Avoid the pins on the nano that double as uart pins
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HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Erik,

I have the 'Blue Pill' and the Nano (I bought both) but plan on using the Nano for my first build. Is the Nano what you're using, or what Arduino did you use for your build and was there any level-shifting??

73 de Marty, KN0CK

If you use an Arduino with actual serial interface you may have to choose other pins
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HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Daniel.

From what I read of Erik's Build Instructions, here's what connects to the Arduino (Nano or otherwise - not sure about the 'Blue Pill' version):

Pin? ? Note
6? ? ? ?SDO Connect to D3 of the Arduino (WARNING: You MUST use a 3.3V compatible Arduino)
7? ? ? ?SDI Connect to D2 of the Arduino (WARNING: You MUST use a 3.3V compatible Arduino)
8? ? ? ?SCLK Connect to D1 of the Arduino (WARNING: You MUST use a 3.3V compatible Arduino)
9? ? ? ?nSEL Connect the RX module to D0 and the LO module to D5 of the Arduino (WARNING: You MUST use a 3.3V compatible Arduino)

Hope this supplemental information helps.

73 de Marty, KN0CK

May I suggest you change the footprint for the impedance matching around AND between the SAW filters to CLC Pi configuration?
Impedance matching between the two SAW filters can give significant improvement. There you need a footprint for CLCLC
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HBTE Files section:?/g/HBTE/files
Erik, PD0EK

????? I have attached my version of the schematic diagram . To get to the PCB stage I have to have the correct connections with the controller. Is anyone kind enough to tell me which pins connect LO and RX to HW-267 (STM32F103C8T6 STM32 Development Boards (Blue Pill)?
I want to clarify the following about my schematic :
RLC values are generic.
System ground does not reflect the appropriate situation in the future PCB. It's just the electrical connections. For example, on the SAW ?Epcos ?B3555 filter the ground connections for the housing are top and the signal ground connections must be to the bottom PCB plane?to avoid the "ground-loop"?.
Level Shifter is optional.
I have no connection to the attenuator because I don't know what data pins are connected at STM board.

Any suggestions on removing / adding components or changing the controller are welcome.

Daniel? Ungureanu

YO8SAK

开云体育

Ahh ha! ?Yes I am using a temporary sub-standard one SAW filter.

Looks like the image created inside the SI4432 due to insufficient selectivity of the SAW BPF.
What SAW filters are you using?
I did a post some time ago on this issue
--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the [email protected] group.

• /VA3NOI/Eagle/Mixer_Design_Files.zip

Uploaded By: Ion Petroianu, VA3NOI <ion.petroianu@...>

Description:
ADE-25MH mixer board. schematic, PCB, Gerbers for 12 pcs panel

Cheers,
The Groups.io Team

You guys are a lot smarter than me, but,
I have been seeing something that I can't understand, but maybe this is the AGC action that Dave is seeing.
When looking at my AD9851 (DDS-60 kit) I always have a funny? response on the low frequency side only.
My 9851 is generating SSB?? It is always on the low side and it tracks with frequency changes.? Any ideas?
Gary
WB6OGD

Erik / Karl,

Thanks VERY MUCH for the link and latest info - - I hope to have my TinySA running when I get all the parts in hand tomorrow. Right now I have the transceiver boards, the mixer, and the 9431 display, but the rest of it shows up tomorrow. I am going to try the 3.3VDC mod to the Arduino Nano for my controller, but I also have the 'Blue Pill' as my backup.

More as I have it and many thanks again for the link, Erik - you've created an avalanche of interest with this TinySA..!

73 de Marty, KN0CK

It's here:?

Search GitHub for tinySA
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HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Interesting indeed.

Some more pictures.??

First with x69 = 60, agc enabled



And with the gain fixed:



Perhaps some explanation - the response of? my SAW filters as measured with a NanoVNA:



I tried with and without matching for the filters.? With matching (pink trace) the response is much flatter but has the feature around 438MHz.? I figured, perhaps wrongly, that the narrow response at the IF without the matching (brown trace) would be an advantage, and the other peaks far enough away to not be an issue, and no worse than having a flat passband.? My filter is on a double sided home etched PCB.? With the matching components fitted having enough vias in place proved important.

This filter response explains I think the odd agc action, but not the spurious signals present when the agc changes the gain.

Dave

Erik,

Where's the location of the Github repository so I can fetch the update? Please let me know - and THANKS VERY MUCH? - This is a great project..!

73 de Marty, KN0CK

I pushed update code to github
Rather dirty but the il9341 works, including touch so can function as a fully standalone spectrum analyzer now
--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Files uploaded to files section, folder VA3NO)I, subfolder Eagle.
Schematic, PCB and gerbers for fabrication.

73,
--
Ion
VA3NOI

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the [email protected] group.

• /VA3NOI/Eagle/SAW_Filter_QCC8C.zip

Uploaded By: Ion Petroianu, VA3NOI <ion.petroianu@...>

Description:
Schematic, PCB, Gerbers for a 10 PCBs Panel

Cheers,
The Groups.io Team

Hi Erik,

Is the .ino file for the larger display available for evaluation? I have purchased all the parts including the ILI9341 display to build my TinySA and would like to try that code on my Nano, too - I'm about 2 days from getting it built. Please advise on the newer .ino file at your soonest. This project is incredibly interesting to me.

73 de Marty, KN0CK

Interesting,

This is what I get with 0x69 set to 0x60 and a -5dBm and -30dBm signals and a 20dBm/div scale. As you can see my AGC acts much earlier.
The AGC is multiplied by 4 before display



Can you set the RBW a bit wider and see what that does?

--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK