Hi Dan One of the tradeoff studies the guys are doing is the cost of a 48 channel analogue downconverter and low sample rate ADC. At present, direct demod with a SNAP looks simpler in terms of hardware complexity, but has not been costed.
One of the team has actually implemented all the digital backend (including RFI excision) on a GPU, so in principle, all we need are time stamped packets of samples, and nothing on the FPGA, except demod, decimation. Thanks for the ideas coming in to the team. Regards On Fri, 25 May 2018 at 18:59, Dan Werthimer <d...@ssl.berkeley.edu> wrote: > > > if vinand, > > if you want to digitize 48 signals with 250 KHz bandwidth, you might want > to consider > purchasing a 48 input PCIe ADC board and doing the signal processing in a > computer (in software). > (not use FPGA boards). > but then you'd have to mix the deuterium line to baseband, so you'd need > 48 downconverters. > > if you want to use snaps, and you don't have much processing to do on the > fpga, and you want to save money, you could > plug in a ADC16 board into the snap - > this is a bit of a cludge, but would give you 28 channels per snap (16 > external ADC channels, and 12 on board ADC channels). > > if you have a roach1 or roach2 lying around, there's a 64 channel adc > board you could use that sample at up to 50 Msps; > i'm not sure about the analog bandwidth - you might not have to use > downconverters... > > best wishes, > > dan > > > > > On Fri, May 25, 2018 at 6:24 AM, Vinand Prayag <vinan...@gmail.com> wrote: > >> Hi, >> >> Please find attached the User Requirement. The bandwidth is actually only >> 250KHz >> >> Cheers, >> Vinand >> >> On Fri, May 25, 2018 at 5:20 PM Marcus D. Leech <mle...@ripnet.com> >> wrote: >> >>> On 05/25/2018 07:28 AM, Vinand Prayag wrote: >>> >>> Hi all, >>> >>> We are looking at building a telescope in Mauritius which is called the >>> Mauritius Deuterium Telescope, MDT for short. As the name suggests it is a >>> Deuterium focused experiment. We have planned for a pathfinder station to >>> be built for the end of this year and had in mind the SNAP boards for the >>> digital back-end. We were set to buy four SNAPs by the end of next month >>> but a sudden slash in funding has put a dent in our plans. I was wondering >>> if anyone has any unused SNAPs that we can get off their hands at a reduced >>> price. Currently one SNAP is sitting at $3500 from Digicom. Anything below >>> $3000 will greatly help us. We will obviously be extremely grateful for >>> donations. Hope to have some positive feedback from some of you. >>> >>> >>> Kind Regards, >>> Vinand Prayag >>> >>> Do you have a pointer to a project description? >>> >>> Why such high bandwidth if you're looking at Deuterium? >>> >>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "casper@lists.berkeley.edu" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to casper+unsubscr...@lists.berkeley.edu. >>> To post to this group, send email to casper@lists.berkeley.edu. >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "casper@lists.berkeley.edu" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to casper+unsubscr...@lists.berkeley.edu. >> To post to this group, send email to casper@lists.berkeley.edu. >> > > -- > You received this message because you are subscribed to the Google Groups " > casper@lists.berkeley.edu" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to casper+unsubscr...@lists.berkeley.edu. > To post to this group, send email to casper@lists.berkeley.edu. > -- Michael Inggs 10 Devon Street, Simon's Town, South Africa. Tel: +27 21 786 1723 Fax: +27 21 786 1151 Skype: mikings Cell: +27 83 776 7304 "Ex Africa semper aliquid novi" -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu. To post to this group, send email to casper@lists.berkeley.edu.
