Marcus D. Leech
On 06/09/2019 01:55 PM, David Eckhardt wrote:
I'm very confused by your bandwidth comments here. I don't know much about SDR#, but if it shows a couple of MHz around the notional
line frequency of 1420.40575MHz, and allows deep integration, then you've covered essentially ALL of the hydrogen line doppler range within
The next reasonable "target" for an amateur setup is the emissions from our sister galaxy, Andromeda, which are up-shifted to around 1422.5MHz
or so due to blue shift (Andromeda is hurtling towards us). Very long integration times would be required, due to having to deal with
inter-galactic, rather than inter-stellar, distances.
Here at CCERA, we operate a 21cm spectrometer, using AirSpy receivers on a 1.8m dish. Our final bandwidth is about 2MHz, which allows us
to "see" features at +/- 170km/sec from the rest frequency. Our software is Gnu Radio based, rather than based on AstroSpy or SDR#.
I'll likely do a write-up sometime soon.