Re: QCX20M #585 Transmitter Inoperative
|
Hi Dave
Have you checked for a short from IC3C pins 4, 10 to Ground??
I agree, testing Clk2 when it is unconnected would be a good idea.?
73 Hans G0UPL
On Thu, Dec 7, 2017 at 12:42 AM, Dave Lear <de.ne5dl@...> wrote: I have built #585 and the receive section is working along with the display and the sub menu items. The rig aligned as per the manual. The keyer and side tone are working.
?
However, the transmitter is not working. CLK0 and CLK1 are displaying quadrature wave forms. But here is no CLK2 output. I isolated IC1-pin 6 and still no output. So I decided to strip out IC1 and its associated components and substitute an Adafruit 5351 breakout board (didn’t realize that QRP Labs also has a similar breakout board). I changed the 27mHz crystal from the QCX to the Adafruit board in place of the 25mHz SMD Adafruit crystal.
?
CLK0 and CLK1 are operative but still no CLK2. I disconnected pin 6 again and still no output. Since the same condition appeared in both approaches I’m suspecting IC3 may be faulty. I do have a second Adafruit board and could try the same procedure to see if an unconnected CLK2 pin would have an output.
?
Any suggestions ?
?
73, Dave NE5DL
|
