kv4p HT

KV4P

About this app

NOTE: You need a kv4p HT radio plugged into USB on your phone for this app to work. See https://kv4p.com to learn how to build one!

kv4p HT is a homebrew VHF or UHF radio that makes your phone capable of voice and text communication completely off-grid with at least a Technician class amateur radio license.

The radio simply plugs into the USB C port on your Android smartphone and transforms it into a fully-fledged handheld radio transceiver. It's completely open source (GPL3): the Android app, ESP32 firmware, PCB designs, and 3D printer files.

It's small enough to fit in your pocket and take anywhere, and since it has no internal battery it's the perfect emergency radio to put in a go-bag or your car's glove compartment.

Ratings and reviews

What a brilliant idea! I've ordered the KV4P HT and I'm hoping it works well. An idea for the app to make it similar to zello would be to allow an external PTT bluetooth button and headset and also a floating ppt on screen. I'm not sure if you need the app open for it to work or not.

The app loaded and flashed the radio seamlessly. In just a few minutes I was able to transmit and receive. I have never been able to get a radio up and running as fast as this one. It was also fun to assemble. I watched some videos about soldering and by the time it was finished I was pretty confident in my work.

Didn't expect much so not too disappointed. Getting the radio module took a while. I paid the extra $5 to have them assemble it. I probably should have done that myself. Anyhow, the app refuses to connect to the radio using the provided cable. The phone sees that it has been plugged in but the KV4P app doesn't see it at all. I can't really tell if it is the app or the radio, but the light on the radio does power up so that much does seem to work. Two different phones, same result.

What’s new

* Rewritten firmware decodes packets more reliably and can act as a standalone KISS TNC + radio
* New APRS digipeating support (mesh networking)
* New APRS "Beacon to frequency" and "My position icon" settings
* Better APRS message decoding, fewer will display as "Raw"
* Squelch and filters are now previewed live so you can hear them
* Many bug fixes