T8B08

SIGNALS AND EMISSIONS · Amateur satellite operation: Doppler shift, basic orbits, operating protocols, modulation mode selection, transmitter power considerations, telemetry, satellite tracking programs, beacons, uplink and downlink mode definitions, spin fading, definition of "LEO", setting uplink power

T8B08T8B →

What does it mean if a satellite is operating in U/V mode?

AThe satellite uplink is in the 15-meter band and the downlink is in the 10-meter band
BThe satellite uplink is in the 70-centimeter band and the downlink is in the 2-meter band
CThe satellite operates using ultraviolet frequencies
DThe satellite frequencies are usually variable

Why Satellite mode designations list the uplink band first and the downlink band second, using letter codes for the bands: U means UHF 70 centimeters (around 435 MHz) and V means VHF 2 meters (around 145 MHz). So U/V means you transmit up on 70 cm and listen down on 2 meters. This is the most common linear transponder arrangement on modern amateur satellites, including the ISS-style and AMSAT birds; the reverse, V/U, uses a 2 meter uplink and 70 cm downlink.

Watch out The 15 meter up, 10 meter down pairing describes the older HF mode A (sometimes shown as H/H letters), not U/V, and neither letter has anything to do with ultraviolet light or variable frequencies.

Up first, down second. U = UHF 70 cm, V = VHF 2 m. U/V: talk up on 440, listen down on 145.

HamSandwich explanation, first draft. The question and answers are the NCVEC text.

T8B08

The rest of T8B