Five returns expand from a single impulse, cross, and resolve without measurable loss. No corresponding source appears in the outbound record.
- Holding
- ECHO-BLOOM
- Access
- Optical study permitted
- Handling
- Do not normalize
Fundamental Acoustics LaboratoriesResearch Records Office · signal preservation
PSC–1044 / CIRCUIT RETURNPreservation exception · active
Delayed return / open
A disconnected 1978 test circuit returned its signal forty-eight years late.
The incoming cadence matches the original paper master. The return also contains room tone that was not present when the line was closed.
Associated physical holdings
Circuit B / BASE-221
The circuit remains isolated under Research Records Office authority.