The U.S. Army seeks potential sources capable of manufacturing specific spare parts, including circuit card assemblies and a signal converter, for the ASN-128 Doppler Navigation System. This is a sources-sought notice for market research only and is not a solicitation for bids or proposals. The Government does not possess the technical data package for these parts and requests detailed capability information from manufacturers. Interested companies must submit their responses, including a completed contractor questionnaire, via email by January 30, 2026. No budget, performance location, or solicitation timeline is provided in this planning notice.