Read this before using full break-in QSK

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w-u-2-o
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Read this before using full break-in QSK

Postby w-u-2-o » Wed Apr 13, 2022 2:37 pm

This capability is only available with Thetis in combination with Protocol 2 firmware, and only on the 200D, 7000 (all variants including Andromeda) and the 8000. It first appeared in Thetis 2.6.4 and P2 firmware versions 1.6 (200D) and 1.7 (all others).

The original release notes for this capability are here: viewtopic.php?f=9&t=3049

Here is an excerpt from those release notes with the details:

A new button labeled QSK appears in the CW sub-panel of the main console when operating in CW modes (CWU or CWL). If the Protocol 2 firmware version currently loaded in your radio is older than that required (see above), the QSK button is disabled. With QSK (sometimes called “full break-in”) enabled, receiver audio can be heard between CW elements (dots and dashes). This enables monitoring activity while transmitting. It's very useful when working a split-frequency or simplex DX pileup, operating in a contest, or any time the ability to hear what's going on while sending is desired.

Clicking the QSK button to activate the QSK features causes several settings to take effect that enable optimal QSK operation. These include:

• AGC is set to Custom mode (more on this later)
• PTT is disabled (it's handled in the firmware on CW when QSK is engaged)
• Semi break-in mode is enabled, and its delay is set to zero (0).
• Since Thetis MOX is not active in QSK (necessary for quick response), there is no transmit spectral displays and NO TRANSMIT METERING. Simply turning off QSK will resume the display and metering of normal transmit behavior, either with PTT or semi-break-in.

When the QSK button is clicked to disable QSK (or when changing to a non-CW mode, including when this happens as a result of clicking a band button), everything is set back to the way it was before QSK was enabled.

While operating QSK, the sidetone level becomes tied to the monitor level, which can be set in the Setup > Transmit, monitor sub-panel, with the control labeled "TX AF". Since it is a separate control from the receiver audio, the sidetone can be adjusted to be louder or softer than the receive audio according to preference. The setting remains in effect until QSK is disabled, at which time it returns to its previous value. TX AF levels will then switch back and forth between the QSK and non-QSK setting depending on the state of the QSK button.

With QSK on your own signal is heard in the receiver while transmitting. When operating with a single VFO (i.e. not split) the tone heard is identical to the CW pitch setting, since that determines the transmitter offset in CW when in tranceive mode. Depending on the sidetone volume, it may be possible to distinguish between the two tones due to a slight time difference between them. If the transmit frequency is moved slightly away from its transceiver offset, either by changing RIT/XIT or tuning the transmitter off frequency a bit using split mode, both tones will be clearly heard at different frequencies.

You will want to experiment with the Custom-mode AGC settings to tailor QSK behavior to your liking. This is done by activating QSK, then going into Settings > DSP > AGC/ALC. The AGC settings are on the left. The following settings are a good starting place:

• Slope 5, Max Gain 100, Decay 1, Hang 12.

Additional QSK Operating Notes:

1. Although semi-break-in can be manually enabled with a delay of 0 without QSK, this results in something less than true QSK. It will work but nothing will be audible between CW elements unless sending very slowly. The new QSK mode makes use of the AGC Custom mode setting and increases the AGC hang threshold to a high enough value so that AGC hang doesn't blank out the receiver between CW elements.

2. The key-down delay (Setup > General > Options) is now limited to permit a setting no shorter than 7ms to ensure a clean CW signal. Setting it lower than this would cause key clicks to be transmitted due to keying the CW signal before the relays have fully engaged. This is not healthy for the relays, and other operators on the band will not appreciate the resulting key clicks that are produced, which may extend up and down the band for 10s of KHz. Some external amplifiers may also need a longer delay, although this setting should work with most. Check your amplifier’s manual and timing requirements before using its QSK capability. In the other direction, increasing key-down delay longer than about 10ms reduces the time available to hear signals between CW elements, defeating the purpose of QSK. Likewise, key-up delays longer than a few ms is unnecessary and you likely will find that the minimum of 1ms works fine.

3. When in QSK, the usual cycling of the MOX function in Thetis doesn't occur. As a result, checking for band boundaries doesn't happen and will not prevent you from transmitting out of band. Use caution!

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