In 2015 I've build the Frog Sounds QRP transceiver.

This little transceiver still needs improvement:

  1. The output is still only 400mW
  2. The key-click is horrible - even with the additional audio cw-filter.
  3. The suppresion of harmonics is very bad. Check below.

If someone has any ideas how to fix this, please Diese E-Mail-Adresse ist vor Spambots geschützt! Zur Anzeige muss JavaScript eingeschaltet sein!.

Harmonics

19 03 2017 09 00 00

I ran a spectrum scan on my Frog to check for harmonics on the output signal.

The measurement was done using an Siglent SSA3021X and the FA power attenuator.

Peak   Frequency   Comment
1   7.057   Main carrier. Abt. 25dBm what is 300mW
2   14.058   1st harmonic. Abt. 19.dBc below carrier. Far too less, I must check this.
3   21.060   2nd harmonic. Abt. 40dBc below carrier. This corresponds to the regulatory authorities. But not good.
 4   28.140   3rd harmonic. Abt. 48dBc below carrier. This is fine.

2014 CW (Morse Telegraphy) was added to the German Nationwide Inventory of Intangible Cultural Heritage.

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