Topics

Key Wiring / Mounted Key #qcx

Kent Vanderploeg
 

If I wanted to mount a key to the QCX case, I assume I'd need to tie the wiring in to the bottom of the CW key jack?  The two pads on the bottom right of the board appear to be only for a straight key.  I was hoping to use one of these:

http://qrpguys.com/single-lever-mini

73,
Kent
W9WB

Rob French (KC4UPR)
 

Guessing no one responded on this thread?  I have a similar question.

I installed all of the stock hardware, including the keyer jack.  I'm installing the QCX in a PCB enclosure based on the QRP Guys design, and am considering how to have a direct plugin on the front for that keyer. 

Based on reviewing the schematic, I *THINK* that if you are not using the GPS header, you can use those pins to connect the dits/dahs to.  Reviewing the schematic in section 5.13 Microcontroller, it looks like microcontroller pins 18 and 19 are directly connected to several functions:  

Pin 18 - MIS0 / DAH / PPS
Pin 19 - SCK / DIT / RXD

MIS0 and SCK are used by the reprogramming interface (in-circuit programmer).

PPS and RSD are used by the external GPS function.

DAH and DIT are, of course, the keyer.

So I think MAYBE you could use jumpers from pins 2-4 (GND, RXD, PPS) of the GPS header to the ground, left/dit, and right/dah connections of your keyer.

I'm hoping someone else can confirm this, however?  What am I missing?  I see that the GPS header pins have 1K resistors between them and the microcontroller, so perhaps this will mess with shaping?

Another option might be to use pins 1, 4, 6 (GND, SCK, MIS0) of the reprogramming header for ground, left/dit, and right/dah, respectively.  Those do NOT appear to have any additional passive components between them and the processor. 

Would love to hear others' thoughts on this too.

Rob
KC4UPR 

Hans Summers
 

Hi Rob

You can connect keyer dit and dah to the GPS pps and serial data signals if you wish. The 1K resistors won't harm key-shaping which is done by a different part of the circuit and is under processor control.

73 Hans G0UPL 

On Wed, Jun 5, 2019, 21:55 Rob French (Scrape) <robert@...> wrote:
Guessing no one responded on this thread?  I have a similar question.

I installed all of the stock hardware, including the keyer jack.  I'm installing the QCX in a PCB enclosure based on the QRP Guys design, and am considering how to have a direct plugin on the front for that keyer. 

Based on reviewing the schematic, I *THINK* that if you are not using the GPS header, you can use those pins to connect the dits/dahs to.  Reviewing the schematic in section 5.13 Microcontroller, it looks like microcontroller pins 18 and 19 are directly connected to several functions:  

Pin 18 - MIS0 / DAH / PPS
Pin 19 - SCK / DIT / RXD

MIS0 and SCK are used by the reprogramming interface (in-circuit programmer).

PPS and RSD are used by the external GPS function.

DAH and DIT are, of course, the keyer.

So I think MAYBE you could use jumpers from pins 2-4 (GND, RXD, PPS) of the GPS header to the ground, left/dit, and right/dah connections of your keyer.

I'm hoping someone else can confirm this, however?  What am I missing?  I see that the GPS header pins have 1K resistors between them and the microcontroller, so perhaps this will mess with shaping?

Another option might be to use pins 1, 4, 6 (GND, SCK, MIS0) of the reprogramming header for ground, left/dit, and right/dah, respectively.  Those do NOT appear to have any additional passive components between them and the processor. 

Would love to hear others' thoughts on this too.

Rob
KC4UPR