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Qcx+ 20mhz After 2 hours on receive no power output anymore.


brambo <terps707@...>
 

No power anymore only very less power not visable on meter.
Radio was on receive  for 2 hours  when keyed no power...
Radio switched over in tx mode when keying.
In standby mode current is 0,11amp.
Keying mode current 0,14amp.
No dry solderjoint or problems at the torois winding.

Any help is welcome.

73 Bram


Evan Hand
 

Bram,
I am really new to the QCX, so, please forgive me for any newbie mistakes.

My first thought would be to use the fault-finding section of the QCX+ manual starting on page 169.  There is a section on page 172 (6.5 RF Power Output Check) that may help.  In addition, there is the online QCX Troubleshooting guide at
https://qrp-labs.com/qcx/qcxtrouble that has a section on Transmit Signal Path that has voltages and waveforms that you can expect in both Receive and Transmit. I would start with these help files, and then post any differences that you find as to how to go about fixing the issue.

Above are just suggestions.  Others on this board may have better advice.
73
Evan
AC9TU


brambo <terps707@...>
 

Thnx for advise.....Already noticed those faultfinding sections....
 
73
 

From: Evan Hand
Sent: Thursday, July 16, 2020 12:52 PM
Subject: Re: [QRPLabs] Qcx+ 20mhz After 2 hours on receive no power output anymore.
 
Bram,
I am really new to the QCX, so, please forgive me for any newbie mistakes.

My first thought would be to use the fault-finding section of the QCX+ manual starting on page 169.  There is a section on page 172 (6.5 RF Power Output Check) that may help.  In addition, there is the online QCX Troubleshooting guide at
https://qrp-labs.com/qcx/qcxtrouble that has a section on Transmit Signal Path that has voltages and waveforms that you can expect in both Receive and Transmit. I would start with these help files, and then post any differences that you find as to how to go about fixing the issue.

Above are just suggestions.  Others on this board may have better advice.
73
Evan
AC9TU


Alan G4ZFQ
 

No power anymore only very less power not visable on meter.
Radio was on receive  for 2 hours  when keyed no power...
Radio switched over in tx mode when keying.
Bram,

Check voltages on Q1, 2, 3, 6, 4 RX and TX.
Q1-3 drains should be 12 volts TX.

73 Alan G4ZFQ


brambo <terps707@...>
 

transistor 751 broke......Replaced it and works great again..

Thnx for your advice to go int to the manual.

73 Bram