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VanceVagell / kv4p-ht

Open source handheld ham radio project KV4P-HT
GNU General Public License v3.0
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[PCB] Design a dual-band variant #23

Open VanceVagell opened 2 weeks ago

VanceVagell commented 2 weeks ago

Design a dual VHF/UHF PCB, for use with BOTH a DRA818V and a DRA818U. The board will be larger, so needs a new 3D printed cases for this one too. I imagine this needs a diplexer on the PCB to ensure the two chips don't interfere with each other as they use the same antenna.

This will of course also require substantial updates to the Android app to show two frequencies simultaneously and other things (e.g. mute one, choose where to tx, etc.) But we can cross that bridge when the PCB exists.

myself248 commented 2 weeks ago

Two separate RF connectors could work too. It's bulky but harmless, and in some cases preferable, to have separate antennas for the two bands.

The PCB could be designed with both a diplexer and separate connectors, and the builder chooses which footprints to populate.

Working diplexer design we might want to start from: https://community.libre.space/t/2m-70cm-diplexer/2370/45

I'm game to work on this but I can't seem to find the schematic source files, only gerbers which are the compiled output. Even a screenshot would be enough to start with.

VanceVagell commented 2 weeks ago

Have fun with it! Any dual-band version will definitely be a separate fork of the project because it's more advanced, but I know people are excited by this idea. Feel free to take ownership of this enhancement request.

The current v1.6 PCB designs are linked on the Contribute page of kv4p.com, search for "EasyEDA" and you'll find it.

GunnerFreeman commented 2 weeks ago

Would it not be easier to use a singe RF module that is dual band capable like the SA868s which appears to have the same pin out so the PCB changes won't be too onerous, However both the ESP code and Android App code will have to be forked to support dual band functionality.

VanceVagell commented 2 weeks ago

Could you please link to a module that has dual-band support? I'd be really interested to take a look.

GunnerFreeman commented 2 weeks ago

Unfortunately I misread the datasheet for the SA868, it is not dual band, I am still looking for such a module.

DomTheDorito commented 1 week ago

Using 2 modules should allow for a full duplex experience. Make It small enough you could strap it to a handheld antenna such as an arrow or Elk. Id be willing to help with something like this.