Android Digimodes Interface Diagram

OK, OK, don't start to teach me to use a CAD software because I 'm too old for that and I am not an engineer but attorney!

I made a nice interface for using my HTC Desire S for HF Digimodes as it's piece of junk as a phone...
The schematics come in two versions, one is of extreme simplicity but the second has to be fine tuned to work with the phone.
As you may know, the Android phone is made to be also a music player so it has a stereo output. This is the key for making the PTT circuit. One channel is for modulation and the second one is for detecting and for PTT circuit. I used a double detector to have a sufficient voltage to trigger the 2n2222 PTT transistor, in Open Collector circuit. If you transceiver use a negative voltage for PTT, the schematic is simple to transform.

The second version use the same circuit for audio In/Out but have a small preamplifier for the audio before the detection is made. This is suitable for low volume Android devices and uses the approximative 3 V from the microphone. The input of the Android device is not using a condenser microphone, therefore we can use that DC.
The preamplifier is made with a 2N2222 transistor and it may be necessary to tweak the positive polarisation for a better result.

As a response to a comment from Catalin, YO3FVR (TNX!) , I must admit that, indeed, there is a error in the HTC connector! 
From ring to tip, the sections are:
-Microphone / Control / AUDIO IN
-GROUND
-AUDIO OUT Right
-AUDIO OUT Left

So, I think this answer to your question!
Many thanks for notice me about this!

Solar Eclipse from a high altitude helium baloon - Eclipser 1

Life is boring! What can we do to improve it? To have some excitement?
Simple!
Plan a helium balloon launch in the middle of a total solar eclipse!
Well, this is in Australia! On the other side of the Earth!
So what?
A mixed team of Romanians and Australians launched one of the most interesting high altitude balloons, right in the middle of a solar eclipse, in november 2012.
The project was managed by Stiinta si Tehnica and the main sponsor was DURACELL.
The balloon has the burst at almost 37.000 m a.s.l. and was tracked via APRS.
The antenna was an exclusive project for this kind of missions from Radioamateur's Club YO3KSR in Bucharest.
I missed this year's eclipse due to some technical problems with my Australian Visa (granted at 20th of November, after the flight...) but, who knows? Maybe i'll catch it next year!

Enjoy the video from the onboard camera:

The Quest for perfect portable HF Digital setup

I found on Android Store a nice application for my favorite PSK 31 Digimode, "PSK Droid".
Altough, it works very nice when using the phone's mic, I wanted to have also transmitting capabilities just with a Android phone.
So, i made (another) digimodes interface, with just a few components.

Look at the pictures and i will put here the schematics, later.
Of course, no battery is required for operation.

I intend to make some mods...