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← Archive Blueprint Signal Noise · Joel Kirby · Bristol, 2026 E7 · The Fractured
Engineering Schematic

Unit J.K.

Harmonic detector-amplifier. Bristol basement, 2026. Four sheets. These drawings were produced from memory during the Ceres Station period — Kirby's original notebook having been misplaced during the second displacement.

Sheet 1 — External ViewSheet 2 — Coil AssemblySheet 3 — Signal PathSheet 4 — Annotations
DRAWING NO.JK-001-01
TITLEUNIT J.K. — EXTERNAL VIEW
SCALE1:8 APPROX
DRAWN BYJ. KIRBY
DATE2026 — FROM MEMORY, CERES, 2157
SHEET1 OF 4
280mm 180mm SIGNAL INDICATOR ARRAY (×3) HANDSET PORT OUTPUT PORT charge indicator reads ~30% on activation day — wasn't sure that was enough vents never got warm — thought that was wrong
DRAWING NO.JK-001-02
TITLEUNIT J.K. — PRIMARY COIL ASSEMBLY
SCALE1:3 APPROX
DRAWN BYJ. KIRBY
DATE2026 — FROM MEMORY, CERES, 2157
SHEET2 OF 4
240mm IN OUT 16 turns, 0.8mm copper — was going to do 20 but ran out ferrite core from old transformer (skip)
DRAWING NO.JK-001-03
TITLEUNIT J.K. — SIGNAL PATH / SCHEMATIC
SCALENOT TO SCALE
DRAWN BYJ. KIRBY
DATE2026 — FROM MEMORY, CERES, 2157
SHEET3 OF 4
INPUT ANTENNA PRE AMP 1420 MHz H.DET OUTPUT PORT not sure this is the right symbol for "harmonic detector" the signal doesn't come from the antenna — but it comes out here I don't understand what this component does
DRAWING NO.JK-001-04
TITLEUNIT J.K. — CONSTRUCTION NOTES
SCALEN/A
DRAWN BYJ. KIRBY
DATECERES STATION, 2157
SHEET4 OF 4

Construction Notes — Joel Kirby — Ceres Station 2157 — written from memory

HOUSINGAluminium project box, 280×180×60mm. Purchased from Maplin, Bristol. Spray-painted black.

COIL16-turn air-core coil, 0.8mm enamelled copper wire. Former: PVC pipe, 35mm diameter. Ferrite rod through centre, recovered from a dead AM radio.

PRE-AMPLNA board, 30–3800MHz, bought online. Powered by USB 5V rail.

FILTERHelical bandpass filter. 1420MHz. Centre frequency tunable. Built from drawings in a 1978 ARRL handbook.

DETECTORI thought it was an envelope detector. I'm not sure what it actually is. Output: 0–5V DC proportional to signal intensity. The proportionality function is non-standard.

POWER9V DC input. Linear PSU — switched-mode creates too much noise on 1420MHz band.

OUTPUTBNC port, 50-ohm. Also: 3.5mm jack for headphone monitoring. The headphone output produces a tone I have not been able to explain.

INDICATORSThree 5mm LEDs: POWER (green), SIGNAL (yellow), THRESHOLD (red). The threshold LED has never been off.

NOTE AThe device activates before power is applied. I have tested this twelve times. I do not know what power source it is using when unplugged.

Dad says to write down what I don't understand as well as what I do. This is the what I don't understand list.

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