Ich habe das Leistungsmessmodul von Oliver, DG7XO nachgebaut. Es wurde in zwei Versionen in der cqDL vorgestellt. Oliver hat mir freundlicherweise eine Platine geätzt und den AVR programmiert, so dass nur noch Löten und Mechanik angesagt war...
I made some measurements using my miniVNApro with a simple test fixture fittig the QRP labs lowpass filters.
Measurement of the signal quality of QRP-Labs U3s with low-pass filters.Transmitter output is fed into a homemade 40dB power pad. The spectrum is measured using an SIGLENT SSA3021X analyzer.
The bias voltage was about 2.6VDC and the PA voltage was abt. 7VDC.
I've read the PA bias study from Hans and tried to tweak the PA of my U3S for optimum harmonics suppression etc. The spectrum is measured using an SIGLENT SSA3021X analyzer. The power is measured using a 40dB tap and a cheap 20w Dummyload from Diamond: The tap is based on the work of OZ2CPU.
Some times ago, I found for me a solution, how to handle the unstable readings from the ADC. I've described it in this post.
In the meantime, some HAMs also build the RF powermeter based on the work of Makis, SV1AFN and myself. One if these HAMs, PA3AXA Rens, digged a little bit deeper and analysed the problem in detail. Here his description.
I've created a new firmware for the hamware AT-515 tuner.
Please check a detailled description in this manual (currently German only)
*** The RAW-Mode for the interface is no longer supported ***
Some parts are available at cost price. Please check here.
2014 CW (Morse Telegraphy) was added to the German Nationwide Inventory of Intangible Cultural Heritage.
© 2022 Dietmar Krause, DL2SBA