Author: dieter

In HOERWACHE, it is possible to connect a Morse key to the sound card (microphone input) via a tone generator. However, character recognition through the Morse key is rarely successful right away. To improve control over whether the characters are properly and in good quality received in the internet browser (and thus at HOERWACHE), an oscilloscope is available.

The oscilloscope is displayed directly in the activity indicator, so it is best to initially select a band with low activity. The 27MHz band is well suited for this purpose.

Below the oscilloscope are the control buttons. Pressing the “Scope” button turns on the oscilloscope. Next to it, there is a selection field (InSig/OutSig) that determines whether the signal should be displayed at the input (input signal InSig) or at the output (output signal OutSig). On the far right, there is a slide switch that can be used to set a threshold value. This is helpful when the input signal contains short spikes that could be mistakenly interpreted by the Morse interpreter, even though they are often just disturbances. In general, setting the slide switch to a value of about 133-135 is sufficient. Signals above this threshold value will then be correctly interpreted as a signal.

The following image shows an input signal (InSig) that can be well recognized and interpreted by HOERWACHE.

And below is the corresponding output signal (OutSig) as it is fed to the Morse interpreter.

At the bottom right, there is a green bar indicating the output level of the signal. It fluctuates in rhythm with the signal. In the middle, there is the display “Threshold Signal 143/223,” indicating that the threshold value is set to 143. On the far left, the red display “PCH” shows the transmitting station’s call sign.

If everything is working correctly, the recognized characters will be displayed in the chat window for RX1. This is the best way to determine if all the entered characters are being correctly interpreted.

The oscilloscope is a great help in adjusting the connected Morse key. However, it usually takes some time for the entered characters to be correctly interpreted and displayed in the RX1 output window. This also depends on the clear “handwriting” of the transmitting operator, focusing on the correct lengths of dots, dashes, and pauses. However, the interpreter is “adaptive” and quickly adapts to the transmitting operator’s handwriting. Therefore, it always takes a short moment (a few seconds) for the characters to be correctly recognized.

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The Hoerwache radio station requires access to the microphone for broadcasting. The access needs to be configured in the Firefox settings:

Setting Permissions.
To do this, click on the security lock icon in the address bar of the page https://www.hoerwache.com.de. This will open another menu:

Clicking on the text (“Verbindung sicher”) “Connection secure” or the > arrow next to it will open another menu. Clicking on the bottom line of this menu with the text “More settings” will open a window with options for Firefox security settings. In that window, the switches for Automatic Playback, Microphone, and Popup Windows must be disabled.

By default, all switches are set to “Use Standard”. The switch for Automatic Playback is also enabled, and therefore the “Block audio” switch is enabled as well. So the “Use Standard” switch needs to be deselected, and then the switch (radio button) next to it should be set to “Allow Audio and Video.” It should look like the image above.

The same steps should be followed for the switches “Use Microphone” and “Open Popup Windows.” Allow both of these options as well. Afterwards, the window can simply be closed (there is no button to save or confirm!).

Checking the Settings
Finally, the settings can be checked through the Firefox menu “Settings – Privacy & Security.” Instead of using the menu, the page “about:preferences#privacy” can also be directly accessed.

Under the permissions section further down the page, you will find the permissions for the microphone. Clicking on the “Settings” button next to it will display the following screen form:

The page https://www.hoerwache.com.de will now be displayed in it, and the status will be set to “Allow.” You can also revoke the permission here, but then the HOERWACHE radio station will not function properly.

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The main receiver RX1

has a power switch, eight buttons for programmable fixed frequencies, one of which is fixed at a frequency of 500 kHz, a digital frequency display with adjustment capability using the mouse wheel, a large tuning knob (Tune), as well as controls for RF gain and volume.

1. Power on the device
You can determine whether the device is on or off by checking if the green light on the button is on or off.

Immediately after turning on the device, you will hear static noise from the speaker, and the selected frequency will appear on the digital frequency display. If the set frequency corresponds to one of the programmable memory slots or the 500 kHz frequency, the corresponding switch will light up.

2. Frequency display (and adjustment)
Frequencies from 400 kHz to 30 MHz are displayed here and can be adjusted using the mouse wheel.

To adjust with the mouse wheel, place the mouse pointer on the desired digit and roll the mouse wheel forward or backward. Each digit must be set individually; there is no carryover.

3. 500 kHz quick button
This button allows you to quickly select the emergency and calling frequency of 500 kHz at any time. The button lights up when 500 kHz is active.

4. Programmable memory slots
Previously selected frequencies can be stored in memory slots 1 to 7. These settings remain even after exiting the program. However, the memory slots are not cross-browser compatible and only apply to the same computer.
That means if you access the radio station with Firefox, for example, and save frequencies in it, they will not be available if you subsequently open the program with a different web browser. However, they will be available every time you access the Firefox web browser, as long as the memory slots are not overwritten or deleted.

To save a frequency, follow these steps: First, tune the receiver to a frequency, and then press Ctrl+<memory slot> to save that frequency. For example, to save on memory slot 1, you would click on memory slot 1 while holding down the Ctrl key. To recall the saved frequency, simply click on the corresponding memory button (without the Ctrl key).

5. RF Gain
– Not functional –

6. Volume
This control adjusts the volume. The maximum setting depends on the system’s settings (Windows, etc.).

There is also distance-dependent volume control, which means that the volume at which a station can be heard diminishes with distance until the station is no longer audible. The user cannot adjust the distance-dependent volume control.

7. Tune
Along with the band selection switches (located to the right of the radio room clock in the control panel), this control allows for tuning all frequencies from 400 kHz to 30 MHz.

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Frequency adjustment using the activity indicator

The quickest way to adjust the frequency is undoubtedly by using one of the preset buttons on the main receiver. However, it is not always the case that the desired frequency is stored there. In such instances, the frequency can be adjusted most rapidly using the activity indicator.

Firstly, it is necessary to select the appropriate frequency band. In this example, the desired frequency of 472 kHz (GPK’s operating frequency) falls within the medium-wave band. Our ship is located in the German Bight, so the previously announced storm warning at 500 kHz comes through weakly (indicated by a short yellow bar at 472 kHz) on the activity indicator.

To adjust the frequency to 472 kHz, simply click near the frequency of 470 kHz and then move the tuning slider to the desired position by scrolling the mouse wheel forward or backward.
If the station is already transmitting, you can rotate the tuning slider until the yellow bar below it is just visible (the red tuning slider is slightly narrower than the activity indicator bars of the stations). When a station is detected, the decoded Morse code will be displayed at the bottom of the Morse decoder (text field).
If the station is not yet transmitting, you can refer to the digital frequency display on the main receiver.

This method of frequency adjustment is significantly faster than using the display or tuning directly on the receiver.

During the test, a storm warning was being transmitted by GPK on 472 kHz.

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TransmissionMode

The Morse chat offers two operating modes: direct operation and memory operation. In direct operation, characters are entered directly from the computer keyboard to the Morse encoder. In memory operation, the characters are first entered in full (e.g., during a call) and then sent by clicking the Go! button.

Both operating modes have their advantages and disadvantages. Direct operation is particularly beneficial during a QSO, as it allows you to work with the keyboard as if using a Morse key. You can respond directly to input from the QSO partner without having to enter the entire response before sending it with Go!. This often leads to delays, which can cause uncertainty on the receiving end about whether the transmitted text has been received in its entirety. As a result, retransmissions may occur. In the worst case, both parties transmit simultaneously, resulting in an undefined jumble of Morse code on the working frequency (Simplex).

Memory operation is more cumbersome for conducting a QSO. In this mode, memory operation is clearly disadvantaged compared to direct operation and using a Morse key. However, this mode has advantages when you need to call a station multiple times, as the entire call text is retransmitted with each click of Go!. It can also be used to repeat texts that have been previously entered in direct operation.

To activate the Morse chat, the transmitter must be turned on, and the mode selector switch should be set to “Chat”.

1 TTT
Inserts the character sequence TTT TTT TTT into the text window for the Morse chat. It is not sent immediately but after clicking Go!.

2 XXX
Inserts the character sequence XXX XXX XXX into the text window for the Morse chat. It is not sent immediately but after clicking Go!.

3 CQ
Inserts the character sequence CQ CQ CQ de “own call sign” into the text window for the Morse chat. It is not sent immediately but after clicking Go!.

4 CLR
Clears the text window for the Morse chat.

5 >> Direct Operation
When activated (illuminated), direct operation is active, meaning that the characters are sent directly from the keyboard to the Morse encoder. In direct operation, the monitor tone should be turned off (MUTE) to avoid duplicate transmissions.

6 Go!
Sends the text from the Morse text window (from beginning to end).

7 Stop
Immediately stops the transmission. The text in the Morse chat window remains intact.

8 Morse Character Pitch
Allows adjustment of the pitch of the transmitted characters. This setting is only active in the NORM character mode (see point 9).

9 Character Mode
Allows selection of different Morse sounds. The following Morse sounds are currently available (as of May 2023): NORM – Normal mode, equivalent to mode A1; DAN, DAO, DHS, EAS, EJK, EJM, GCC, GKR, GKZ, and PCH – correspond to the known sounds of the mentioned coastal radio stations.

10 Morse Speed
The Morse speed can be adjusted between 30 and 240 characters per minute. It can also be changed during an ongoing transmission.

Reception Mode

Below the Morse chat for the transmitting text, there is the reception window. It displays received characters from a QSO, as well as fixed transmissions such as weather reports, etc. The main receiver (RX1) and the auxiliary receiver (RX2) each have their own window. Switching between them is done using switches 3 and 4 (see image).

1 CLR
Clicking this button clears the content of the currently displayed window.

2 CrLf
Allows inserting a line break at the cursor position in the text (CrLf = carriage return line feed).

3 RX1
Switches to the

4 RX2
Switches to the text field for the auxiliary receiver. Only the texts received with the auxiliary receiver (only 500 kHz) will be displayed.

5 Receiver Status Display
Shows which text field (RX1 or RX2) is currently active.

6 Text Field
Text field for the received texts.

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