Lyle Johnson wrote:
From my perspective, those keying circuits want to be inside the
radio, safe from harm. Is there any reason why they weren't made part
of the radio - or why I shouldn't put them in when I get my K3?
(Assuming of course I can get into that part to do so...)
The K3 accepts open collector(or open drain) to ground as inputs, or can
be driven with 0 <= x <= +5 volts.
Some stations use RS232 levels (which can be as high as +/- 25V) for
direct FSK. Such levels need to be converted to 5 volts for the K3
digital inputs. Further, RS232 specifies a "1" as -3 < x < -25V and a
"0" as +3 < x < +25V, so a polarity inversion (in hardware or software)
is also required.
hi Lyle - I appreciate that - but I believe that in 2007 the chances are pretty darn good that those
inputs will be driven by a station computer, and that serial port is pretty well known - kind of
like the serial port for controlling the radio, right? I'm just saying this was an opportunity to
put the level shift in the radio, and I wonder why it wasn't, and why I couldn't/shouldn't modify my
own K3? thanks! - jeff wk6i
--
Jeff Stai [EMAIL PROTECTED]
Twisted Oak Winery http://www.twistedoak.com/
Winery Blog http://www.elbloggotorcido.com/
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