Show us your build !

[penfold42]

No matter how modern, steampunked or deviated from the recommended design :)

I'll kick things off... Mine has a few substitutions based on what was to hand: TL072 for the opamp 74HC4052 scavenged from a Pace set top box :) The four tayloe caps are 27nF cos the 74HC4052 has a higher Ron Small proto area that I can use for band low pass filters (the green wire. This board runs at 5v so there's a pair of 1.8k/3.3k resistors to drop the amp outputs to 3.3v max No preamp.

Its good for about 10MHz, FT8 on 14MHz is buried in noise. Local AM stations are fine on an old skool wire loop antenna and some will totally overload the radio when on my EFHW. The EFHW works well for 40m stuff.

Top view with SH1106 and buttons - the 2 boards could be folded back to back

Close up of the RF front end board

And some pretty average soldering...

[dawsonjon]

Brilliant 👍 I love this stuff 😁

[mryndzionek]

My first build was similar, but I fried some components while experimenting with random wire antenna and grounding. The second one is a little bit tidier :smile:

[penfold42]

My first build was similar, but I fried some components while experimenting with random wire antenna and grounding. The second one is a little bit tidier 😄

pictures or yours doesn't exist...

you dissen my neatness bro?? When I get around to ordering, ill probably just replace the RF board with the 3253 and an smd 6022 both on the green breakout. At least it'll be mostly 2 dimensional

[mryndzionek]

This is my current build. I run out of toner transfer paper, so had to draw it using a sharpie :face_exhaling:

[dawsonjon]

Nice! Love the hand etched PCB 👍

[MrSVCD]

My first build. It's needs 5v for the analog switch chip and I have had bad luck with power banks giving noisy output so I went with 6 ni-mh and a LDO linear regulator. The next one is going to be a experiment in Manhattan PCB design.

[dawsonjon]

Very neat!

[bahari]

This is my projects setup. I'm adding RX amplifier, programmable step attenuator, low pass filter and LM386 speaker amplifier hardware. I'm also editing the existing code to include a menu for programmable step attenuator.

[dawsonjon]

Very cool, really like the step attenuator. How are you controlling it?

[JimReagans]

This is my2nd build of Jon's picoRX. I'm using a pico2 with an external Tayloe decoder which allows me to mess with filter parameters. Cheers, Jim W0CHL

[dawsonjon]

Nice work!

[bahari]

Very cool, really like the step attenuator. How are you controlling it?

Basically the relay controlling 3 attenuator base value which is 3, 5, and 10dB. From the combinations of this 3 value I can get an extra 10, 13 and 18dB. I'm adding 3 GPIO from Pico to control the relay via ULN2803. I modified your code with extra attenuator menu to select which attenuator value to used. This really help when I'm attaching my 20dB RX amplifier for strong signal attenuation process.

[penfold42]

Very cool, really like the step attenuator. How are you controlling it?

Basically the relay controlling 3 attenuator base value which is 3, 5, and 10dB. From the combinations of this 3 value I can get an extra 10, 13 and 18dB. I'm adding 3 GPIO from Pico to control the relay via ULN2803. I modified your code with extra attenuator menu to select which attenuator value to used. This really help when I'm attaching my 20dB RX amplifier for strong signal attenuation process.

Nicely done! Are you able to share your code? Adding support for a PE4302 attenuator is on my list and it would be good to support multiple attenuator approaches. I'll probably start with using 3 GPIOs to control the high order bits but move to I2C via a PCF8574

[bahari]

Attached are the code. Effected code are ui.h, ui.cpp, rx.h and rx.cpp. Yeah using i2c is the right choice to control it. code-atten-cntrl.zip

[penfold42]

Attached are the code. Effected code are ui.h, ui.cpp, rx.h and rx.cpp. Yeah using i2c is the right choice to control it. code-atten-cntrl.zip

Thanks! I got a shock when i diffed it against my working tree. Then realised your code is based on master, not the testing branch where heaps of work has been happening lately! :)

[bahari]

Attached are the code. Effected code are ui.h, ui.cpp, rx.h and rx.cpp. Yeah using i2c is the right choice to control it. code-atten-cntrl.zip

Thanks! I got a shock when i diffed it against my working tree. Then realised your code is based on master, not the testing branch where heaps of work has been happening lately! :)

Is there is any major update that improve the receiver performance on the testing branch?

[MrSVCD]

Basically the relay controlling 3 attenuator base value which is 3, 5, and 10dB. From the combinations of this 3 value I can get an extra 10, 13 and 18dB. I'm adding 3 GPIO from Pico to control the relay via ULN2803. I modified your code with extra attenuator menu to select which attenuator value to used. This really help when I'm attaching my 20dB RX amplifier for strong signal attenuation process.

How does one build a attenuator? I don't really have any strong signals nearby but I am going on a vacation to a place should have stronger signals.

[penfold42]

Basically the relay controlling 3 attenuator base value which is 3, 5, and 10dB. From the combinations of this 3 value I can get an extra 10, 13 and 18dB. I'm adding 3 GPIO from Pico to control the relay via ULN2803. I modified your code with extra attenuator menu to select which attenuator value to used. This really help when I'm attaching my 20dB RX amplifier for strong signal attenuation process.

How does one build a attenuator? I don't really have any strong signals nearby but I am going on a vacation to a place should have stronger signals.

It can be as simple as 3 carefully chosen resistor values as described here. In @bahari design this is built on a relay that can switch them in or bypass them. Then repeat this 2 more times with different values for different levels of attenuation.

You could just pre-build some plug in modules of fixed attenuation and manually plug them in

[bahari]

Basically the relay controlling 3 attenuator base value which is 3, 5, and 10dB. From the combinations of this 3 value I can get an extra 10, 13 and 18dB. I'm adding 3 GPIO from Pico to control the relay via ULN2803. I modified your code with extra attenuator menu to select which attenuator value to used. This really help when I'm attaching my 20dB RX amplifier for strong signal attenuation process.

How does one build a attenuator? I don't really have any strong signals nearby but I am going on a vacation to a place should have stronger signals.

It can be as simple as 3 carefully chosen resistor values as described here. In @bahari design this is built on a relay that can switch them in or bypass them. Then repeat this 2 more times with different values for different levels of attenuation.

You could just pre-build some plug in modules of fixed attenuation and manually plug them in

It is based on PI attenuator topology. To calculate it based on your need, please go to this calculator link: https://leleivre.com/rf_pipad.html

[penfold42]

Finally got around to ordering better parts and built a new analog board. 74CBTLV3253 and MCP6022 as originally spec'd but I was powering the old board with 5V so theres a 1117-3v3 regulator on the board

I forgot how fun SMD donut board work is:

I've got enough room for an LNA but might need a 3rd board for band filters.

Performance is somewhat better based on a simple reported signal level using a TinySA as a signal generator.

Let me know if anyone wants me to do a comparison test of anything else before I recycle the old board...

[MrSVCD]

Have you tried to battery powering your board? I have noticed that USB power is quite noisy. Might just affect my build since I use a 5v powered switch.

[penfold42]

Have you tried to battery powering your board? I have noticed that USB power is quite noisy. Might just affect my build since I use a 5v powered switch.

Yep - no perceptible difference from my laptop. What is crap tho is a marketing event power bank - very noise switching in it.

[mryndzionek]

What is crap tho is a marketing event power bank - very noise switching in it.

Curious, I actually built-in a power-bank module into mine and I almost don't see a difference. I believe it's 134N3P-based.

[MrSVCD]

What is crap tho is a marketing event power bank - very noise switching in it.

Curious, I actually built-in a power-bank module into mine and I almost don't see a difference. I believe it's 134N3P-based.

Where do you take your power from? directly from the battery or from the 5V?

This module, Lipo Amigo Pro, should not produce any noise https://shop.pimoroni.com/products/lipo-amigo?variant=39779302539347 since it is taking the power from the battery almost directly, only going thru an battery protection circuit.

[MrSVCD]

I could not help my self, so I built a second one. This is my first Manhattan build.

Since I like woodworking I am also building a bookshelf shell for it with built in speaker. The shell is not ready for showing of just yet.

[MrSVCD]

As part of my build I made a minimal Pico Holder https://github.com/MrSVCD/PicoRX-accessories/tree/main/PicoHolder

[MrSVCD]

So I am going traveling in a week and I can'd do that without a PicoRX. This is my handheld 3D printed version: Operating.webm The only thing lacking in this build is USB, I have some ideas on repurposing plugged up button spot. Ps.The metal box is the power supply to my active antenna.

[indrasung]

Finally done.

[dawsonjon]

Looks great 👍

[MrSVCD]

Very clean, very demure as the kids say (or said).

[ericeness]

Ever since I saw a writeup of this project in Hack-a-day, I have wanted to try it out. So far I have built two versions and both work to a certain degree. Each build has been a learning experience. I am already thinking of V0.3.

V.01 was built on a breadboard. I was so eager to try it out that I got sloppy towards the end. Once I figured out I forgot the connect the 3.3v from the Pico to the plus rail. It worked! All I could hear were some AM stations but, the crystal radio has been reinvented.

V0.2 was soldered down on a protoboard. I decided to copy Jon's layout as best I could from the various pictures I could find. I tried to build a nice little control panel but the display didn't work. I put a new display on a solderless breadboard and yet another Frankenstein monster was born. This version can receive some shortwave broadcasts but, some of the stations, even with a good signal strength, cannot be received.

I happen to have an AirSpy HF SDR running across the room. I use the AirSpy to spot stations to try out on the PicoRx. I saw that the WWV time station on 15 MHz was coming in good and so I tried it on the PicoRx. I could not hear WWV on the PicoRx at all. Looking over at the AirSpy, I see three strong signals from the Pi Pico. Clearly these signals are the local oscillator and perhaps sub-harmonics? I now regret tucking the wires carrying the LO signals under the Pi Pico to reduce the number of flying wires. For V0.3 I think I will use twisted pairs to carry the LO and Sampled signals.

[indrasung]

Hello Ericeness, good works. Looking forward hearing from you about using twisted cable from pi pico pin 1 and 2. How about using shielded coaxial rg174.

[JimReagans]

My pico-rx build is taking shape! I need to cut down the length of the case yet. Your mileage may vary, Jim W0CHL

[MrSVCD]

@JimReagans how did you get the colour spectrum waterfall?

[JimReagans]

MrSVCD: The software is available under the TFT branch. I believe Jon will be publicly updating with a video and software by this next weekend. Once you have the software, you go into the "HW config" menu and it will allow you to add the second screen (ILI9341) and set up colors & displays. Cheers, Jim

On Wed, Nov 20, 2024 at 8:31 AM MrSVCD @.***> wrote:

@JimReagans https://github.com/JimReagans how did you get the colour spectrum waterfall?

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