Black Box 1-800-316-7107

Helping you is our priority at Black Box.

We're committed to providing the best customer service in the industry. We're here for you, 24/7, 365.

We'll call you

A technical expert will call you shortly.

Submit Connecting call...

Call Us

Customer Sales & Service Support

Black Box Brand Product Support

IT Services & Voice Support

Send us a FAX


MicroRACK Micro NTU G.703 Card, 75-Ohm

A compact NTU for linking G.703 networks to RS-530 or X.21 lines.


Please call 877-877-2269 for a replacement product or part.
Extended Double Diamond™ Warranty Available (3 Additional Year)

Product Features

  • This MicroRACK card offers an ideal way to connect equipment with RS-530 or X.21 interfaces to G.703 networks.
  • Used as a modem for equipment links to a G.703 network, it sends unstructured, sync 2.048-Mbps data from a G.703/E1 network to a router, bridge, or mux.
  • Used as an interface converter, it accepts 75-ohm (dual-coax) G.703/E1 signals and converts them so RS-530 or X.21 equipment can read them.

Tech Specs

CE Approval Yes
Clocking G.703: Internal, external, network (receive loop)
Diagnostics Loopback
Indicators (5) LEDs: Power, Network, Master Clock, Loop, Loopback
Interface Network: G.703; Terminal: RS-530 (V.36/RS-422), X.21 on HD26
Power From the rack
Size 3.1"H x 5.4"W x 1"D (7.9 x 13.7 x 2.5 cm)
Speed Network: 2.048 Mbps; Terminal: 256 kbps, 512 kbps, 1.024 Mbps, 2.048 Mbps
Weight 1 lb. (0.5 kg)

This product works with:
  • MicroRACK (RM202, RM204, RM208, RM216)
    Questions? Contact our FREE Tech Support.

    * Technical specification weight is the unit weight. It is not the packaged shipping weight. For shipping weight, please contact Black Box customer service at 877-877-2269.

  • Warranty

    Double Diamond Warranty

    Extended 1 Year Warranty Available

    Protect your purchase with an additional 1 Year Double Diamond™ warranty!
    Cost: $37.49

    Extended 3 Year Warranty Available

    Protect your purchase with an additional 3 Year Double Diamond™ warranty!
    Cost: $74.97


    Double Diamond™ Warranty (Standard)

    Take the risk out of equipment purchases with the Double Diamond™ Warranty from Black Box Network Services.

    The Double Diamond Warranty is our warranty that protects your Black Box® brand products* from accidental damage, including drops, water, and power surges.

    The MicroRACK Micro NTU G.703 Card, 75-Ohm comes with a standard 1 Year Double Diamond™ Warranty (Standard) already included.

    During the warranty period, Black Box Network Services will repair or replace your damaged equipment within one week of receipt at NO CHARGE!*

    Plus, get an Extended Double Diamond Warranty.

    You can also extend your warranty or protect a previously purchased Black Box® brand product** for an additional year—for only 10% of the purchase price! Or, extend your coverage for a full three years for only 20% of the purchase price!

    Ordering an extended warranty is easy: When viewing a product in your shopping cart, just select the one or three years of additional coverage in the dropdown menu under “Warranty Options.” For details, contact Customer Service at 724-746-5500.

    * Warranty subject to certain exclusions and limitations ** Certain products may not be eligible.

    What’s more, we also have a 45-day return policy. Simply call Customer Service for a Return Authorization (RA) number, return your product in new condition and in the original package, and receive a full refund.