Page 248 - Satellite Communications, Fourth Edition

228 Chapter Seven

Figure 7.23 INTELSAT V Atlantic satellite transmit capabilities. (Note: The 14/11-GHz
spot beams are steerable and may be moved to meet traffic requirements as they develop.)
(Courtesy of Intelsat Document BG-28-72E M/6/77, with permission.)

spacecraft series. These satellites had a predicted mission life of 9 years,
Morelos-A being retired in 1994, and Morelos-B was scheduled to remain
in operation until 1998. The payload carried on Morelos illustrates what
is referred to as a hybrid,or dual-band, payload because it carried
C-band and K-band transponders. In the C band, Morelos provided 12
narrowband channels, each 36-MHz wide, and 6 wideband channels,
each 72-MHz wide. In the K band it provided four channels, each 108-
MHz wide. The 36-MHz channels used 7-W TWTAs with 14-for-12
redundancy. This method of stating redundancy simply means that 12
redundant units are available for 14 in-service units. The 72-MHz chan-
nels used 10.5-W TWTAs with 8-for-6 redundancy.
The four K-band repeaters used six 20-W TWTAs with 6-for-4 redun-
dancy. The receivers were solid-state designs, with a 4-for-2 redundancy
for the C-band receivers and 2-for-1 redundancy for the K-band
receivers.