On Monday 06 June 2005 15:28, Matt Ettus wrote: > Actually, you can do 70 MHz directly into the BasicRX. Just set > everything like you are using a 6 MHz IF (70-64=6). No need to use the > ICOM R8500 at all.
Hmm, not sure what the passband of the 70MHz filters is. Shouldn't be too much aliasing; I'll give it a whirl. > > As to the DBSRX, I mentioned to Charles Matt's statement of the 'less > > than 8dB noise figure' and Charles wasn't real impressed; need pretty > > good amplification ahead of it to get a useful noise temp. We have a few > > front ends with less than 3 dB NF here, and we will soon have better. No > > cryo here, yet. > The DBSRX is not intended to be used for RA applications without an LNA > in front of it. Besides, even if it had a 0 dB NF, you would still have > to run the coax from your feed all the way to it, which could be 10+ dB > of loss. Well, in our case we were thinking of the USRP potentially in a cabinet with an embedded PC in each feedbox (they're about 4 feet cubed). Either that or a frontend with a fiber transmitter in the feed and fiber receivers in the control room; we have 12 strand singlemode fiber run to the feeds. You need to come visit after SARA at Greenbank. :-) > The DBSRX is even has a connector for providing LNA bias over the coax. This is nice. -- Lamar Owen Director of Information Technology Pisgah Astronomical Research Institute 1 PARI Drive Rosman, NC 28772 (828)862-5554 www.pari.edu _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
