D4D/FT8 Transceiver


Larry Lovell
 

I have been assembling the 20 Meter kit and it is very nice.  I did have an issue with a defective relay but it seems to be working well now.
However, when I check the frequency and power at the antenna, I read about 11 VPP which is good but the frequency reads 564.153 KHz not the 14.074 MHz that I expected.
Any ideas what might be happening?

Receive seems to work well, I am getting plenty of signals.

--
Larry Lovell
73's N7RGW
http://QRVTronics.com
Cell: 214-697-1729


Carl Weiberg
 

Hi Larry,
I will wait on assembly my kit until you determine the issue.

iPhone Aloha

On Jan 30, 2021, at 2:28 PM, Larry Lovell <larry.lovell76@...> wrote:


I have been assembling the 20 Meter kit and it is very nice.  I did have an issue with a defective relay but it seems to be working well now.
However, when I check the frequency and power at the antenna, I read about 11 VPP which is good but the frequency reads 564.153 KHz not the 14.074 MHz that I expected.
Any ideas what might be happening?

Receive seems to work well, I am getting plenty of signals.

--
Larry Lovell
73's N7RGW
http://QRVTronics.com
Cell: 214-697-1729

--
CW


Adam Rong
 

Larry,

The 564.153kHz output should be sort of self oscillation in the TX chain. Please measure with your oscilloscope if you have on hand to confirm. You can try to add a resistor, say 470 ohm, in parallel with L1, to check if it can fix the problem.

Thanks,
Adam


Larry Lovell
 

This is what the signal looks like with the oscilloscope.  I was expecting to see 14.074 MHz.  This is right at the antenna output.
I will add a 470 ohm in parallel with L1 and see what happens.
Since I am not totally familiar with the operation of the D4D/FT8, I am not sure what to expect.
Receive is working well and the pin 6 of the NE602 is reading 14.0733 MHz.

On Sat, Jan 30, 2021 at 2:35 PM Adam Rong <rongxh@...> wrote:
Larry,

The 564.153kHz output should be sort of self oscillation in the TX chain. Please measure with your oscilloscope if you have on hand to confirm. You can try to add a resistor, say 470 ohm, in parallel with L1, to check if it can fix the problem.

Thanks,
Adam



--
Larry Lovell
73's N7RGW
http://QRVTronics.com
Cell: 214-697-1729