From Newsgroup: alt.ham-radio.morse
"Jim Knoll" <
jknoll@visi.com> wrote in message news:
11shsg318d0q18@corp.supernews.com...
"Bryan" <bryan.swadenerNOSPAM@comcast.net> writes:
"Jim Knoll" <jknoll@visi.com> wrote in message >news:11sffppbursk9c9@corp.supernews.com...
Hi,
Anyone remember the DigiKey keyer circuit you could buy from the
DigiKey
company? I bought one new back in the late 1960s or maybe early 1970s
and of course got rid of it. Nuts. Wish I still had it.
Anyone still using one?
-Jim
Hi Jim,
I remember it! http://dkc1.digikey.com/US/MKT/C_Hist.html tells the
history
of Digi-Key Corporation, with mention of the keyer. Not to fret, there
are
a plethora of good keyer circuits bouncing around. I have one I built in
the
mid 70s that uses TTL chips (bought the PCB from WB4VVF) at home. I
added a
true sinewave sidetone oscillator because I didn't care for the harsh >squarewave that a 555 produces.
My latest keyer is one from the ARRL Handbook that uses CMOS logic
chips --
I made my own photoetched PC board for that one. Heck, I even homebrewed >the cabinet! I provided both built-in AC power supplies for use at home,
and
a regulator to run it from an external 12VDC supply for mobile operation.
Of course, there are all kinds of keyboard-driven keyers as well. With >software, you can drive the key input on your rig from a PC's serial
port.
A few years back, I wrote my own (using QuickBasic) that included the >capability of reading a text file. Nowadays, you can find software that >will also receive Morse.
Vy 73 es GD DX,
Bryan, WA7PRC
Hi Bryan,
Tnx fer the reply. I like your idea of the sinewave output instead of
the raspy 555 timer output. I have had other electronic devices
(microwave, etc.) that have had horribly irritating tone audio.
I was thinking of checking out the pico keyer http://www.hamgadgets.com/
as my time for full fledge tinkering has diminished some. I know many
rigs have built-in keyers but sometimes I just want to play with my
Brown Bros CTL paddle hooked up to no rig.
It seems that the CW sending and receiving software is like everything
today - make it easy for everyone to use CW. Of course we don't want to exclude those that cannot learn it or that would be discrimination ; - ) Having the auto-CW option can be good. But going back to the straight
key or paddles and exercising the brain can be good too.
73 too...
-Jim
WB0ACA
Hi Jim,
It's not terribly difficult to produce a sinewave. There are a myriad of
ways to do that -- Texas Instruments has a nice treatise on the subject
here:
http://focus.ti.com/lit/an/sloa060/sloa060.pdf. Most older rigs used
the phase shift method, using a discrete device -- like my old SB102 and
newer Kenwood TS120S. When I homebrew, I prefer to use an OpAmp in a Wien Bridge circuit that utilizes an incandescent lamp (Figure 10) to minimize distortion. They're nearly foolproof, produce less than 1% distortion, and easy to adjust the frequency over a decade by changing two equal-value resistors. I feed the output to an amplifier thru a keyed analog switch and level control potentiometer.
Info on the Pico keyer indicates it has a sidetone oscillator but doesn't
say any more than that. You might want to ask them about the type of signal
it produces... sinewave/squarewave/frequency, etc.
I've used the Brown Bros paddle -- a very nice piece indeed! My first keyer paddle was homebrewed and left a lot to be desired. When I later upgraded
to General Class at age 16, Mom bought me a chromed Vibroplex Vibrokeyer. I later purchased a gray-wrinkle finish iambic Vibrokeyer. Somewhere along
the line, I lost my old Ameco straight key, and bought a nice Nye unit (w/
Navy knob). I enjoy dragging it out now and then to prove that I can still send nearly perfect Morse at close to 20WPM. Other ops sometimes ask me
what kind of keyer I'm using and are impressed when I say it's a straight
key! lol Of course, I had a good teacher... dad was a Navy Radioman, back
when Morse was king.
73,
Bryan
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