Review – BTech APRS-K2 Cable (TRRS/APRS)

by John ‘Miklor’

It’s long overdue, but there’s finally a TRRS/APRS cable available for radios using a standard Kenwood style K2 connector.

I’ve been wanting to get involved with APRS for a while now, and this made it extremely easy.

APRS-K2 interface cable
The APRS-K2 cable allows you to interface your handheld transceiver with your existing mobile device, including. iPhone, iPad, and Android.

One end of the cable uses the Kenwood style K2 connector, while the opposite end is aprs-xover-25terminated with a TRRS connector. Also included with the APRS-K2 is a Reverse Adapter to insure compatibility with all devices. This adapter allows cable to connect to earlier 3.5MM TRRS standards, such as Nokia.

App Driven
The APRS-K2 cable uses a virtual TNC found in several apps, such as APRSDroid,, and Pocket Packet. Plug in the cable, turn on the VOX, and you’re pretty much set to go.

Product Description
BTECH APRS-K2 TRRS / APRS Cable A simple way to start using APRS by using devices you already own. The BTECH APRS-K2 Cable will quickly connect your radio to APRS by using virtual TNC (app driven) on your tablet or device. The APRS-K2 cable is built with a custom circuit board that will automatically adjust the audio for clear packet transmissions with minimal adjustment; along with protecting your devices from strong over modulated signals.

Along with allowing APRS functionality the APRS-K2 cable can provide a simple interface gateway to allow several features to your radio!

Easily record radio conversations:
By connecting the APRS-K2 cable between your radio and any recording (line-in) device.

Use the APRS-K2 cable as a Mic In Connector:
Set up VOX on your radio to accept any form of incoming audio – such as a Push-to-talk application on a Phone – or a Line-out application from your computer.

Use the APRS-K2 cable to push transmissions over a speaker system:
Easily play audio over a intercom or speaker system from your handheld.

With a backup radio and your own ingenuity, the APRS-K2 cable can serve as an interface for a variety of applications for any amateur. Compatible with Kenwood K2 Accessory Slot Radios (such as BaoFeng, BTECH, Wouxun, TYT) Compatible with all phones, tablets, and computers with 3.5MM Audio In/Out Ports

APRS-K2 Cable
Reverse Connector Adapter
Quick Start Guide


The cable comes with a simple one page instruction sheet which should have you up and running in about 10 minutes after the appropriate app is loaded.
–  Plug in the cable
–  Set your handhelds volume control
–  Turn on the VOX
–  Set your handheld to 144.390 (US)
–  Activate the app

That’s all it takes. If you’ve been considering building an APRS cable, you might find this an easy Plus and Play alternative.

The APRS-K2 can be ordered from   Amazon, or if outside the US, you can go to their website and contact them directly.   Baofeng Tech

Too many toys, too little time.
John ‘Miklor’   K3NXU

9 comments on “Review – BTech APRS-K2 Cable (TRRS/APRS)

  1. Thanks for publishing.

    Would this cable work with Fldigi on Linux or Windows PC/Tablet, for instance to exchange teletype messages using the HT?
    It’s just an “audio” cable, isn’t it?

    Cheers, Jaap

    • Remember, though, that the *radio* is still an FM rig. RTTY over FM (for example) will work in the same way that CW over FM will work — simply as FM audio and not as a weak-signal mode.

  2. It looks like there are some electronics in the cable bump. It would be interesting to know what is in it, presumably some attenuation and D.C.blocking. There are a variety of schematics floating around — some for direct connections with no components (no electronics), some with various attenuation, but no DC blocking, and some with both.

    Are there any trimmers for level adjustments in the cable?

    I find it a bit disappointing that they didn’t include a VOX circuit (ala Skip Teller’s digivox) for keying up. Without that, the price seems a bit high for essentially an audio cable.

  3. I can never get tracking to work. Send/receive text messages works. Individual pings work and I can see the app APRS signal on my Kenwood D710. Also, can never receive the data showing other APRS stations around me. Any ideas? This is with APRSPros, APRSDroid, UV5R, and both stock and external vehicle antennas.


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