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Gathering the Building Blocks -- You can build a Homebrew SDR (even Manhattan Style)

As the smoke clears with all the administrivia of the past month finally reaching an end state, I am looking to build another SDR SSB Transceiver. Only this time using a minimalist approach, and thus, the blog now becomes my documentation of progress (and failures). As I was lucky enough to build a 7 transistor SSB transceiver I proceed with great hope, and a bit of caution, to create something as simple only using SDR techniques.

So, this posting is maybe a "heads up" for those who are uninterested in such a project and now is a good time to seek out other blogs.

My process will be no different than what I regularly use and that is a modular approach. As a starter do not get your underwear in a twisted knot -- this project relies on integrated circuits, surface mount components, Arduino code, USB sound cards, a Raspberry Pi Pico and Raspberry Pi 5 SBC. Last but not least the venerable Si5351.

For those already feeling queasy at the mention of Surface Mount Devices (like ADE-1's) you have a solution as Todd, K7TFC sells mounted ADE-1's that can be integrated into Manhattan style construction.

In a nutshell, the topology will use the Raspberry Pi5 as the computer to house the software (QUISK) with the Pi Pico handling the interface to the SDR hardware, frequency generation ala Si5351 and T/R control of the main board. 

The mainboard contains two DCR's (ADE-1's), two Modem transformers, a splitter to create two RF streams on receive and one composite signal on transmit, a couple of relays, Band Pass Filter and steerable amp (BFR106). A mounted BFR106 also available from K7TFC, serves as the Rx receive amp and Tx pre-driver.

Following this lash up we need a Transmit Driver Stage and a Final RF Amp (RD16HHF1). A USB sound card (Optimal Shop now with tariffs ~ $2o) and a headset/mic with inline USB sound dongle for the mic input and sound output.

The very 1st module to acquire and most expensive is to lay your hands on a Raspberry Pi5.



You will also need the fan/heatsink combo, SD card and a 5.1V / 5Amp power supply. Figure $100 for all. But you are buying a fairly sophisticated computer that is 64 Bit and good enough for Netflix streaming. So, while not in use with the SDR it can be a shack computer.

Listing of Modules

R Pi5 with Fan/Heatsink and Power Supply
R Pi Pico with Si5351
USB Sound Card
USB Headset Microphone
Transmit Driver
Transmit Final (RD16HHF1)
Main Board~ADE-1's, Relays, 2 Xmfrs, etc
Linear Amplifier Switch Box
Misc: Monitor, keyboard and mouse, QUISK

Our next blog post (separate posts) will be a block diagram and more hardware acquisition details.

Time to bail if this seems boring to you. But today's conspiracy theory is that the price of eggs has to do with Bird Flu coming from you know that foreign place offshore. But that begs the question who are the largest egg suppliers to the USA and who is getting rich with a $15/dozen carton of eggs? 

Them that know can make it go.

73's
Pete N6QW

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