teesny3 general coverage DSP superhet radio

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If I get enough motivation I'll do a pair of PCBs for the radio this winter. One for the "quiet" RF/analog section, the other for the digital and large signal stuff - hosting Teensy3x, display/encoder connections, the audio adapter and likely the SCAF filters. The goal is to build a portable RX with a telescopic antenna, hence shielding the digital part is essential.
I may delay the second PCB until Teensy3++ materializes. Anyway I'll keep the Teensy related discussion here, but for the RF/analog part please follow the link.
 
Nice project! I did something along these lines - an HF SDR transceiver which uses a Softrock kit for the radio part and the Teensy for audio processing. Similar approach but the Softrock is direct conversion with I/Q in and out. My experience with the audio libraries is very similar to yours - easy to use but ultimately you may have to dive deep into the source code to do really interesting stuff. I would never have attempted such a project without them tho!

Project details, schematics and source code links on the project on my blog:

http://rheslip.blogspot.ca/2014/04/software-defined-radio-with-teensy-31.html
http://rheslip.blogspot.ca/2015/01/teesy-sdr-project-update.html
http://rheslip.blogspot.ca/2015/03/teensy-sdr-transceiver-description.html

Regards, Rich
VE3MKC
 
rheslip said:
would never have attempted such a project without them tho!
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I fully agree. The audio codec and the GUI tool steered me towards Teensy. Now that I got some feel for the Audio library structure I've written a custom module - complex input FFT for I/Q processing with the tone frequency estimator. I still need to learn how to make a GUI block for it.

You have a very nice radio also.
Speaking of which I did not have much of an 1/F noise or hum issues since the RF is upconverted and the IF stage has >20db gain. The signal at the input of the AF opamp is larger than in a classic direct conversion SDR. BTW to reduce the AGC action latency and minimize the codec / arithmetic overload probability I've hacked the AGC code directly into the codec ISR data copy routine :). The code controls the IF stage gain and works quite well.
 
BeatZero said:
Hello vladn! congratulations on the amazing project, you have plans to share the source code?
73 PP5DI
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I'd love to build one of these.
If you need an experienced constructor to test if the project is reproducible let me know.
I'm happy to have the boards made locally here in the UK from Eagle cad files or whatever!
73
G6XMO
UK
 
Wow! I felt bad obsessing over an Iambic keyer but you guys build whole radios! Put me down for PC boards. Also a suggestion, since you can sweep the DDS, use a bridge and an analog input to graph swr at the antenna jack.
 
It's been a long time, but I finally decided to make "mk2" of this radio using Si5338 synth to generate all the required frequencies. Ordered PCBs last week from OSHPark. For a very slightly outdated circuit diagram and the board outlook you can check the link below. I seriously apologize for not posting all the details here, but it is hard to maintain too parallel threads.
http://theradioboard.com/rb/viewtopic.php?f=4&t=6641&start=15

The silkscreen shows that it is a stack of several boards - the audio adapter on the RF/IF/AF SMD side, the T3.6 on the bottom, shielded by the ground plane, then the 1.3" OLED hanging over it on a separate connector.
 
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