidence without making it the best default replacement target. Current MTR3 and MTS3 products are documented as MegaCode transmitters for up to three MegaCode receivers.
If an old MCT-3 is the only surviving clue, record its full label and confirm MegaCode at the active receiver. Then use the current manufacturer transmitter documentation rather than buying a visually similar used remote. Button count is mainly about how many supported receivers can be controlled; it does not change the required receiver protocol.
How an MDR/U receiver changes the diagnosis
Linear's MDR/U is specifically designed to add MegaCode radio capability to nearly any garage-door operator. That is a useful reminder that remote compatibility can be receiver-centric rather than motor-unit-centric. A non-Linear opener can legitimately be controlled by a Linear MegaCode remote when an MDR/U or another documented MegaCode receiver has been added.
Before declaring an opener's original receiver defective, look for a small add-on receiver and trace only the visible low-voltage connection. Do not open live electrical compartments. If an external receiver is present, preserve its model number in your notes and use that model as the primary remote-compatibility evidence.
Stop DIY troubleshooting when…
- The receiver uses DIP/code switches instead of MegaCode learn mode
- The only clue is remote shape or button count
- The opener/receiver frequency cannot be confirmed
- Internal receiver wiring or electrical service is required
Garage door springs, cables and a falling/unbalanced door can store or release dangerous force. Those are door-system problems, not just opener settings.
Common questions
Are all 318 MHz garage door remotes compatible with Linear MegaCode?
No. Nice/Linear documents MegaCode and 318 MHz together. Frequency alone is not enough to prove protocol compatibility.
Is MCT-3 still the best replacement to buy?
MCT-3 is useful legacy identification evidence, but Linear marks it discontinued/limited. Current MegaCode transmitters such as MTR3 or MTS3 are the safer manufacturer-supported starting point after receiver verification.
Can a Linear remote work on another opener brand?
Yes when a documented external MegaCode receiver such as MDR/U is controlling that opener. The active receiver, not the motor-unit logo, determines that radio path.
Should I erase all remotes before testing a replacement?
Not as a first step. Confirm protocol and follow the exact receiver programming instructions so working transmitter memory is not destroyed unnecessarily.
Manufacturer sources used
These links are the factual baseline for the diagnostic claims above. Model-specific manuals can supersede general guidance.