SDR School Part Two the Hardware
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- čas přidán 15. 07. 2024
- SDR School Part One discussed basic SDR principles. Here in Part Two, I talk about SDR hardware. Part Three will show how software puts it all together, but that's not done yet. SDR School is designed to show SDR principles in a non-technical fashion.
Thank you, Dave.
Its simply perfect for teaching SDR basics and principle to my radio club! Great job David! 73
Hi Dave! Another great presentation with both excellent commentary and graphics. I always keep a pad and pencil handy when I watch. Looking forward to Part 3!
Good stuff, dave! We have a new ham in DELARA who asked me about SDR. I gave him my simplistic explanation and then promptly pointed him to your videos. I eagerly await Part Three.
Perfect! Very clear and good explanatition. Just what i needed as i was looking to purchase an SDR. In my list is also a SDRplay RSPduo Dual Tuner 1kHz-2000Mhz Wideband SDR Receiver. Looking foreward to part 3. Thank you for all the effort, time ......
73's Wouter on3fox
i do enjoy listening to you, watching your video's, and you sharing the things you have done
Thank You. Very nice. I'm beginning to understand now
keep these videos coming Dave.. great job
Interesting video and appreciate this was made at the beginning of the year and things in this arena are moving quickly. Was hoping you would cover some of the more budget end and popular sdr receivers with comparisons between them, such as the various rtl-sdr, Nooelec Smartee series along with their HamItUp , HackRF etc.
Wonderful series. Now I have to find out how to decode RTTY. I saved about 15 minutes of the RTTY contest last night since they pretty much overran 40m. I figure I can use that to learn the RTTY setup after the fact. I am pretty used to working RTTY with my KX2 and KX3 and a paddle.
ANOTHER EXCELLENT video ! tnx 4 the upload !
73 N8AUM
Thanks 4 sharing :-)
Very, very well done series and several of my ham friends and I look forward to the next video in the series. I particularly liked the folding waveform when you were explaning phasing and I/Q. Would you share how you did that and also your recording setup? I hope your next video talks about recording the entire spectrum.
Thanks for the compliment! The folding waveform was not easy. I captured two screens (with Movavi), one with the waveform, and one without (by disconnecting the antenna). I then masked off everything but the left half of the spectrum, and overlayed the view without the waveform over the view with the waveform. This then became my background (waveform on the right - no waveform on the left). I then used the same mask to to create a key of the waveform on the left. I then used a flip effect to flip it from side to side. Whew!
Dave W8KFJ
Wait, we learned all that? I gotta go back and watch that another 20 or so times I guess.
Great videos Dave. I take it after watching these that you still like the Elad SDRDuo? I purchased a SDRplay and really like it and if the Elad is better I think I will eventually get one. Can't wait for part 3, thanks for taking the time to make these great videos.
As I do more tests for part three, I am reminded of the superiority of direct sampling. SDRplay is not in the same league as the other radios I have. Dave W8KFJ
Thanks for complimenting my videos. All the other radios (all direct-sampling) are a big step up from SDRplay. The DUO is still at the top of my list, but others have a lot to offer as well. Dave W8KFJ
Very informative and I, too, am looking forward to Part 3. I am however, curious as to what you suggest for the antenna, especially operating QRP?
I normally run about 500 watts with the ALS600. Dave
Another great video. Very interested changing Amp to provide near full output with low drive as I'm running a 50w amp atm and was looking at SPE 1k or 1.3k as low drive still gives 400/500w but very expensive option. Please email direct if you wish to provide info, email good on QRZ.
cheers Adam VK2YK
The 'List of software-defined radios' wiki doesn't have a column for 'direct sampling'. How do you know if an sdr supports it? Specifically, the LimeSDR, or even the HackRF?
And if it doesn't support it, is it possible to add via a hardware hack? For example, I've seen you can avoid the up-converter on an RTL-SDR by soldering an antenna on the RF IC (RTL2832 Pin1).. the software (SDR#) can then be configured for Direct Sampling (I branch or Q branch)
www.rtl-sdr.com/new-experimental-r820t-rtl-sdr-driver-tunes-13-mhz-lower/.
Ben - My first answer was going to be that you can't modify a direct conversion receiver to direct-sampling. I did take a look at your link, and I see what they're doing. If a receiver down-converts to a base spectrum of, say 10 MHz, then you could bypass the down-converter, and then tune possibly up to 10 MHz. By tapping the signal at either the I or Q branch, this "direct-sampled" signal is then used to digitally create the I and Q signals - with the special mode in the software. This will work for fairly low frequencies, but sure takes a lot of work - and you still don't have a very good receiver. To direct-sample some higher frequencies, you're still going to need the proper anti-aliasing filters, a pretty fast A/D, and an FPGA to handle all that data - probably beyond the scope of field mods. You're learning more about SDRs though, and teaching me a little at the same time.
Dave W8KFJ
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