On Mon, Jul 20, 2020 at 02:31 PM, M0ZHN wrote:

Seems to be a better choice for an LO than the Si4432

Seems to be a much better choice for the screen size too!!!
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John P.
WA2FZW

Good evening,

Not wanting to digress from the current design, I have stumbled across this:



It is somewhat similar to the tinySA but uses LM61E2 as the LO. Seems to be a better choice for an LO than the Si4432. Perhaps will try and see if I can give it a go.

Just sharing my thoughts...

73 Elia, M0ZHN

Erik,

I'm certainly interested in knowing the vendor and price for this TinySA - keep us advised.

73 de Marty, KN0CK

Cheers Glenn, that was quick :D

Elia
M0ZHN

开云体育

开云体育

Hi,

Trying to look at the latest schematics for the tinySA but the links on Glenn's site seem to be broken. Anyone has a copy and willing to email them please?

73 Elia, M0ZHN

Hi Dave,

Thank you for the offer of a trial firmware. I would like try the first option of using an additional SI4432 and ADE25 with the SI4432 CS coming from the ESP32. When this works well will aim to add an attenuator/amplifier as suggested by Erik.

I can put the additional components on a PCB that mounts onto the tinySA sandwich so the SPI lines will be kept short.

By the way, I added shielding to my unit, the overall noise slightly reduced but the spike near 70MHz is still there.

73 Elia,
M0ZHN

What a nice piece of work!!
Reaching this stadium of completeness, I presume it will be available soon.
Can you give us any clue about the approximate starting date, price and vendor(s)

Groet ,
Fred, PE1PAB

I like Bill's proposal of a second SI4432 in the tracking generator, probably easier to get a flat response and good isolation than adding an attenuator/amplifier.? Of course then its almost another TinySA.

Assuming this will go with your homebrew ESP32 TinySA then there are some options to experiment with:

• Try your proposal and see how well it works.? Perhaps use a passive splitter/combiner (2 off 33R in parallel for each branch should be near enough) and fit a dummy load to the port when not in use. Requires one SI4432, mixer and assign an IO pin to select it.? With a suitable pull up on the tracking generator and pull down on the main board it should be simple to detect if the tracking generator is connected on power up and initialise it to output the correct frequency.? Tracking generator will need to be positioned close to the TinySA to keep the SPI bus short.? This is easy to do.? Another option would be to use an Arduino Nano, ESP32 or similar that just sets the SI4432 frequency on power up.? This is also easy to do but slightly more work.? Gives more flexibility in locating the tracking generator somewhere convenient on the bench.
• As above with attenuator/amplifier as Erik suggests
• Add another SI4432 to the tracking generator as Bill suggests.? Needs another IO pin assigning.? The TinySA code will then have to control the tracking generator LO as the sweep progresses.? This is also easy to do.
• Make the tracking generator completely independent with its own ESP32 and power source, synchronised to the main sweep via the ESP32 Wifi.? Allows the tracking generator to be positioned anywhere convenient, but a LOT more work to implement so if anyone needs that then its DIY.

If you want to try any of the easy ones let me know and I can create a version for you to try out.? Pins 32/33 (reserved for encoder but unlikely to be implemented) or perhaps better 16/17 should be available for use.
If it works out OK then would need to add ability to calibrate frequencies of the other SI4432 to the menus.

Dave M0WID

Very nice indeed.? The telescopic whip is an interesting touch!? and I think should increase the number of potential purchasers.? A SMA-BNC adaptor or cable would also add value.

If the price is right you have a customer (I paid ?36 delivered for my Nano-VNA, which i think is a genuine one, though its hard to be certain).

Please let this group know when they become available and where to purchase.? Its sure to be a great success.

73
Dave M0WID

I don’t think you need a more detailed description of what others have written.
Read back links here: /g/HBTE/message/1023
Successful installation and programming.
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Gyula HA3HZ

Beautifully done Erik.
??? This is the standard of finish to a project that I aim for, and only occasionally reach.
Tony Jaques

Hi, I have a blue pill board and can't load a program that communicates with the PC TinySA.exe. Could someone write a brief description here how to do it? Thank you in advance.

Very nice Erik! ?Depending on the price, I think this will be a very successful product!

73,

Robert, WA2T?

Very nice?

My homebrew project is nearing completion

Two pictures for those interested





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

At the time i designed the tinySA board (V1 in March) I did not have the Attenuator module in my possession, so it was done using pictures as a "guide". I only got the Atten a week or so ago and it is one of the reasons I updated to a V2 version. (still in progress)
To get around the problem of the pads & components on the bottom of the Atten board, the cutout was included on the tinySA V1 board. And easiest way to make it usable was to fit some spacers under the Atten board.? For the 3v3 supply, the hole between C19 & C33 can be used, with a wire over the top of the Atten.

If you find a way to not use washers, go ahead. You might want to put a piece of heat resistant tape under it though where it might short out.. eg Kapton tape.

Glenn


Hi Robert,