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New 80m QCX #problem #80m


Scott - N1ST
 

Hello Group,

I'm having a couple of issues with my newly born QCX.
1. I only have 2.4W output
2. The rotary encoder does nothing when pushed. 
Any help debugging would be appreciated.

Scott


George Korper
 

Last month I built a QCX and forgot to solder all the encoder pins. I missed the two toward board center.....and I had checked board by eye!


On Thu, Apr 23, 2020, 8:24 PM Scott via groups.io <n1st=yahoo.com@groups.io> wrote:
Hello Group,

I'm having a couple of issues with my newly born QCX.
1. I only have 2.4W output
2. The rotary encoder does nothing when pushed. 
Any help debugging would be appreciated.

Scott


George Korper
 

What voltage were you running?
You need at least 15-16 volts to see 5 watts on 80. 

On Thu, Apr 23, 2020, 8:43 PM George Korper via groups.io <georgekorper=gmail.com@groups.io> wrote:
Last month I built a QCX and forgot to solder all the encoder pins. I missed the two toward board center.....and I had checked board by eye!

On Thu, Apr 23, 2020, 8:24 PM Scott via groups.io <n1st=yahoo.com@groups.io> wrote:
Hello Group,

I'm having a couple of issues with my newly born QCX.
1. I only have 2.4W output
2. The rotary encoder does nothing when pushed. 
Any help debugging would be appreciated.

Scott


Scott - N1ST
 

2.4w at 13.8v.
PCB v5


Scott - N1ST
 

George,

Lol, Yup that's probably the problem.  I'll solder them tomorrow, getting late here.

Thanks!


George Korper
 

You're just a little low for 12 volts. Either remove a turn or two from L1,2,3 to get 3 watts or realize no one would hear the difference and why bother 🤗 


On Thu, Apr 23, 2020, 8:49 PM George Korper via groups.io <georgekorper=gmail.com@groups.io> wrote:
What voltage were you running?
You need at least 15-16 volts to see 5 watts on 80. 

On Thu, Apr 23, 2020, 8:43 PM George Korper via groups.io <georgekorper=gmail.com@groups.io> wrote:
Last month I built a QCX and forgot to solder all the encoder pins. I missed the two toward board center.....and I had checked board by eye!

On Thu, Apr 23, 2020, 8:24 PM Scott via groups.io <n1st=yahoo.com@groups.io> wrote:
Hello Group,

I'm having a couple of issues with my newly born QCX.
1. I only have 2.4W output
2. The rotary encoder does nothing when pushed. 
Any help debugging would be appreciated.

Scott


Adam Allen
 

First thing I would check that all five tabs are soldered on the encoder.  If they look ok maybe even reflow them to be sure.  You can then check continuity at the two tabs when the button is pushed. That should rule out a faulty encoder button.  If it’s still not working you’re have to begin tracing the circuit path for those two encoder button tabs.  


Hope this helps


Christiaan PA3FUN
 

Hi Scott.
I'm using my QCX-80 for about half a year now. Running it at just about 12V, it produces slightly over 2Watts.

Good luck fixing your encoder-issue and have fun using this little wonder!

73's Christiaan PA3FUN


Scott - N1ST
 

I missed the 2 center-most pins of the encoder.  Now it's working properly. 

I removed a couple turns from L4 and the power out increased by .5w to 2.75w @ 13.8v.  Still lower than I'd like.

Christiaan, what are you seeing for the amplitude # and # of bars on the BPF Peak with a 50ohm dummy load? I'm seeing 7 + 32, which seems a little low.


Christiaan PA3FUN
 

Hi Scott.

Pse see photo taken with QCX running at 12.0              V


Scott - N1ST
 

Christiaan,

Thanks for checking your amplitude values - we're very close.
I tweaked my BPF toroids  along with L4.  At 3.560mhz I'm now able to get:
2.39w @ 12v
3.35w @ 13.8v
4.25w @ 15.49
So, we're close on power out too.
Scott