DL2SBA - HamRadio and more

Weinschel 40dB fixed high power coaxial attenuator

I was able to get a used 40dB power attenuator from a fellow ham. It is a 250W version in a very good condition. The attenuator should be usable up to 6GHz.

Huber&Suhner 30dB pad SMA

I've bought some 30dB SMA pads from Huber&Suhner.

Here some measurements using the miniVNAtiny with vna/J:

Detailed

Chinese DC-Block

I've bought a cheap chinese DC-block on eBay for my spectrum analyser.

Here some measurements using the miniVNAtiny with vna/J:

Detailed

KiwiSDR - configuration

Here I've collected some configuration stuff for my KiwiSDR.

WSPR - WSPRlite

Today we had a meeting in our local amateur radio club ESSLINGEN P02.The topic for this meeting was WSPR.

Bernd DK9BH was the organizer of this meeting. He has ordered about 10 WSPRlites from SOTABEAMS.

I had the chance, to do same basic measurements on one of the WSPRlite units.

KiwiSDR - first impressions

Here are the first pictures of my KiwiSDR setup ...

KiwiSDR - Local SDR up and running

Check out my new KiwiSDR running:

http://dl2sba.ddns.net:8073

KiwiSDR - technical details

Here are some technical details for my KiwiSDR setup ...

WSPR - Drift problems & new synthesizer board

I've build the original QRP-labs U3S from stock. Means the supplied crystal on the PLL-based synthesiser-board.

This configuration is basically working up to 20m with a lot amount of drift, but you will get many decodes on wsprnet.org. On 6m you can also get spots - once a day :-/

RF Powermeter - Unstable reading - Reloaded

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.

RF Powermeter - Firmware 1.8.1

With the firmware version 1.8.1 there are some minor enhancements:

Offset value is displayed on main screen. "O" at the end of the unit is removed
Waveform display also correct when offset is enabled

Here are the required files:

SOTA - Working conditions

My current working conditions for SOTA are:

ELECRAFT KX3. With its build in antenna tuner it does a quite remarkable job.
For the power I use a LiFePO4 battery with 12V 6,6Ah with a build in BMS.
Microphone for the SSB contacts is the stock-mike from ELECRAFT.
For CW I use the Palm Pico Paddle.
Antenna is a HYENDFED 3-band antenna.
Flight-Deck for KX3
A 10m fibre pole from DX-Wire - MINI
Some velcro-straps

hamware - FT890 Unterstützung

Ich habe die Firmware für die Hamware Tuner um den Yaesu FT890 erweitert.

In Verbindung mit dem Logbuchprogramm UCXLog folgt der Tuner automatisch der eingestellten Frequenz.

Nähere Infos sind hier zu finden.

RF Powermeter - Uploading HMI file

The Nextion display needs the content defined in the file PowerMeter.HMI. You can either upload it with the Nextion editor via a serial link to the display or you can copy the TFT file to an SD card and put this into the socket on the Nextion display.

Switch-mode DC-DC converter

I've used one of these cheap switch-mode DC-DC converters (available on eBay for a few bucks) for my WSPR U3S transmitter. Checking the transmitted signal reveals strong spurious emissions. Hints from the QRPLabs group leads me to the cause - the DC-DC converter. Replacing it with a linear LM317 one solves the problem.

WSPR - QRP-Labs U3S bad power supply

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.

RF Powermeter - Firmware 1.8.0

With the firmware version 1.8.0 I've introduce the capability to display also the input power in Watt instead of dBm. Simply tap on the unit field on the display to toggle between dBm and Watt.

GPSDO - Distribution Amplifier

I've build a simple distribution amplifier for my GPSDO.

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