Ruuvitag: Shunt capacitor on C19 on revb71

Development 🇬🇧 Electronics & Programming
1

Hello everybody!

This is my first post on Ruuvi.
I’m a noob when it comes to electronics, I’ve bought five ruuvitag pcb’s from jlcpcb and components from digikey thinking this would be a great way to learn about soldering smd components.

It’s been quite a ride already and learned alot.
I’ve been searching high and low for an answer to the question I have right now, but couldn’t find it. I’m hopefull you guys can help me.

In the schematics for revb71 there is this one component c19 which value is NA.
The comments in the schematics say it’s a shunt capacitor.

Now I’m confused about what value this capacitor should be. Somewhere on the internet I got the idea that this capacitor could also simply be replaced by a wire bridge. Is that so?

TL;DR;
What value should C19 be?
Could I replace the capacitor with a wirebridge?

2

Hello,

I hope your project goes well :slight_smile:

Generally capacitors cannot be replaced by short circuits, but some times they can be left out.

The C19 is a placeholder for a tuning component. If after the assembly the antenna performance is poor, it can be often improved by adding a tuning component. Proper values can be determined in laboratory setting. In RuuviTags case the tuning component wasn’t needed.

TLDR, leave the C19 empty.

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