eHam

eHam Forums => CW => Topic started by: WB5RAY on January 04, 2003, 11:04:37 PM



Title: Using an MFJ keyer on 2 Meters?
Post by: WB5RAY on January 04, 2003, 11:04:37 PM
I've got an MFJ 422D combo paddles with a keyer, and would like to figure out some way to connect this to a 2 M rig and transmit CW.  Is this possible?


Title: Using an MFJ keyer on 2 Meters?
Post by: AA1QX on January 06, 2003, 01:04:33 AM
I have worked on a 2 meter code oscillator/Microphone
input circuit recently. I am using an icom IC-T2H
handheld and Iv'e interfaced the oscillator into
the microphone input. I obtained the circuit from
the ARRL website and it basically consists of a LM555
timer that is fed into the microphone input. I would
imagine that it would be a matter of taking the keyed
output and driving this circuit which simply sends
power to the oscillator and has a provision to switch
the PTT (push-to=talk) circuit on. It also drives an external speaker so that you can hear what your sending
. This can be somewhat of a problem, in that loading the oscillator causes a bit of distortion and is a square wave to begin with. I think if the circuit was
fed with a well regulated supply it would work a little
better. I tried it out with a 12 volt regulated supply
and my brother N1WVS listened and said it sounded quite
good. The circuit is in the QST index!! search under
cw practice HT or something along that line and you will find it......


Title: Using an MFJ keyer on 2 Meters?
Post by: AA1QX on January 06, 2003, 01:22:29 AM
schematic can be found at
http://www.arrl.org/members-only/tis/info/pdf/9707053.pdf