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Date: | Wed, 19 Feb 2014 16:11:27 -0800 |
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Hi Guys,
Since there have been some questions regarding the K3/KX3 and
HamPod implementation of CW decoding, let me clarify a couple points.
The display on the K3/KX3 has two areas referred to as the V F O A
display area and the V F O B display area. Usually, these display the
related V F O frequencies respectively. When the radio is set to decode
CW, it is displayed in the V F O B display area and that display can
only show 8 characters at a time so when it is decoding CW, the text is
scrolled across that small display. Once the text scrolls across the
display, it is gone from sight. That is why most operators connect the
radio to a computer running an application to display that decoded text
where it remains on the screen for review. Internally the radio
maintains a 40 byte buffer of the decoded text and the contents of that
buffer is available through the serial port. The K3 and KX3 currently
also decode PSK31 and RTTY signals and there is talk of adding PSK63 in
the future. So with the HamPod, I can access that 40 character buffer
and speak its contents. While that sounds good at first glance, there
are issues here. I continuously read the buffer but in order to
correctly pronounce the text, I need to wait until a complete word or
block of text appears so I can sensibly speak it as a word or read it a
letter at a time in case it is a call sign or other non word. This means
there is some latency when receiving before the text will be spoken.
Normally that is good and is not a problem unless you are trying to tune
in the signal. If the signal is marginal or not properly tuned in, you
are likely to get jibberish and there can be a length of time before a
break or space comes along so I can try to format and speak that text.
Also, undecodable text is replaced by an Asterisk character within the
radio so you hear a lot of those. All these factors make tuning in the
signal a bit challenging. With experience, you begin to know what a
correctly tuned signal sounds like which helps make this easier. A
sighted user can instantly see the display as they tune in the signal
which is a tremendous help. The other frustration is that once the text
goes by, it is gone. There is no way to review it as there is when
running an application on a connected computer. I have some thoughts on
how to try to implement a better tuning mode and will add that in the
future. But despite those short comings, with a good, properly tuned
signal, it is pretty neat to hear the HamPod read the data mode text to
you.
Hope that helps,
Rob
K6DQ
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