toggle quoted messageShow quoted text
I would start by taking a fine solder pencil tip and reflowing
the connections on IC1. It wouldn't be the first time I saw a leg
on an SMD chip hanging a couple of thou above the foil, making
like a tiny microswitch CW key.
On 6/5/20 10:50 PM, n8iaj via groups.io
Thank you for the add. I'm really excited about building my
40 meter QCX I ordered. Got a problem that is perplexing me and I
want to pose to the group.
I'm troubleshooting on why I do not have a 700 hz tone when I go
to 8.7 BPF Alignment. So I'm using a cheap DSO 150 scope and
start tracing as by Han's troubleshooting video.
Here is the weird part, Start 8.7 BPF alignment, plug in
headphones, I start at the source for the tone output, IC1 pin 6,
I touch it with the probe - Tone comes on through earphones and my
display jumps up to 10 and allows me to peak it at 11. I remove
the probe from the pin, it all stops and my display goes down to
3, no audio.
Has anyone out here come across this? Of course, I've checked my
solder joints and values of components. All my IC's show correct
voltages but no 700 hz tone on the pins.
I sincerely ask for any suggestions and thoughts on what I can
do. I know I'm so close to getting this on the air. Not to
mention the cabinet I've been building for it.
Thanks for reading.