G7NQL wrote: ↑03 Feb 2022, 19:08
Group buy update
Thank you to the people who have volunteered to pitch in, it's much appreciated. I'll be reaching out to you individually in due course. It's a community effort and is in line with what Guido, PE1NNZ and Manuel, DL2MAN had in mind for the radio they jointly created.
So far I have completed some dry runs on the JLCPCB service and there are some significant components which need to be substituted and one which can not, the Arduino chip which is the brain to (tr)uSDX. Hand soldering the odd capacitor or resistor is one thing though I'd suggest that the CPU is mounted and soldered by JLCPCB, having said that it is significantly larger.
In all likelihood there will be a few SMD to be manually soldered as they need to be sourced separately. These will be bagged and tagged as they're not easy to work out the values once they're off the reel.
I envisage the kit to include all components, the majority of the SMD soldered on, toroids, enamelled wire, pcb connectors and switches. The case will be optional, I haven't looked into supplying the case, it may be the case of reaching out to low volume 3D printing companies. Personally I'd prefer an aluminium case with enough space for an onboard li-ion battery, but that'll be a topic for another day.
Hi Chun,
I also tried a dummy buy for the PCBs in the last 10 minutes, as you say, the MCU is the main issue. Those out of stock capacitors can be replaced by other manufacturers. So, the mainboard has resistors and capacitors 0603 size, any NP0 can be replaced by C0G, you need to keep the voltage the same or higher. The RF board has 0805 footprints, you can take your pick of 0603 or 0805, same rules on voltage. If I can be of help on this don't hesitate to call me on the number I emailed you.
As for the MCU, it's really interesting that JLCPCB are charging so much for a device that was available for £2.12 each in x50 volume in the UK, I guess that's the law of supply and demand! Anyway, you have a choice, either keep checking to see if it comes back in stock, or try something based on this thread
viewtopic.php?t=71 although those options appear to also be out of stock, so maybe you are stuck. The other day when I checked they had stock, and I know people spoke about them being out of stock previously, so perhaps like I say, keep checking as it seems to change daily. They can be had from ebay, UK sellers appear to charge about £6.25 each, with discount for quantity. I don't know anything about the sellers. I bought 2 from ebay to replace a couple that were bricked. I think I'd be leery about getting 50 from ebay myself, but here's an option, order the PCBs with what you can get on them and let the recipients deal with that risk, alternatively, like I said, keep checking on JLCPCB on a daily basis.
I recommend buying the ferrite from kitsandparts in USA, I received 500 T37-2 and 150 FT37-43 after 8 working days at a cost of £100! Dare I say, without VAT! You will see Manuel quoting 419 euros to buy from Germany. The encoder, sma, oled, speaker, etc I got from aliexpress and haven't had any failures yet. The female 3.5mm socket can be hard to get hold of, but there is a UK company that do them
https://www.toby.co.uk/board-to-board-p ... x14-AG1-G/
Good luck, 73,
Ian MM0GYX