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QCX mini: Test Equipment: 9.2 RF Power

 

9.2 Test Equipment? RF Power

How is this feature used?

If I turn on 9.2 (connected to an antenna or a dummy load) and key down, will it read emitted RF power?? Can it be used for tuning coils L1,2,3,4 to maximize output?? Or does this feature have some other purpose?

Many thanks,

Jack N8EU
 

Jack, that feature is for testing RF power output if you don¡¯t have some external means to do so. It works best on original QCX and on QCX+. On the mini ?You have to Temporarily connect a jumper to the 4 pin header installed along the back edge of the board (if you installed one), next to C47 labeled ¡°GND,DVM,RF Pwr, +12v¡±. Connect it at ¡°RF Pwr¡± and touch the other end to the C28 end of L1. Make sure a dummy load in connected to the BNC connector. Key it and read power on the display. Now having said that, you can¡¯t get to the pin header or the output point with the display attached so you have to remote the display with some wires. And you can¡¯t leave this thing connected full time¡­. So it¡¯s probably best not to even mess with it on a mini. Just use an outboard power meter or dummy load with RF detector like the QRPLabs dummy load, or of course an oscilloscope if you have one.

Good luck ¡­ Ron?

On Thu, Jun 2, 2022 at 19:22 Jack Kibelbek via <jack45458=[email protected]> wrote:
9.2 Test Equipment? RF Power

How is this feature used?

If I turn on 9.2 (connected to an antenna or a dummy load) and key down, will it read emitted RF power?? Can it be used for tuning coils L1,2,3,4 to maximize output?? Or does this feature have some other purpose?

Many thanks,

Jack N8EU

Stephen Sherer
 

On Thu, Jun 2, 2022 at 10:22 PM, Jack Kibelbek wrote:
Can it be used for tuning coils L1,2,3,4 to maximize output
Jack, tuning the coils is what I used it for when I built my QCX+. It is a "relative" output test instrument. That is all you need to tune the coils and that is exactly why it is one of the features on the QCX so additional test instruments are not needed to align and set up the QCX.

Use a standard 12v rail or input or the voltage you will use in the field. For example, in the field, I use three 18650 batteries with 12.6v nominal. This way when in the field if you feel you need to make adjustments on the fly, your base readings can be used as your comparison in the field if needed. I will remember what the output should be. I recommend not using odd voltages. Just make notes of the readings as you go with each of the coils. In other words, document the readings. In the future after all the bumps and being knocked around a little you may notice the power output changes. You then have the notes to fairly accurately return the windings the way they need to be for the desired output should they change with your expeditions over time just from use.
Steve,?
Florida

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