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These instructions are written for the layouts of cell phones; the layouts of tablets might be different.
DroidRTTY is an application to decode and encode Ham Radio RTTY (45.45 Baud) with the build in microphone/speaker or wired to your radio.
A waterfall shows the frequency spectrum of 100Hz to 2500Hz. Just slide the waterfall slider on RTTY signal and DroidRTTY will start decoding.
In transmitting mode characters can be entered trough the keyboard. 9 Macros are also available to store standard texts like "name and qth" and "station info". Macro keywords like <MY:CALLSIGN> <HIS:RCVD>, <STOP> etc. can be used in macros.

DroidRTTY now also has a logbook with ADIF export and import as well as a call search.

This manual will also be available at: http://www.wolphi.com/android-apps/droidrtty-2/droidrtty-manual and might include additions or updates not shown in the manual included with DroidRTTY.

If you have any suggestions to improve DroidRTTY or the manual please feel free to contact me at info@wolphi.com

The main screen:


The waterfall shows a frequency spectrum of 0 to 2500 Hz. A RTTY signal will show as 2 vertical lines. To decode the signal the red rectangular slider needs to be moved onto the signal.

Important. Most Android devices have a build in AGC (Automatic gain control). If the incoming Audio is too strong Android will reduce the sensitivity of the microphone and weak signals will not show up on the waterfall. The level bar on the left top of the waterfall shows the signal strength of the strongest signal on the waterfall. THIS level should not be in the red otherwise the AGC will step in.

Logbook entry fields:

8 logbook fields can be populated by touching one of the fields. A keyboard will show up and the text can be entered. Another way to populate the fields is by touching a word in the receive window. The word will be highlighted. By long-clicking one of the log entry fields the highlighted text will be copied in the log entry field. (see picture below). To add the qso into the logbook press the "add to log" button. At least a callsign and a frequency need to be entered to add the qso to the logbook. The frequency needs to be entered in Mhz. A qso on 20 meters would be for example 14.070. DroidRTTY needs tHIS format for ADIF export (described later) and to calculate the correct band. The qso time and date will be taken at the time when the "Add to log" button is pressed. The time can be saved in local time (your phones time) or UTC. Please check or uncheck the UTC settings in the settings/menu.

Receiving window:

The receiving window shows the decoded text. The window can be scrolled up and down. The window will only scroll to a newly received line when the window is scrolled to the bottom otherwise it will stay at the current viewing position. The receiving window can be cleared by pressing the green "clear screen" button on the right menu.
Long-clicking the receive window will open a "share dialog box". The received text can be send by email or send to other programs that are installed on the device and support text.

To prevent the screen from turning off, an option is programmed in the settings menu to keep the screen on (careful this will use more battery power!!) To get to the settings screen press your phones menu button and then click on the settings button. The size of the text in the receiving window can also be changed in the settings to very small, small, medium , large or extra large.

DroidRTTY uses a squelch with 3 different settings. (weak, medium and strong). If the RTTY signal is below the squelch level DroidRTTY stops to decode and no new characters will be displayed. The level bar on the receiving screen shows the strength of the received signal. DroidRTTY will start decoding when the when the level is in the green area.

DroidRTTY can be switched to "reverse" which switches the mark and space frequencies.


2 different modes are possible with DroidRTTY. 45.45baud and 170Hz which is the most common mode for RTTY in Ham Radio. The other mode is 50 baud and 450Hz shift. This mode is used by the German Weather Service. Please check the following link for their time table and frequencies.



Transmit screen:

To transmit RTTY simply press the "Start TX" button. The button will change to "Stop TX". A new edit field will appear on the bottom and text can be entered for transmit. DroidRTTY uses 9 macros for frequently used text. The macro buttons are on the right side and can be scrolled up and down (phones only – buttons are static on tablets).

RTTY uses Baudot code. Baudot code uses letters, numbers and some extra characters. The characters need to be capital letters. DroidRTTY will not transmit characters which are not Baudot characters.

Here is a list of the Baudot characters:

3 A
19 B ?
0E C :
9 D $
1 E 3
0D F !
1A G &
14 H #
6 I 8
0F K (
12 L )
1C M .
0C N ,
18 O 9
16 P 0
17 Q 1
0A R 4
5 S
10 T 5
7 U 7
1E V ;
13 W 2
1D X /
15 Y 6
11 Z
0 [..unused..]

Important: Before transmitting on the radio make sure that all alarms and key press clicks are disabled !!! You don’t want play music or other sounds on the radio. Key clicks can be usually disabled in the Android settings under "Language & Keyboard"


Edit macro screen:

A macro can be edited by long-clicking a macro button and a the macro edit screen will appear.

The following macro keywords are available:

Logbook fieldsFields taken from "log entry" in the receive window:


Fields taken from "MY info" screen (see below):


<START> – will start transmittion
<STOP> – will stop transmission and return to the receive window
<TOLOG> will add qso to log (At least the fields "Call" and "Frequency" need to be filled out)

My Info screen:

Personal information like callsign, name, age etc can be entered here. THIS data will be used in the macros. For example: the value of the call field will replace <MY:CALL> – the name field will replace <MY:NAME> and so on.

After entering the information the "ok button" on the bottom needs to be pressed.
(The phones back button will not save the information).


The logbook

The logbook stores the information entered on the receiving screen and shows them as a list on the logbook screen. Individual entries can be deleted or edited by long-clicking the entry.

The qso’s can be searched by callsign and sorted by date, callsign or frequency.

ADIF import / export

ADIF files can be imported or exported by clicking the menu button and either pressing on import ADIF or Export ADIF.

How to import/export ADIF files? DroidRTTY will create a directory "DroidRTTY" on the SD card. By clicking the export button DroidRTTY will create a file named "log.adi" in the directory "DroidRTTY". THIS file can be copied to a PC and imported in a logging program. Import ADIF has been tested with ADIF log files of the Ham Radio Deluxe software DM780 but ADIF files created by other programs should import correctly also. To import an ADIF file copy an ADIF file with the name "log.adi" into the directory "DroidRTTY" on your SD card and press the Import ADIF button. A window will show up which shows the process of the import.

The log file can also be shared by pressing the "Share ADIF" button. The ADIF file can be send by email or send to other programs that are installed (email, dropbox etc…).


The logbook edit window

By long-clicking a qso in the logbook window a context menu will show up. Select "Edit" to open the logedit window.

In the logedit window the data of an individual qso can be edited. After entering /changing the data the ok button on the bottom needs to be pressed to save the data. (the phones back button will not save the information).

Backup and Restore

The backup button in menu/settings will backup the logbook as well as all the settings to the SD card. Two files will be created on the SD Card in the directory DroidRTTY. The filename of the logbook file is logbackup.dat und the filename of the settings is backup.xml. Both files can be transferred to a different phone and imported again.

By pressing the restore button DroidRTTY will look for the previously backed up files logbackup.dat and backup.xml in the folder DroidRTTY on the SD card and overwrite the logbook and DroidRTTY’s settings.


What’s new

DroidRTTY updated to Version 2.0


Now with new layout
adjustable squelch
a new"clipboard"
& more

Learn more about DroidRTTY

DroidPSK updated to Version 3


Now with PSK63
Improved sensitivity
Faster locking & more

Learn more about DroidPSK

Morse Trainer for Android V2.0

Morse Trainer

Now with Farnsworth speed and Koch method

Learn more about Morse Trainer

HF Weather Fax for Android

After weeks of programming I finished a new Android App – HF Weather Fax.
HF Weather Fax for Android decodes weather fax 120/576 charts and satellite images through the microphone of your Android phone or tablet.
Learn more about HF Weather Fax

HF Weather Fax

DroidNavtex now in Play Store

DroidNavtex is able to decode NAVTEX messages from your receiver through the phones/tablets microphone or through a connected interface.
Special audio filters even decode very weak signals through the microphone and make DroidNavtex a very affordable alternative to high priced decoders. Learn more about DroidNavtex