On 5 Aug 2011 at 10:28, Phil Karn wrote: Date sent: Fri, 05 Aug 2011 10:28:23 -0700 From: Phil Karn <k...@philkarn.net> Subject: [amsat-bb] Re: ARISSat-1 over West Malaysia To: "Sion Chow Q. C. (9W2QC)" <9w...@9w2qc.net> Copies to: sangatsi...@gmail.com, amsat-bb@amsat.org
> On 8/4/11 8:04 PM, Sion Chow Q. C. (9W2QC) wrote: > > > > 2. Does the CW beacon needs to be really +/- 100 Hz of the yellow > > line? The reason for this is that I would like to see how much offset > > should I apply to doppler control, for possible automated reception. > > Tuning the CW beacon to 500 Hz automatically centers the BPSK1000 signal > at 1500 Hz. I didn't put in a whole lot of frequency tolerance in the > BPSK-1000 demodulator because the signal is 2 kHz wide from null to null > and it would begin to be chopped off by the edges of the receiver's SSB > filter. So while you should ideally tune to +/- 100 Hz you might go to > +/- 200 or even 300 Hz and it will *probably* still work, but I wouldn't > go too much wider. > > Go ahead and experiment; I'd be interested in any reports on how well my > demodulator (which is incorporated into both the Windows and Mac > telemetry programs) tolerates tuning errors. Frequency acquisition and > data synchronization are the hardest parts of any digital demodulator, > and I'd like to know where there's room for improvement. > > 73, Phil > > > I try to decoded the last 30deg pass this morning but no luck even if the blue marker remain steady on the CW bump nothing "lock" as far i can tell any QRM or QRN seems to hold the lock process and on VHF here i have some intermod... living about half a mile from a cell/paget tower? "-" Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe DSTAR urcall VE2DWE WAC BASIC CW PHONE SATELLITE _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
