DL4YHF's PIC-Keyer

Last updated: August 2011

There are some other sources of information about the PIC-Keyer (especially translations into other languages):

Translations into other languages

Do you have a translation of the keyer's manual into any other language which is available "online" ? 
Please send mail to dl4yhf(at)qsl(dot)net so I can put a link on it !

Some "frequently asked questions" about the keyer

  What is the "QSK" - signal which can be found in the circuit diagram ?
This signal was once used to drive a Receive/Transmit relay in a small QRP-transceiver with a built-in keyer. Because I ran out of program memory space in the PIC, I removed some parts of the "QSK"-routines (maybe the QSK-output is still driven by the PIC, so you should leave it unconnected).

  What is the "HAND-KEY" - signal which can be found in the circuit diagram ?
When I made the circuit diagram, I thought it might be useful to connect a "straight key" (or "hand key") to the keyer for tuning purposes or for QRS. But I ran out of program memory space and so removed this function... maybe someone else wants to use this input again for his own purpose.

  I cannot adjust the CW speed in the range I prefer ... hw abt that ?
Check if the PIC runs at the clock speed for which the software was made. Make C2 (which is originally 330 pF) larger to let the PIC run slower. Or make C1 (originally 220 nF) larger. If still not satisfied, replace the speed lookup table in the PIC firmware but you will need Microchip's MPASM for that.
Good luck Carlos !

 My keyer draws more than 1 microampere during standby.. why ?
Read the information about the power-down-mode of the PIC.

Keyer doesn't stop transmitting or signal sounds strange when transmitting on certain HF bands..
Sound like lots of RF in the shack. Try better (low-inductance) blocking-C's as described on the Circuit page.

Will the firmware run on a PIC16F628 ?
There is a slightly modified firmware for the PIC16F628 with a few modifications. Because the 16F628 is cheaper now than the 16F84 (though the F628 has more RAM and program memory), you should use the 16F628 now. Beware ! These PICs are pin-compatible, but the oscillator sections are not. The difference is explained on the circuit page also.

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