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Linear / Accessory reference

Linear MDR/U plug-in radio receiver

MDR/U identifies a plug-in radio receiver. The cited source supports only the exact facts and relationships shown; other equipment pairings remain unverified.

US source scopeUpdated 2026-09-11Independent Anderson reference

Match the whole number.

Manufacturer identifier: MDR/U. Keep every character when comparing it with your label or paperwork. A similar number does not establish the same component.

Documented alternate identifiers

  • MDR-U
  • DNR00100
    • mdru pageDescription, Part Number · checked 2026-09-11 · Nice North America LLC
Values apply to the exact identifier and scope in the cited source.
Component functionPlug-in radio receiver
Receiver memory10 transmitter codes
OutputNormally open dry-contact relay
Contact closure duration0.5 seconds
Literature input power110 VAC +/- 10%, 60 Hz
Channel count1 channel
  • mdru pageDescription, first sentence · checked 2026-09-11 · Nice North America LLC
Radio frequency318 MHz
  • mdru pageFeatures, RF frequency · checked 2026-09-11 · Nice North America LLC
Radio formatMegaCode
  • mdru pageDescription and Features, Codes · checked 2026-09-11 · Nice North America LLC
Input power reviewThe literature gives 110 VAC +/- 10%, 60 Hz; manual 220675 A contains both 110 VAC and 120 VAC wording. Unit-label and electrical confirmation remain required.

Documented fitment & exclusions

Read the exact equipment or receiver, market, production and variant limits in every row. An omitted pairing has not been verified by this reference.

A receiver radio pairing applies only to the listed devices and source conditions. It does not establish the receiver’s suitability for an installed opener or compatibility through another device.

Source statements and their exact conditions. Use the checker below to compare equipment or a receiver.
Equipment or receiver / relationshipEvidence and conditions
ACT-31B

Documented compatibility

From ACT-31B to MDR/U.

ACT-31B is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-31C

Documented compatibility

From ACT-31C to MDR/U.

ACT-31C is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-31D

Documented compatibility

From ACT-31D to MDR/U.

ACT-31D is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-31DH

Documented compatibility

From ACT-31DH to MDR/U.

ACT-31DH is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-31DHC

Documented compatibility

From ACT-31DHC to MDR/U.

ACT-31DHC is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-34B

Documented compatibility

From ACT-34B to MDR/U.

ACT-34B is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-34C

Documented compatibility

From ACT-34C to MDR/U.

ACT-34C is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-34D

Documented compatibility

From ACT-34D to MDR/U.

ACT-34D is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-34DH

Documented compatibility

From ACT-34DH to MDR/U.

ACT-34DH is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control
ACT-34DHC

Documented compatibility

From ACT-34DHC to MDR/U.

ACT-34DHC is documented for MDR/U in MegaCode radio-control use. MegaCode radio transmitter function only. The chart's proximity-reader entries and bold formatting do not establish proximity-reader functionality in these garage operators. Enroll the transmitter code using the exact equipment instructions; custom and factory coding configurations remain distinct. This pairing concerns radio reception by MDR/U, not every opener connected downstream. Code enrollment and installation follow the exact equipment instructions; this does not verify an installed system.

Applies only within this source scope
  • Market: US
  • comparison-function: MegaCode radio control

Direct replacement paths

No direct successor for MDR/U is verified in this reference.

Earlier numbers this item is listed to replace

  • MDR/U replaces MDR only within the following source scope.

    MDR/U is documented as replacing MDR within the receiver/input/power scope shown.

    Applies only within this source scope
    • Market: US
    • operator-input: normally-open dry-contact pushbutton input
    • receiver-power: 110 VAC +/- 10%, 60 Hz
    • Replacement concerns the external radio receiver arrangement described by the source; it does not identify every operator model as compatible.
    • MDR/U supplies its own mains-powered receiver instead of the MDR arrangement with an external transformer. Exact equipment input and electrical suitability need confirmation.
    • Source manual 220675 A uses both 120 VAC and 110 VAC wording. The electrical condition preserves the literature's 110 VAC +/-10%, 60 Hz rating; check the unit label and qualified installation requirements.
    • No reverse interchangeability, automatic replacement chain, or receiver-disabling procedure is asserted.
    • MDR/U receiver literaturePage 1, second body paragraph contrasting MDR with external transformer and MDR/U · checked 2026-09-11 · 221931B · Linear LLC
    • MDR-U receiver installation instructionsPage 1 Product Description and power wording, both 110 VAC and 120 VAC references · checked 2026-09-11 · 220675 A · Linear Corporation

A direct replacement statement does not establish reverse interchangeability, a kit equivalent or a later replacement chain.

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Selected: MDR/U · Read its reference. Selection identifies a record; it does not confirm fitment.

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A receiver radio pairing applies to the exact listed pair. It does not establish the receiver’s suitability for your installed opener or compatibility through another device.

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Recall references

No recall reference is included for this identifier in the published dataset. This is not a safety clearance or proof that no recall exists.

Sources & scope

  1. ACT transmitter and TRANS PROX compatibility chartLinear LLC · US · checked 2026-09-11 · 232495 B
  2. MDR-U receiver installation instructionsLinear Corporation · US · checked 2026-09-11 · 220675 A
  3. MDR/U receiver literatureLinear LLC · US · checked 2026-09-11 · 221931B
  4. mdru pageNice North America LLC · US · checked 2026-09-11

Anderson prepared this reference from the listed evidence. Source statements are not an Anderson installation inspection or independent product test. Official documents stay on their publisher’s website.

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