tag:blogger.com,1999:blog-4774014561040227748.post5948803607966153462..comments2024-03-22T10:42:05.161-06:00Comments on KA7OEI's blog: Comparing the "KiwiSDR" and the "RaspberrySDR" software-defined receiversUnknownnoreply@blogger.comBlogger16125tag:blogger.com,1999:blog-4774014561040227748.post-44678919939244829792020-10-07T10:23:20.100-06:002020-10-07T10:23:20.100-06:00The changes to the Verilog code are in a the fpga_...The changes to the Verilog code are in a the fpga_64bit git branch in the same repository. - AB1KWRik van Rielhttps://www.blogger.com/profile/10005713043841888341noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-57697649845673512132020-10-05T18:36:25.897-06:002020-10-05T18:36:25.897-06:00ADC Ref voltage on RaspSDR of LTC2208 is
1.5V no...ADC Ref voltage on RaspSDR of LTC2208 is <br /> 1.5V now and can be change to 2.25V by remove a resisitorfei666888https://www.blogger.com/profile/09955670982661491697noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-40127168128283180042020-10-03T16:51:28.998-06:002020-10-03T16:51:28.998-06:00Because the code is inherited from the KiwiSDR, It...Because the code is inherited from the KiwiSDR, It is capable of the same numbers of users, as in:<br /><br />3 users - 20 kHz bandwidth, full waterfall<br />4 users - 10 kHz bandwidth, full waterfall<br />8 users - 10 kHz bandwidth, 2 full waterfall channels, 6 audio-based waterfalls<br />14 users - 10 kHz bandwidth - no full waterfall channels, 14 audio-based waterfalls.<br /><br />I believe that most of the limitation has to do with the FPGA capabilities rather than the amount of processing power. Because the Raspberry Pi is can be more capable, it may be that more users can use software-intensive extensions - such as Digital Radio Mondial (DRM).<br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-48574712461921351412020-10-03T16:13:00.771-06:002020-10-03T16:13:00.771-06:00How many users are possible on kiwi (4?) and on Ra...How many users are possible on kiwi (4?) and on RaspberrySDR (???)DG1KPChttps://www.blogger.com/profile/02422229965719979124noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-18581738042463539382020-10-01T19:16:07.638-06:002020-10-01T19:16:07.638-06:00The RaspberrySDR and KiwiSDR have pretty much iden...The RaspberrySDR and KiwiSDR have pretty much identical latency because they share a common legacy. Not counting network latency, it is a bit under 1 second.<br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-19089589919699840152020-10-01T11:42:09.768-06:002020-10-01T11:42:09.768-06:00The audio output on the KiwiSDR is delayed about 5...The audio output on the KiwiSDR is delayed about 5 seconds as opposed to very little delay with webSDR. <br /><br />What latency in received audio can be expected from the RaspberrySDR?Richardhttps://www.blogger.com/profile/11321508585133236325noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-25093883810723436122020-09-22T17:35:56.173-06:002020-09-22T17:35:56.173-06:00Perhaps a bit of "Google-fu" is required...Perhaps a bit of "Google-fu" is required, but one possible search phrase for EvilBay and AliBaba is this: "New 16bit 62M real-time bandwidth network shared SDR receiver".<br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-91218489104438668082020-09-22T13:17:48.264-06:002020-09-22T13:17:48.264-06:00I was looking around and cloud not find a place to...I was looking around and cloud not find a place to buy the RaspberrySDR. Does anyone knows where it can be bought from?blog userhttps://www.blogger.com/profile/18389091468702144209noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-24978251505460109882020-09-20T14:59:52.184-06:002020-09-20T14:59:52.184-06:00Thanks - updated.Thanks - updated.KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-5948403370008676232020-09-20T14:35:14.337-06:002020-09-20T14:35:14.337-06:00It seems that the FlyDog GitHub link you posted in...It seems that the FlyDog GitHub link you posted in your article is now dead. Searching GitHub I came up with the another FlyDog link which most likely represent the code for the board you've tested as the layout looks identical, but the logo has changed:<br /><br />https://github.com/mfkiwl/FlyDog_SDR_GPS<br /><br />Thanks for your insightful article and comparisons.<br /><br />73<br /><br />andyz - K1RA<br />AndyZ - K1RAhttps://www.blogger.com/profile/05062907666638857018noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-73319323108660427912020-09-20T14:14:37.435-06:002020-09-20T14:14:37.435-06:00In theory, doubling the sample rate should result ...In theory, doubling the sample rate should result in an ENOB (effective number of bits) increase of 0.5 - which would be on the order of 3dB benefit.<br /><br />As for the preamp and matching network, I didn't feel like removing the soldered-on shield covers to inspect what are likely a number of unmarked components - although the simplicity would make signal flow analysis pretty easy. Based on the response curve of the Nyquist filtering I would presume that it's of the same topology as the KiwiSDR - the inductors and capacitors simply rescaled for the new frequency.<br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-7295704027737501112020-09-19T01:09:57.408-06:002020-09-19T01:09:57.408-06:00Clint
Thank you for a very useful analysis and tho...Clint<br />Thank you for a very useful analysis and thoughtful comments. I wonder if you could comment on two aspects that I can't see in your post:<br /><br /><br />1. Processing gain from the higher clock speed in the RaspberrySDR - should there not be a benefit?<br />2. Does it use the same preamp chip and matching networks at input and output as in the KiwiSDR, as these affect the performance metrics you've covered.<br /><br />73<br />Gwyn G3ZIL<br />Gwyn Griffithshttps://www.blogger.com/profile/10465327891156197862noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-59917260617925698762020-09-17T19:19:23.725-06:002020-09-17T19:19:23.725-06:00Thanks for looking into it.
In the spirit of open...Thanks for looking into it.<br /><br />In the spirit of open source, a public git repo would be very nice!KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-56538470852280653522020-09-17T19:18:33.236-06:002020-09-17T19:18:33.236-06:00Good questions - no answers as of yet.Good questions - no answers as of yet.KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-83777802671470431362020-09-17T17:44:49.929-06:002020-09-17T17:44:49.929-06:00But where are the GPL sources of the (hopefully) m...But where are the GPL sources of the (hopefully) modified Verilog code for the FPGA that actually make use of the extra two bits from the ADC?<br /><br />All that repo has are the RaspSDR.*.bit binary files (in addition to the KiwiSDR.*.bit files)<br />jkshttps://www.blogger.com/profile/07329067447359706748noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-91142847397113538992020-09-17T04:18:04.834-06:002020-09-17T04:18:04.834-06:00The source code for RaspberrySDR is here:
https://...The source code for RaspberrySDR is here:<br />https://github.com/raspsdr/Beagle_SDR_GPS<br /><br />You made good points on S-Meter caculation. I believe there is bug in the code. I will take a look to see if I can fix it.<br /><br />Also, there is a group here to discuss:<br />https://groups.io/g/raspsdrHowardhttps://www.blogger.com/profile/11745966488763447211noreply@blogger.com