A Short List Of PacSats:

A Short Note to PacSat operators:

We would welcome any personal observations on operating these satellites!

Satellite Uplink Down Link

UO-11 145.825,435.025,2401.5

UO-22 145.900 435.12

KO-23 145.85/.90 435.175

KO-25 145.87/.98 435.175,436.5

AO-16 145.9/.92/.96 437.026,437.051,2401.143

DO-17 145.825,145.824,2401.22

WO-18 1265.00 437.075,437.125

LO-19 145.84/.86/.88/.90 437.153,437.125,437.125

IO-26 145.875/.90/.925/.95 435.87,435.82


9600 Baud Packet Satellites

UO-22, KO-23 and KO-25

UoSAT-OSCAR-22 (UO-22)

Built by: University of Surrey in Guildford, Surrey, England

NASA ID: 21575

Launched: July 17, 1991

Payloads: --Earth Imaging System using charge coupled camera
--9600 bps AX.25 protocol store-and-forward packet system

Orbit: Circular, 98 degree inclination, 770 km altitude, 100 minute period

Mode J: Uplink 1=145.900 FM
Uplink 2=145.975 FM
Downlink 1=435.120 FM

KITSAT-OSCAR-23 (KO-23)

Built by: Korean Advanced Institute of Science and Technology (KAIST)

NASA ID: 22077

Launched: August 10, 1992

Payloads: --high resolution Earth Imaging Camera System
--Digital Signal Processing Experiment
--Cosmic Ray Experiment
--9600 bps AX.25 protocol store-and-forward packet system

Orbit: Circular, 66 degree inclination, 1515 km altitude, 112 minute period

Mode J: Uplink 1=145.900 FM
Uplink 2=145.850 FM
Downlink 1=435.175 FM

KITSAT-OSCAR-25 (KO-25)

Built by: Korean Advanced Institute of Science and Technology (KAIST)

NASA ID: 22828

Launched: September 26, 1993

Payloads: --high resolution Earth Imaging Camera System
--Digital Signal Processing Experiment
--Infrared Sensor Experiment
--Low Energy Electron Detector
--9600 bps AX.25 protocol store-and-forward packet system

Orbit: Circular, 98 degree inclination, 800 km altitude, 101 minute period

Mode J: Uplink 1=145.870 FM
Uplink 2=145.980 FM
Downlink 1=436.500 FM
Downlink 2=435.175 FM

Overview

The primary purpose of UO-22, KO-23 and KO-25 is to provide store-and-forward digital communications using AX.25 packet radio "Pacsat Broadcast Protocol." All three carry high resolution cameras for Earth Imaging Systems (EIS), with the images digitized and stored for later processing and transmission over the downlink transmitter. UO-22 is commonly used as the satellite gateway for a global network of terrestrial ground stations, moving large amounts of packet radio traffic around the world in a short time period.

Hardware Requirements

Hardware requirements for reliable access to the 9600 baud satellites include a 9600 baud packet radio modem (capable of operating in the KISS mode, full duplex), a pair of high-gain directional antennas for 2 meters and 70 cm, and rotators allowing both azimuth and elevation control. A mast mounted pre-amplifier for the 70 cm downlink also helps. However, many stations have successfully used only fixed omnidirectional antennas, including j-poles and eggbeaters. Others have started by using a rotator for azimuth control only, fixing directional antennas at 25 degrees or so of elevation! The Yaesu G-5400B az-ele rotator combination appears to the most frequently used. Rotator control and radio frequency control, including Doppler shift, are accomplished by such devices as Kansas City Tracker with Tuner, SatTrack and TrakBox.

A 2 meter uplink transmitter and a 70 cm downlink receiver are required, both modified for 9600 baud operation. Modification notes are readily available, and the Yaesu FT-736R (most popular), Yaesu FT-726R and Kenwood TS-790A dual-band transceivers are all commonly used. Other radios in use include the Kenwood TS-711/TS-811 pair, Icom IC-275/IC-475 pair, and Icom IC-820H, to name just a few. A 2 meter amplifier is not required.

Software

Terminal software such as PB, PG, PHS, PFHADD and Windows Satellite Program (WiSP) are used for all the packet satellites, and allow access to the file server and mailbox aboard the satellites. Text, binary and image files may all be uploaded and downloaded.

WiSP, written by Chris Jackson, ZL2TPO/G7UPN, is an integrated suite of Windows programs which completely automate a groundstation for operation on all of the packet satellites, including the 9600 baud birds. WiSP includes the broadcast protocol used for downloading files and the connected protocol used for uplinking files, plus utility functions, satellite tracking and scheduling, integration with tracking and tuning packages, and more.

WiSP and other satellite software is available through AMSAT®-NA. Check out their homepage at http://www.amsat.org, available as a link on our previous page.

Whether you use a Windows program or a set of DOS programs, the easiest way to get started is to find another ham with a similar set up, and start from a copy of his or her initialization or configuration files.

Questions?

Questions about 9600 baud packet satellite operation, in particular on the use of WiSP, may be addressed to Bill Beach AL7MM in Fort Collins at [email protected], or by calling him at (970) 224-1958.

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