Re: QCX Trimmer Capacitor C1

Allen Poland



My answer was too brief.  I should have pointed out that capacitors such as the trimmer has 3 contacts but one is used for component mounting stability.




From: [] On Behalf Of Jonathan Bresler
Sent: Thursday, May 17, 2018 12:07 PM
Subject: Re: [QRPLabs] QCX Trimmer Capacitor C1


Allen, Kurt,


Thank you both.

Yes, a capacitor, like a resistor or inductor, is a two terminal element.

I should have copped that immediately.

Guess what was throwing me is that the schematic shows two the same symbols for two of the three legs of C1,

so I was looking for the third, the phantom, connection.



Jonathan KC3KBE


On Thu, May 17, 2018 at 12:02 PM, Kurt Zimmerman <kurt@...> wrote:

GM Jonathan;

    I revisited the installation instructions for the QCX.  When I built both the 40m & 20m versions I simply installed C! insuring the solder connections were sound.  I understand you being careful with your parts placement as well as myself, I never found issues or problems with installation.  


Good luck on your project.



Kurt - W2MW

-------- Original Message --------
Subject: [QRPLabs] QCX Trimmer Capacitor C1
From: "Jonathan Bresler" <jonathan.m.bresler@...>
Date: Thu, May 17, 2018 11:46 am



Building a 20m QCX slowly, and enjoying every minute.

Have been checking each soldered connection as I go.

Have gonna a bit confused regarding C1 the trimmer capacitor.

The ohmmeter shows the connectivity 

  • from the inboard leg of C1 to the four pin header
  • from the center leg of C1 to ground
  • what about the outboard leg?  where does it connect.

Looking at the schematic, I cant find the connection for the outboard leg, the leg nearer the edge of the board.



Jonathan KC3KBE



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