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

Yaesu FT-991 reviews on gone.

Update: forget about this: there’s a duplicate eHam review link:

Text below left here for archive purposes.

Now that’s weird: just a few weeks ago or so there were a number of Yaesu FT-991 reviews on These weren’t all favorable — many owners complained about the radio sounding really bad on AM, giving the radio a 2 out of 5. Also a bit strange: the last time I scrolled through the reviews, nobody mentioned C4FM (System Fusion). It was as if nobody tried it, or even noticed C4FM was there.

FT-991I can only guess what’s going on here. False reviews from Yaesu haters? Made-up reviews from people who never ever touched the radio? If so, did the right thing – get rid of them all.

(Thanks to Joop PA9JOO for pointing this out)

New System Fusion HT: Yaesu FT-2DR

Yaesu is on a roll with System Fusion – the FT-991 will have it on board and, according to Sparky’s blog, a new portable will be expected in 2015. No FCC approval yet, no price is mentioned, and there aren’t much technical details available either.

What is clear that the FT-2DR will have a black & white (really?) touch screen. I wonder if I could operate the screen with winter gloves on. Somehow I doubt it, but operating a UV-5R under the same circumstances isn’t that easy either. Basic use won’t be a problem: the combined volume / channel selection rotary encoders will take care of that.



More quad-bands from China

In the beginning, there was Yaesu.


Wouxun joined the party:

Wouxun KG-UV950P Front

Wouxun KG-UV950P Front

Anytone popped up:quad-band 5Today Ben PA2OLD hunted down this one:

quad-band Recent
Which is a radio also sold by HYS:

quad-band 2A radio – as far as we know – offering 100% compatibility with Yaesu, up to the use of WIRES:

quad-band 4And, if you order enough of them, you put your own name sticker onto it:

quad-band 1Box it, advertise it, sell it, another brand is born! <insert applause here>

quad-band 3


Yaesu / Standard Horizon SR-70, SR-100

I ran into these colorful, channel based radios from Yaesu / Standard Horizon. Output is 10 mW only, they do FM and AFSK/FM, and use operating frequencies that are clearly tailored to the Japanese market.

When looking at the accessory list, it seems that these radios are programmable, at least to some extent. From what I understand one channel bank is used for simplex, two other banks are pre-programmed for repeater use.

Looks like fun toys to me, when these would work in our amateur bands. No pricing available, and there’s no guarantee that these radios will ever be sold in an EU or US version.

Flyer (PDF, in Japanese): SR100_SR70_Flyer
Manual (PDF, in Japanese): SR70_manual-1


SR-70 SR-100Some specs:(*)

01ch ~ 11ch : 422.0500MHz ~ 422.1750MHz
1ch ~ 9ch : 422.2000MHz ~ 422.3000MHz

10ch ~18ch :
TX freq. 440.2625MHz ~ 440.3625MHz
RX freq. 421.8125MHz ~ 421.9125MHz

12ch ~ 29ch :
TX freq. 440.0250MHz ~ 440.2375MHz
RX freq. 421.5750MHz ~ 421.7875MHz

– Modulation: F3E (FM), F2D (AFSK/FM)
– Works in simplex and repeater modes
– RF Power Output: 10mW
– Sensitivity:-8dB μV (@ 12dB SINAD)
– Audio output: 60mW (@ 4 Ω, 10% distortion)
– Operating temperature: -10℃~+ 50℃
– Power requirements: Single alkaline AA batteries (33 hours operation)
– Sold separately: nickel-metal hydride battery (39 hours operation)
– Dimensions: 57.0(W) × 88.0(H) × 16.5mm(D)
– Weight: 95g
– Waterproof and dust proof according to IP67

(*) According to my translation attempts; I might have made some errors