Ruggedized Field Radio Increases Reliability and Uptime

For today’s military, information is key to successful missions. And communication is only as good as the weakest link in the chain. That’s why, when the “go to” field radio was sustaining regular damage to the power and charging cable, the supplier called on Interconnect Solutions Company (ISC) as the experts in ruggedized connectivity to address the problem.

The Initial Findings and a Plan Emerges

Starting with an in-depth failure analysis, the engineers at ISC were able to pinpoint at least two specific areas of high stress leading to connection failure. These are denoted in the accompanying figure by the letters (A) and (B) (Refer to Figure 1 Radio Connector Highlighting Critical Areas). Their solutions would require custom overmolded connectors so they needed precise dimensions. Using their reverse-engineering capabilities they were able to duplicate the critical dimensions in a CAD format. From there they could produce go/no-go gauges for completed assemblies and validate them against their CAD model and the actual parts. This allowed them to reliably test prototypes and ultimately develop custom overmold tooling to secure these areas and relieve the stresses.

During this “discovery phase” and the development of an improved design, the engineers at ISC also realized that they could make the power interconnect a little more streamlined as well, thereby reducing the chances of the cable snagging and overstressing the connections. This is marked with the letter (C) in the accompanying figure. Connector stress leading to failure could not only be ruggedized but the magnitude of that stress could also be reduced, thus improving the initial design in two ways.

Build and Testing of Prototypes

With a clear path forward, ISC was ready to produce the initial prototypes for field testing by the customer. As a vertically integrated manufacturer, ISC has the benefit of producing its own connector overmolds in-house and they have total control of the quality of the finished goods. This ensures material compatibility with the existing design and retention of the original product specifications.

It was decided to make an initial small lot pre-production run of about a dozen pieces that were shipped to the customer and were field-tested for a period of several weeks. This was a critical part of the overall program since it is nearly impossible to simulate the connection forces that one would see in the field, through a series of shock and/or vibration tests. There are just too many variables and the actual stresses may vary widely due to weather conditions, equipment being worn by the soldier, and the level of activity.

Once the initial testing phase was successfully completed, it was clear that the ISC design was a significant improvement over the initial design as there was a significant reduction in field failures. At the same time, it also highlighted that one of the connector stress points was receiving higher than expected stress due to the geometry of an internal PCB connection. By using a fast-curing epoxy encapsulant at that junction, not only did it beef up the PCB connection, it provided an additional layer of sealing against the elements and also helped improve the security of that PCB assembly. From the initial contact to a finished, validated solution took only five months.

An Unexpected Improvement Opportunity Arises

Before closing the door on this story, the customer realized that ISC’s capabilities would allow them to solve a separate and unrelated problem with this same piece of radio equipment. When not connected to the power cable, the connector was exposed to the elements. A simple solution would be a dust cover with a retention wire for the connection point denoted as (A) in the accompanying photo. However, there were no off-the-shelf solutions available. Given ISC’s ability to quickly develop their own molded parts, it was a natural extension of the project to include this dust cap. The customer contracted for this additional part as well.

With a much more practical and reliable radio for field use, this customer was able to use a lot of the advantages that ISC brings to their customers; prior experience with their type of requirements experienced engineers, and vertical integration for fast prototyping. All played a part in the successful completion of this project and the improved uptime for secure communications in critical situations.