jul 21 2002
Nytt schema frn den 16 juli.
Information frn AMSAT-UK enligt nedan:
Effective this 765, on all days except Wednesday, the S2/K-Tx beacon only and passband segments are active again for testing. Note that the beacon only session (no passband) for S2 and K Tx s is MA 116-120, and the beacon + passband session is MA 120-128. As before, on Wednesday, the V-Rx along with L-band Rx s are connected to the passband from MA 120-128.
There s been some RUDAK issues too. Assi (I didn t know he was working on it) said:
The AO40 RUDAK team uploaded test code to one of the DSPs. This code generates a carrier at around 2401.625MHz ( doppler). The intent of this code is to help users do a ZR0 type experiment and test just how good their S-Band receive station is. The program generates a clean carrier at full RUDAK power, and then starts decreasing power in 3dB steps, all the way down to -30dB. One full cycle is 30 seconds. The resulting pattern is a sawtooth, and it is active between MA128 and MA160.
The code is new, and needs to be debugged. We would appreciate if some of you could record a wav file of the signal in SSB. If you can do so, please set your receiver so a clean tone is heard, and then record for at least 2 full minutes. During the recording don t update the frequency or mode so receiver phase modulation is not introduced. Once we get this code working, we will extend the period. If you can do this, please send Assi a zipped file emailed to firstname.lastname@example.org
There were complaints about the amount of transmitter time RUDAK was taking; DB2OS commented:
The test code which Assi is working on is only a small part of things to come. This is to get a feeling about the I/Q modulator and performance of the DSP modems. And indeed it s a good test for you and other to test the system sensitivity, similar to the ZRO test in the good old days. The idea is to use the DSP modems for 1200 Bit/s BPSK PACSAT type operations, which would allow us to run RUDAK in parallel with the transponder passband.
Whatever will allow them to run the Passband and RUDAK downlink in parallel should be fine. 9600bps FM causes problems with distortion when the passband is on. 1200 Bit/s BPSK should be easy and if it works, they can look further ahead to other simultaneous digital modes.
Se ven ANS 202.
Klla: ANS 202, AMSAT-UK