137 MHz · VHF

Downlink

Pulling weather images out of the air with a homemade antenna and a twenty dollar radio. Pass schedules, station notes, and an honest log of what actually decoded.

Next passes

Satellite	AOS	Max elevation	Mode	Downlink
NOAA 19	19:42	71°	APT	137.1000
METEOR-M2 4	20:08	33°	LRPT	137.9000
NOAA 18	21:16	19°	APT	137.9125
NOAA 15	22:31	54°	APT	137.6200
METEOR-M2 3	23:47	42°	LRPT	137.1000

Times local. Anything under about twenty degrees is a waste of a recording here — the treeline eats the first and last two minutes and the rest arrives full of noise.

Station

Antenna: V-dipole, 120° included angle, elements cut for 137 MHz, roughly a metre above the flat roof
Feedline: 4 m of RG-58 with a choke of seven turns at the feedpoint
Receiver: RTL-SDR v3 with the bias tee off, sampling at 2.048 MS/s
Filtering: SAW filter inline — not optional within earshot of an FM transmitter
Decoding: Recorded to WAV on the pass, decoded afterwards rather than live

Reception notes

17 Sep 2026 · NOAA 19 · 71°

Cleanest pass of the month

Almost overhead, almost no noise. The coastline came through sharp enough to pick out individual inlets in the infrared channel. Fourteen minutes of usable signal, which is about as good as it gets from a fixed antenna.

14 Sep 2026 · METEOR-M2 4 · 33°

LRPT lock lost twice mid-pass

Digital modes fail differently — instead of degrading into static the image simply stops and resumes with a shifted line. Two dropouts, both near the horizon. Recovered most of it, but the seam is obvious.

9 Sep 2026 · station

Rebuilt the choke, noise floor down 4 dB

Common mode on the feedline was doing more damage than the local interference I had been blaming. Seven turns on a small ferrite, ten minutes of work, and the difference is visible on the waterfall before a pass even starts.