The original QuadLN was born of a collaboration between Duncan McRee of Tam Valley Depot and Robin Becker of N3IX Engineering to create a new Tam Valley Depot LocoNet® stationary decoder with the features of the existing QuadPic 4 servo decoder. Robin made the new QuadLN product field-upgradable and began steadily adding features. After Duncan updated the hardware to support further enhancements and Robin upgraded the software to support up to 8 servos, the original QuadLN became the QuadLN_S. After that the product family vision began to take shape. First came the Signal add-on board and later the Detector add-on board, allowing the QuadLN_S to fully support an OS / Control Point. To accompany each new board, Robin added new features maximizing the utility and value of the system. The innovation goes on to this day – the latest upgrade enables one QuadLN_S to support up to 16 servos.


Duncan was diagnosed with stage IV cancer in 2021 but fortunately he is now in remission thanks to amazing advances in medicine. At the time of his diagnosis Duncan decided to end manufacture and sales of the QuadLN_S by Tam Valley Depot. He passed the QuadLN_S product family over to Robin, and since then N3IX Engineering has handled manufacture and sale of the QuadLN_S family.


Since the beginning Robin has provided the customer support for the QuadLN products. He is committed to the QuadLN_S system and works tirelessly to help users achieve their model railroad control goals. Robin uses the entire family of products on his own layout.


We try to maintain inventory and ship orders quickly. Sometimes supply chain challenges result in delays, and we will keep you updated if this happens. We set the basic shipping charge as close to actual cost as possible. Orders are shipped using USPS or UPS. If you would like to add insurance or make other shipping arrangements, please contact us prior to placing your order.

Current Domestic Shipping Rates

Order AmountShipping ChargeCarrier
Under $125$6.00USPS or UPS
$125 and upFREEUSPS or UPS

Orders shipped to non-US addresses

We do our best to provide the appropriate customs declarations to the shipping company. Once the order is shipped, the buyer has full responsibility for all costs, import regulation compliance and other risks, including but not limited to duty, customs charges, taxes and shipping charges for a returned shipment.

If no shipping method is available during checkout, please contact us before placing your order.

Other Information


All electronics boards manufactured by N3IX Engineering are warranted against defects in manufacturing and/or failure of the board through no fault of the customer for one year after the date of sale.  This warranty does not cover boards modified by the user or boards damaged by the customer through misuse as determined solely by N3IX Engineering.  Customer is responsible for the cost of returning the board. Customer must contact N3IX Engineering prior to returning any board for repair or replacement.

Prices and Website Accuracy

N3IX Engineering reserves the right to change prices at any time.  We have done our best to ensure that all information and pricing presented is accurate, however N3IX Engineering reserves the right to correct any errors or omissions.

FCC Information

The QuadLN_S has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC rules. 

LocoNet Licensee

N3IX Engineering is a Digitrax LocoNet Licensee. 


Electronic products in general contain some level of substances identified by Prop 65 and therefore we state for your information that our products may expose you to chemicals which are known to the State of California to cause cancer and birth defects or other reproductive harm.  For more information go to www.P65Warnings.ca.gov.


N3IX Engineering LLC
2878 Copley Ave
San Diego CA 92116