P300H P300 Series Modem Installation and Operating Handbook Page 24
[Viterbi, rate ½, ¾, or , k = 7 to IESS 308/309, 3 bit soft decision
decoding]
[Sequential rate ½, ¾, or to IESS 312, 2 bit soft decision decodi ng]
Reed-Solomon outer FEC [Concatenated Reed Solom on outer codec to IESS 308/310] [Optional
variable code rate]
Reed-Solomon, Turbo, T CM, Viterbi, & Sequential are independent FEC options, all
may be fitted simultaneously.
Scrambling
IBS/SMS Synchronised to framing, per IESS 309
IDR & Closed Net With RS Coding: synchronised to RS overhead.
No RS Coding, non Turbo: V.35 self synchronising.
No RS Coding, Turbo: Synchronous 2 - 1 (sync to TPC b lock alig nment).
12
Closed Net plus ESC 32kbps or above, synchronised to ESC overhead. Less than 32kbps, as
per Closed Network.
V.35 scrambler has CCITT, INTELSAT, `FDC` & `Linkabit `modes
IF Ports BNC female, 50 & 75 . Return loss 18dB typical.
External reference Clocking only: 1kHz-10MHz in 1kHz steps (See Stat ion Reference).
Clocking & Frequency: 10MHz, 0dBm ± 1dB
Modulator Specifications
Output Power Level P300: 0 to -25dBm continuously variable in 0.1dB steps f rom fron t panel
or via remote control
P310: -5 to -30dBm continuously variable in 0.1dB steps fro m front panel
or via remote control
Output Level Stability ±0.5dB at 25 C ±10 C
Transmit Filtering 6th order Butterworth, aperture and group delay equalised, INTELSAT
IESS compliant
Filter Implementation 257 tap FIR digital filter
Occupied Bandwidth 1.2 times symbol rate
Recommended 1.4 times symbol rate
Channel Spacing
Phase and Amplitude ± 2 degrees, ± 0.2dB, max
Accuracy
Carrier Suppression -30dBc, min.
Output Phase Noise <1.0 degrees RMS double sided, 100Hz to 100kHz
Output Frequency Stability As per internal reference from 0 C to 50 C (See Internal Reference
below)