MCM Electronics

RJ45 Cable Tester for RJ-45 and BNC By Tenma (72-9940) MCM Part #72-9940

2 stars 2 reviews
MSRP: $22.99
You Save: $15.00 (65 %)
This product currently has limited stock.

Easily test RJ-45 and BNC network cables. Features remote testing which allows you to test cables that are terminated at separate locations.

Specifications Top

  • Five bright LED’s confirm continuity on 4 wire pairs plus ground
  • Uses one 9V battery (not included)

Part Numbers
MCM Part #:72-9940
Tenma Part #:72-9940
Package Specifications & Dimensions
Weight:0.27 lbs.
RoHS Comp:No
Warranty:90 days
Need to Return?
Length:7.5 in.
Width:5.5 in.
Height:1.25 in.
Shipping Information
Extra Shipping Charge:No
Drop Ship:No

Product Reviews Top

  • by Command-com

    on 12/6/2014

    Product pictured is not what you get

    Overall: 1.5 out of 5

    There are so many issues, I hardly know where to start. Here are a few:

    1) Product CANNOT test a BNC cable by itself. You'll need a shorting device or terminating load to connect to the far end to test continuity. Instructions claim the BNC indicator is 2-color (Red + Green). It only lights green.

    2) Product does not match the picture in catalog. The main tester does NOT have LED's for each cable pair, so you will need both devices (Main tester and remote tester) to check an 8-conductor cable (UTP or STP)

    3) The instructions shipped with the device do not match the device - they match the picture. You'll have to figure out the correct steps on your own.

    4) The instructions printed on the label are accurate, but vague and very difficult to read. Think black letters printed on charcoal background. The example indicators (Dark green and black) are especially difficult to make out. You'll need your glasses and excellent light.

    5) The regular continuity test causes 4 LEDs on the remote device to illuminate in sequence - 1 for each pair. If the sequence is wrong, the wiring is wrong. If an LED fails to light, the pair is open or shorted. The main tester has a push-ON push-OFF button, so you can hook up the tester at one end, carry the remote tester to the other end, hook it up and get a reading.

    6) The GND test button is momentary contact, meaning 2 technicians are required to test installed shielded wiring - 1 to hold the button, and one to look at the indicators on the other end! When pressed, the GND LED lights in place of the 3 & 6 pair LED, causing the flashing sequence to seem to jump around. It is confusing at first, but it seems to work.

    7) The issue about the power switch being accidentally pressed mentioned in the previous review remains. I'd suggest you open the blister pack carefully, and use it to store the tester when not in use. This should solve the accidental turn-on problem

    For the tech who is willing to take the time to figure out how the device really works, and will use it often enough to remember all its quirks, this could be a handy gadget to have in his tool box. Don't forget to pack BNC shorting plug or terminating plug!

  • by djblair

    on 1/17/2014

    Works as advertised, but not ideal for the mobile techician.

    Overall: 2.5 out of 5
    Top 10 Contributor

    I've had this tester for many years, since the case was yellow in color. The device works 100% as advertised, and has held up well over the years. HOWEVER... The push on/off power switch is a huge problem. Just the slightest amount of pressure turns the device on, even through the protective soft case. This was a big problem when carrying in my tool bag, as the batteries were always dead when I needed it. A toggle on/off slide switch would have been a much wiser design decision. I went so far as to open the device, remove the hard plastic power button, and use a screwdriver to turn the item on and off.

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