KFX 4 Relay Board 5 and 8 button Key Fob


Using two sets of KFX 4 relay board with KFX receiver, antenna extension wire ( running from indoors to outdoors ~ 15 feet ) and 5 button fobs, I have noticed well under 300’ of operation. I have since upgraded to the 8 button Long Range fobs, with moderately improved range. While testing these 8 button LR fobs, suddenly one of the sets loses all range, and only works when fob is within a few feet of antenna. Tried with multiple fobs, same result. Also took out the antenna extension wire, same result.

I ordered and received another KFX Module, and I will be testing with this replacement module, hoping to get the range back.

I have ensured that there is no metal touching anything in the equation, and have powered down the units when making any hardware changes ( removing extension, etc )

I would like to send the original KFX unit in for examination and replacement. These have been in service for 2 months, and haven’t been performing well - generally speaking - with respect to advertised range, and have generated many complaints from my customer…

please advise of any testing measures I can take, as well as the process for returning unit for warranty repair.


The sudden loss of range sounds like a bad antenna connection. You can check that the antenna is fully seated and make sure the mounting nut is not preventing a full connection to the antenna. Its also possible that it is a damaged communications module or regulator on the board.

The poor performing wireless could be a result of interference induced over the antenna extension or just present on the wireless band on location in the facility.

You can submit an RMA request at this link: NCD Login - NCD.io

The standard testing procedure is to remove all accessories such as extensions, power up the board with the antenna connected directly to the KFX module. Then test the line of sight range of the modules without any obstructions.