karn@eagle.UUCP (05/29/83)
28 MAY 83
INTERCONTINENTAL PACKET RADIO TESTS SUCCESSFUL
At approximately 23:00 UTC on 27 May, a successful digital packet
radio QSO was held between Tom Clark, W3IWI in Maryland and Ian
Ashley, ZL1AOX near Auckland, New Zealand on 28 MHz. This 13850
km path represents the longest distance yet bridged using packet
radio. Both stations were using the Terminal Node Controller
(TNC) developed by the Tucson Amateur Packet Radio group in
conjunction with home built S-100 computers. The QSO used Freq
uency Shift Keying (FSK) techniques at a data rate of 1200 baud.
Although propogation conditions were marginal, data exchanges
consisted of "beacon" transmissions and two-way connection ack
nowledgements using the amateur AX.25 HDLC protocol; with this
protocol messages are sent repeatedly until they are successfully
acknowledged by the other station.
Also participating in the test was Bob Diersing, N5AHD in Corpus
Christi, Texas; W3IWI and N5AHD have held several successful
packet radio QSO's. N5AHD monitored the beacon and text
transmissions from both W3IWI and ZL1AOX.
All three stations involved are affiliated with AMSAT and have
been experimenting with high speed digital transmissions in
anticipation of conducting similar activities with AMSAT's Phase-
3B satellite due to be launched in the near future, and with
AMSAT's PACSAT packet radio satellite now being designed.