Frog Sounds - Spurious emissions

I've checked this extremly simple concept for spurious emissions and whether they're compliant with the current regulations ...

Miss Mosquita - a new girl in town

Since last weekend a new QRP transceiver joined my shack I bought her used from a German HAM via the QRPFORUM community. The transceiver is one of the older projects from the DL-QRP-AG but still a neat little transceiver. It is still offered in kit-form from QRP-Project in Berlin.

Frog Sounds - Enhancements to the Frog

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

This little transceiver still needs improvement:

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

If someone has any ideas how to fix this, please This email address is being protected from spambots. You need JavaScript enabled to view it..

WSPR - last spots

Here you can find the last spots for DL2SBA on each band within the last day and the all time farest spots.

WSPR live data

Live data from my WSPR feed

WSPR some data

Here some analysis of my recorded spots data with my spot data collector. As of today there are 45.000 spots recorded in my database.

RF Powermeter - Firmware 1.7.2

I've introduced with the firmware version 1.7.1 a complexity to this project which may not be suitable to all users.

WIth the firmware version 1.7.2 I've reduced the complexity by removing the remote configuration utilities.

RF Powermeter - Unstable readings

If you are using my powermeter software in conjunction with Maki's module and have a unstable readings or sporadic extrem value changes, this is a problem of the CS pin. It may be a grounding issue - Makis is currently analysing the problem.

RF Powermeter - Firmware 1.7.1

I've developed a new firmware for my RF Powermeter. In this firmware, the user can now program for six calibration points the factors for the polynimial regression functions.

Therefor I've developed a JAVA GUI application for downloading these floating point values to the device.

*** CAUTION ***
All stuff described in this post is ONLY running on an Arduino which runs the OptiBoot bootloader. The EEPROM capability of the OptiBoot bootloader is needed for the features of firmware V1.7.1

I described here a way how to flash the OptiBoot loader on an Arduino UNO clone. For this you need an ISP or a second Arduino to act as an ISP.

WSPR first data analysis

My WSPR data collector is now running some days and I started with some basic data analysis.

The power on the bands 60m to 20m is about 100mW!

WSPR data collector

Inspired from some work found on the Internet and the full functionality of my U3S I've build an automatic spot collector. The spot collector pulls every 5 minutes my spots from WSPRnet.org and puts it into a MYSQL database for later analysis. See the schematic for this setup

WSPR - QRP-Labs U3S

My new U3S is online :-)

WSPR - QRP-Labs U3S signal quality

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.