No power output


Daniel Krompholz <dgkrompholz@...>
 

I cannot get qcx-mini to output any power. 

I have already:
1. Gone through the alignment process
2. Applied extra heat with the soldering iron to the toroid winding wire at the soldering points
3. Adjusted the windings with various configurations

Please advise!

Thank you


Daniel Krompholz <dgkrompholz@...>
 

Also, I meant to add the following:

I have already
4. Ensured the test watt meter and dummy load works with another radio 
5. Successfully received and decoded cw signals when connected to an antenna

On Fri, Jul 23, 2021, 4:37 PM Daniel Krompholz <dgkrompholz@...> wrote:
I cannot get qcx-mini to output any power. 

I have already:
1. Gone through the alignment process
2. Applied extra heat with the soldering iron to the toroid winding wire at the soldering points
3. Adjusted the windings with various configurations

Please advise!

Thank you


N3MNT
 

A few spots to check  ( Circled in Yellow.)


N3MNT
 

Watt meter appears to be  VHF meter not HF.


Karl Schwab
 

I have a MFJ -894 that is both, 1.6-525 MHz, 2/20/200 W. Works well, not a laboratory instrument. 


On Fri, Jul 23, 2021, 4:50 PM N3MNT <bob@...> wrote:
Watt meter appears to be  VHF meter not HF.


Daniel Krompholz <dgkrompholz@...>
 

1. Yes, maybe the meter is not appropriate.
2. Can you elaborate on what to look for in the circled yellow spots?

Thank you!!!


On Fri, Jul 23, 2021, 4:56 PM Karl Schwab <schwab.karl@...> wrote:
I have a MFJ -894 that is both, 1.6-525 MHz, 2/20/200 W. Works well, not a laboratory instrument. 

On Fri, Jul 23, 2021, 4:50 PM N3MNT <bob@...> wrote:
Watt meter appears to be  VHF meter not HF.


N3MNT
 

Solder touch in the yellow areas.


Daniel Krompholz <dgkrompholz@...>
 

Sorry, do I understand you correctly if you mean apply solder in each of these spots?


On Fri, Jul 23, 2021, 5:58 PM N3MNT <bob@...> wrote:
Solder touch in the yellow areas.


Ronald Taylor
 

Daniel, you don't need any solder in those 4 holes that are together on one edge of the board. Those are for some pins you did not install. The other ones look like some of the toroid leads. Some of them do look like they didn't get hot enough to melt the enamel coating off the wire. Put a hot iron right on the tip of the wire and add some solder and wait till it flows down the wire to the solder pad. Hope that helps ..

Ron

On Fri, Jul 23, 2021 at 3:04 PM Daniel Krompholz <dgkrompholz@...> wrote:
Sorry, do I understand you correctly if you mean apply solder in each of these spots?

On Fri, Jul 23, 2021, 5:58 PM N3MNT <bob@...> wrote:
Solder touch in the yellow areas.


Daniel Krompholz <dgkrompholz@...>
 

Thank you all!!!


On Fri, Jul 23, 2021, 6:12 PM Ronald Taylor <wa7gil@...> wrote:
Daniel, you don't need any solder in those 4 holes that are together on one edge of the board. Those are for some pins you did not install. The other ones look like some of the toroid leads. Some of them do look like they didn't get hot enough to melt the enamel coating off the wire. Put a hot iron right on the tip of the wire and add some solder and wait till it flows down the wire to the solder pad. Hope that helps ..

Ron

On Fri, Jul 23, 2021 at 3:04 PM Daniel Krompholz <dgkrompholz@...> wrote:
Sorry, do I understand you correctly if you mean apply solder in each of these spots?

On Fri, Jul 23, 2021, 5:58 PM N3MNT <bob@...> wrote:
Solder touch in the yellow areas.


 

Hi Daniel

At risk of obvious but as i don't know your experience and people often overestimate my own, and i did not see it mentioned in this thread: did you check the continuity with ohm meter between the ends of each of L1, L2, L3, L4 that way you will know those are soldered fine. Another continuity test from one side of the first coil (check circuit diagram) to the inner of the antenna will mean that all of them are fine.

You are hearing signals, how well are they or how is the background noise at full volume, if it is there, the RX is likely just fine. 

There is a trouble shooting guide for lack of TX have you looked at that? Only problem with the it is it may require a scope of sorts to trouble shoot?   But some of the initial advice is to check the current from PSU to QCX, when doing so via ammeter make sure everything is in the right place so as not to blow fuse in DVM, this is in trouble shooting manual section too, if current is high (such as 200mA) then there is something wrong. Also the voltages on IC3 pins are mentioned, but be very careful as the pins are close together, a steady hand and good eye sight or magnifier is a must in my view, but, i'm a real amateur here so don't take any of what i say above anyone else, and I hope you get the help to get the TX working.

it seems that a non working tx is easier to fix than a non working rx, perhaps not always, so if you have RX good that's good. if there is any chance you may have blown any of Q6, Q1-Q3 during testing, because QCX is really sensitive to even quite short open circuit or intermittent high SWR. in my case i blew once when using the home brew dummy load but my patch lead had a wonky connection at the BNC. 

On 23 Jul 2021, at 20:37, Daniel Krompholz <dgkrompholz@...> wrote:

I cannot get qcx-mini to output any power. 

I have already:
1. Gone through the alignment process
2. Applied extra heat with the soldering iron to the toroid winding wire at the soldering points
3. Adjusted the windings with various configurations

Please advise!

Thank you
<PXL_20210723_203115174.jpg><PXL_20210723_203035785.jpg><PXL_20210723_202921151.jpg><PXL_20210723_203002518.jpg>


--
Love 30m and CW?
http://www.30cw.net


KEN G4APB
 

Hi Daniel,
I am always looking for the blindingly obvious but here are some stupid questions…
How do you know the qcx mini is even going into transmit mode?
I see you have a paddle connected, have you set it up as per the menu selections?
Have you been to the menu that shows your rf output power? What does it read?
Does the input current increase by several hundreds of milliamperes when you key the tx?
If you run wspr beacon mode, does it produce any rf power at all?

These things I would ask myself before fault finding.
73 Ken g4apb 


Steve Greffe - VE3SGV
 

Daniel, a wattmeter is one thing, another receiver is a totally different thing. While the QCX is connected to just your dummy load, can you hear its keyed signal in a different receiver tuned to the QCX's operating frequency?

73
Steve VE3SGV 


Alan G4ZFQ
 

Measure the voltages on Q6, Q1-Q3 both RX and TX.
That will show if it is going to TX and check some of the usual failures.
73 Alan G4ZFQ