RTTY AMTOR Metres and 13 Centimetres—No Transpon- Ders

1989 REFERENCE SECTION Amateur Satellite Frequency Guide UoSAT OSCAR—9 Beacons on 40 metres, 20 metres, 15 metres, 10 metres, 2 metres, 70 centi- RTTY AMTOR metres and 13 centimetres—no transpon- ders. Frequency Shift 2M Beacon 145.825 MHz (P) The Standard amateur Frequency shift for RTTY is 170 Hz. 70 cm Beacon 435.025 MHz (S) The Standard international Frequency shift for AMTOR is 170 Hz. The 2M & 70cm beacons carry primarily It can be obtained by two different methods:— 1200 baud ASCII 7 (or 8) bit telemetry & (a) By using the Inbuilt Frequency Shift Keying (FSK) method, which is found on H.F. bulletins using Kansas City tonesttf 1200 only transceivers and is usually a TTL input. & 2400 Hz. (b) By injecting the appropriate audio tones Into the microphone circuit. The tone pairs (Propagation Study Experiments) used in Australia are 2125 HE for the Mark tone and 2295 Hz for the SPACE tone. Commercial stations use various shifts on RTTY, but the most common are 170, 425 40M Beacon 7.050 MHz and 850 Hz shifts. 20M Beacon 14.002 MHz 15M Beacon 21.002 MHz Standard Speeds 10M Beacon 29.502 MHz The standard International speed for amateur RTTY stations is 45 Baud (or 60 words per SHF Beacon 2401 MHz minute). SHF Beacon 10470 MHz Some countries use 50 Baud (or 66 words per minute) internally as do some local VK The propagation study beacons transmit amateur Sunday broadcasts. Commercial traffic users have various speeds, but the main either morse code or a steady carrier. The ones used are 50, 57, 75 and 110 Baud. 2401 MHz beacon can also carry the stan- The speed for AMTOR Is 100 Baud. This speed is laid down In the internationally agreed dard telemetry format. CCIR 476-4) recommendation and is used by amateurs, ships, Interpol, embassies and various other commercial stations etc. UoSAT OSCAR—11 Beacons on 40 metres, 20 metres, 15 Calling and Net Frequencies metres, 10 metres, 2 metres, 70 centimetres and 13 centimetres—no transpon- RTTY AMTOR ders. 1.825 MHz call 1.825 MHz call 3.545MHz call, net, bet 3.545 MHz call, net 2M Beacon 145.826 MHz (P) 3.630 MHz call 3.630 MHz call 70cm Beacon 435.025 MHz (S) 7.045 MHz call, net, bet 7.045 MHz call, net, bbs 13cm Beacon 2401.5 MHz (S) 10.145 MHz call 10.145 MHz call The 2M, 70cm & 13cm beacons carry 14.090 MHz call, net, bet 14.075 MHz call, bbs primarily 1200 (or 4800) baud ASCII 7 (or 18.100 MHz call 18.100 MHz call 8) bit telemetry & bulletins using Kansas 21.090 MHz call, net 21.075 MHz call, net, bbs City tones of 1200 & 2400 Hz. 21.125 MHz call 21.125 MHz call AMSAT OSCAR—10 24.920 MHz call 24.920 MHz call 28.090 MHz call, net 28.075 MHz call, net Due to radiation damage to the Onboard 52.075 MHz call 52.075 MHz call Computer memory the Mode Ltransponder 146.600 MHz call, net, bet 146.600 MHz call, net & beacons are no longer active. However, 146.675 MHz call, net, bet, bbs, rptr 146.675 MHz call, rptr the Mode B transponder and beacons 432.075 MHz call 432.075 MHz call continue to operate when there is sufficient 1,252.1 MHz call 1,252.1 MHz call solar illumination on the solar panels. Mode B Transponder HF Mailboxes (AMTOR) Uplink Passband The days of RTTY mailboxes were numbered when AMTOR first appeared on the scene in later 70s. Below is a list of MAJOR AMTOR mailboxes and whether or not they support the 435.027 - 435.179 MHz new APLINK system. APLINK is the new forwarding method for AMTOR to Packet or Packet Downlink Passband to AMTOR mailboxes. All mailboxes listed below are 24Hr per day systems. 145.977 -145.825 MHz Country Callsign SELCAL Frequency Other Information The transponder is linear and inverting, i.e. LSB on the uplink results In USB on the Australia VK2AGE VAGE 7.045 MHz downlink, and the translation equation is: 14.073 MHz Listens for 12 14.074 MHz seconds on each freq. Downlink frequency = 581.004 — Uplink 14.075 MHz and has APLINK Frequency = +/- Doppler Shift 14.076 MHz facilities. The General Beacon is on 145.810 MHz 14.077 MHZ and the Engineering Beacon is on U.SJ*. WA8DRZ WDRZ 14.072.5 MHz Listens for 12 145.987 MHz. Due to the OBC memory 14.073.5 MHz seconds on each freq. failure the General Beacon only transmits 14.076.5 MHz and has APLINK Continued next page 14.075.5 MHz facilities. Page 40 — AMATEUR RADIO, February 1989 .

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