non group buy (independent) builders

[Kazu.T]

Hi Manuel,

Thank you for this great (tr)uSDX project!

I received the (tr)uSDX PCBs (SMD parts pre-populated) from JLCPCB today, and also have received most of the parts from other venders so I will start building it today.
The order process to JLCPCB was so smooth, with your perfectly organized gerbers and BOMs, thank you so much, Manuel.

Even I have been following all the threads and topics in ucx forum for more than a year, I have never built one, so this time I don't want to miss the train therefore I ordered the PCBs right after you published the design.

Most likely I will finish my (tr)uSDX build within few days (how come PCBs arrived already but parts from LCSC that ordered at the same time??), I will need some firmware soon for testing the hardware.

Hello Guido, I am not pushing you so please take a time to finish your art. (by the way, if you need more CPU cycle during SSB TX, I have done further optimization and reduce the time in freq_calc_fast() by 15%)

So, since I am already familiar with the uSDX source code (I've ported it to STM32F072 (NanoVNA, mods to TRX) / STM32F303 (CentSDR, mods to TRX) and other ATmega based QRP kits such as QRPGuys Digital Mode Transceiver III Kit) I will start porting the uSDX open source code to (tr)uSDX hardware for testing, until Guido will release the official bootloader & firmware binaries. I believe the porting should be straightforward (just enable/disable macros) except the U1 ADC. (This porting is only for hardware testing purpose)

If someone else who wants to order (tr)uSDX PCBs to JLCPCB by yourself like me and having some questions, I may have answers (or may not!) so Manuel can focus more on supporting Group Buys coordinators.

By the way, I am NOT recommending you to order by yourself... if you have access to one of the Group Buys, you definitely should join!

Kazu. AG6NS

[DL2MAN]

Hello Kazu,

thanks for your post.
What I can see from your picture: If you want to put it in the 3D printed hausing, it will not work because your female inter pcb connector is too long. The female portion protruding over the PCB should not be longer than 3,6mm !

Your Software skills sound great ! Respect for that. I´m a hardware guy through and through. The SOftware is already available, and we will release it any day on my page.

I would actually appreciate if you would NOT release your uSDX adaption for the (tr)uSX. This would somehow sabotage our intentions here and bypass our licencse model. Please contact Guido, if you want to help. Thanks !

73 Manuel; DL2MAN

[Kazu.T]

Hi Manuel,

Thank you for your quick response and advice.

I just downloaded the bootloader hex file, wow, that is very clever way to prevent the unwanted firmware distributions by someone else.

And of course I won't publish my porting of the uSDX open source code to (tr)uSDX hardware.

OK, I need to find the similar female pin socket in US that you specified in the BOM:
https://www.reichelt.de/buchsenleiste-2 ... 66697.html
datasheet: https://cdn-reichelt.de/documents/daten ... 120972.pdf

Oh I see, you use the "shorter" side of the pin header to connect to pin socket and "longer" side for soldering. I should watched your "(tr)uSDX #2 - complete assembly Instructions" more carefully... I hope not many people will solder "shorter" side as usual, then struggle to remove & re-solder it...

For the pin header, I ordered the one specified in the BOM: LCSC:C725946
https://lcsc.com/product-detail/Pin-Hea ... 25946.html
datasheet: https://datasheet.lcsc.com/lcsc/2110111 ... 725946.pdf

According to the above datasheets, the PCB distance (surface to surface, not including the thickness of PCBs) should be 2.5mm (pin header) + 3.5mm (pin socket) = 6mm??

I'm just a programmer so always been amazed by hardware engineers, like you.

Kazu. AG6NS

[ve3lbg]

Hi Kazu/Manuel

First big thanks to Manuel also I can appreciate the work that went into this project from some past work:) and am really looking forward to getting a (tr)uSDX built.
Kazu, good work on the porting of the software I've done some coding with the Blue Pill so am somewhat familiar with the work you have done. I'm also going solo with the build of the (tr)uSDX and didn't get the boards populated. I ordered up the bare boards. I have some of the parts already and when I looked at the costing for 5 boards it didn't make sense to go the populated route. I'm ok loading the boards myself. I am getting my boards from the same source and I have used them a number of times and the turn around and quality is top notch also. I concur with your comments re Manuel's work really nicely done.

Ron VE3LBG

[Kazu.T]

Hi Ron,

This is the first time for me to order PCBs with assembly. I usually use a heat gun to reflow my PCBs but this time I wanted to try something new. The cost of assembly sounds really cheap ($11.24 for five main boards and $10.19 for five RF boards) so total cost for 5 sets are $243.25 (includes shipping and fees, not includes 74ACT00 and 74CBT3253). Based on my calculation, total cost of single kit (not include 3D printed case) will be about $82. I will put more detailed numbers later.

Hi Manuel, Guido,

I have successfully flashed the bootloader and firmware (without RF board, rotary encoders, buttons, 74ACT00 and 74CBT3253), and OLED display shows (looks like) right information. I expected to see some error message or code, so kind of surprised. I'll continue to assemble once receiving more parts.

Kazu. AG6NS

[wa2t]

Hi Kazu,

This is what I have used on other projects: https://www.digikey.com/en/products/det ... -S/1104822? Cheaper to buy 3 x 14 = 42 pins long: https://www.digikey.com/en/products/det ... -S/1104794? so you get 3) you can cut apart. They come up to 50 pins long.

These are 4.57mm high, I am not aware of anything shorter (from US vendors anyway). I'm not sure if this extra 1.07mm over the specified part is a problem, you could always remove the plastic carrier of the mating male pin header, this is what I do in another application where I need minimum height between boards.

Hope this helps.

73,

Robert, WA2T

[wa2t]

Update to the short header discussion. I managed to find 3.5mm and 5mm height short headers on AE and ordered 10 of each. Way cheaper and I'm fairly certain one (or both) will work for the inter-board connector.

[DL2MAN]

Well, with all of them you will be able to connect the two pcb´s. No doubt.
However, I designed it for the lowest possible stacking height, and the housing along with it.
So if you want to use the 3D printed housing, you need to use the 3,5mm female headers...
If you re-design the housing or don´t use one, connector height doesn´t matter.

73 Manuel; DL2MAN

[Kazu.T]

Hi Robert,

Thank you for the header pin socket info.

I finally received remaining parts from LCSC yesterday so I resume building my (tr)uSDX.
I still can't find the shorter (3.5mm) pin header socket (as you said maybe there is no such parts available in US...), so I connected (soldered) two PCBs with pin header for now. (I have vacuum de-solder tool so no problem to remove the pins later)

During today's build, I printed the Manuel's official housing case and confirmed that the distance of the two PCBs is indeed 6mm.
So, I think the workaround is that only solder the pin header pins (without plastic part) with the 4.57mm socket. To do this, you need to have the official housing case to hold the two PCBs with correct distance. Solder the pin header socket first on RF board, then put both Main and RF board in the "Upper_Wall" and "Lower_Wall", then insert the pin header pins from Main board to the pin header socket on RF board. Then, solder the pin header pins. This process needs to be done before soldering an OLED.

Kazu. AG6NS

[Kazu.T]

Hi Manuel,

Finally I completed to build my (tr)uSDX!
This is so tiny and lightweight (only 121.53g), a mobile battery is way heavier than this

I couldn't find the same speaker (23mm diameter) so for now no internal speaker. And I also couldn't find the 3.5mm pin header socket, so just directly solder 2 PCBs with pin header for now.

So far I only tested RX (SSB and CW) and CW TX, working great!
I will try to improve the PA efficiency by changing the wire distance on toroids later.

I am so glad that finally I own the genuine uSDX rig. I will use this as a "standard reference" and compare with my other uSDX ported TRXs.

Again, thank you for this fun project, Manuel!
Kazu. AG6NS

[wa2t]

Hi Kazu and group,

Here's a link to the short headers (3.5mm and 5mm) I bought on AE: https://www.aliexpress.com/item/32994110363.html

Also, here are the speakers I bought on AE: https://www.aliexpress.com/item/32859997207.html

Saves a lot of money but long wait for "slow boat" from China to USA.

73,

Robert, WA2T

[va3rr]

I ordered my relays from Aliexpress for less than $2 CAD per relay. Let's see if I actually receive what I ordered...

[VA3HF]

I ordered my relays from Aliexpress for less than $2 CAD per relay. Let's see if I actually receive what I ordered...

I've had some bad experiences with Aliexpress vendors selling electronic components that don't meet specifications. You end up waiting for delivery and get crap you can't use and then having to order again. But it is a hit and miss.

[Faraaz VK4JJ]

Also, here are the speakers I bought on AE: https://www.aliexpress.com/item/32859997207.html

Those are 8 ohm speakers....



I ordered these from ali, 23mm 32ohm. Work fine.

https://www.aliexpress.com/item/1005003440432419.html

[wa2t]

Those are 8 ohm speakers....

Oops, yes, they are. I (perhaps incorrectly) figured they'd work, is there any story/explanation behind a 32 ohm speaker being used? I'm guessing the IO line used on the Atmega does not have such a spec, but what do I know?

Thanks.

[DL2MAN]

Look again closely to the schematics...
The 270 ohm resistor is only active, when something is in the jack (external speaker or headphones).

The speaker is driven directly by the atmega.
It's also not 5V, but more like 2,5V on the output and max current is reached at level 15 at 32 ohms. At level 12 on 8 ohms speaker ...

This is why 32 ohms.This, and a lot of practical speaker tests.

73 Manuel DL2MAN

[wa2t]

Thank you Manuel!

[wa2t]

I ordered my relays from Aliexpress for less than $2 CAD per relay. Let's see if I actually receive what I ordered...

I highly recommend using through hole relays rather than SMT relays with the pins straightened. I had a very painful experience doing this very thing on a Tulip SDR build, had numerous open circuited relay pins because of leads which did not fully penetrate the PCB/protrude from the other side. The IM43's in through hole version are $2.81 USD in single piece quantities on Digikey and in stock.

I've ordered Hongfa HFD4/5's (not the -S versions, SMT again) for this build. Same relays used on the Tulip and equivalent to the IM43's as nearly as I can tell. LCSC.com has these for $1.34 USD in single piece quantities, even less (<$1 USD) on AE.

73,

Robert, WA2T

[DL2MAN]

(...)
I highly recommend using through hole relays rather than SMT relays with the pins straightened.
(...)

I double that ! This is why the Link on my Page has changed to IM43TS (no longer IM43GR).

73 Manuel; DL2MAN

[ve3lbg]

Hi Russ/ Robert

thanks for the speaker link I've ordered a couple. I've started to look for the relays and did a quick look on Alisexpress didn't see them there, do you have a link for them or a substitute.

thanks Ron VE3LBG

[wa2t]

Hi Ron,

The IM43TS are not on AE but other places (the usual suspects) have them. If you are referring to the HFD4/5's, here you go: https://www.aliexpress.com/item/1005003560540747.html But, be forewarned, although I have studied the datasheets for both extensively, the non-latching/matching polarity gobbledy-gook in the data sheets was quite confusing, I will not be responsible for parts that do not work (although my best instincts say they are a drop-in).

73,

Robert, WA2T

[va3rr]

Ron;

I ordered my IM43GR from HONGGUIJIE Store on Aliexpress. They are the SMD type, but I know you have experience soldering this type in your ATU-10.

https://www.aliexpress.com/item/4000381 ... 4c4dzosSmg

You can also buy them from Mouser - no waiting!

[wa2t]

Ron;

I ordered my IM43GR from HONGGUIJIE Store on Aliexpress. They are the SMD type, but I know you have experience soldering this type in your ATU-10.

https://www.aliexpress.com/item/4000381 ... 4c4dzosSmg

Me too! I will have those (10) available (when they arrive) for anyone not wanting to wait for the "slow boat from China".

73,

Robert, WA2T

[ve3lbg]

:) thanks for the info, if you keep the pins straight the SMD version should be ok. it worked well on the ATU-10.

Ron VE3LBG.

[Kazu.T]

I recommend to pre-solder (tinning) the pins after straighten, before put on the PCB.
Kazu.