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 made some measurements using my miniVNApro with a simple test fixture fittig the QRP labs lowpass filters.
In case you've bricked the UNO bootloader or even the USB bootloader in the ATMEGA16U2, this may help ...
I've added a new feature to the firmware release 1.5.0 - power offset
.
The original library from Dan is not working as expected for me. So I adopted the code a little bit.
You can find the changes below. You can also download "my version" of the library here. Unzip into the Arduino's library folder.
As described here, I've build an RF Powermeter.
The basic firmware is now running. So I started analysing the accuracy of the used meter head.
Based on the code from Makis, SV1AFN I have created a small library to access the AD7887 ADC converter. The library is pretty simple to use.
Based on the work of Makis, SV1AFN i've build a small, stand-alone power meter with a "nice" GUI. This is the second RF head I've received from Makis. Data about the first one can be found here.
My SYMMETRICOM GPSDO 090-03861-03 with firmware release 1.0.0.2-01 has a bunch of commands available:
I've done some long term measurements on my GPSDO. The GPSDO has a RS232 based simple command interface.
This is my first power/voltage sensor I've build. It is based on an commercially available powermeter from B+G E-Tech. You can find them on eBay or their website. It provides a 90ms pulse for each Wh flown through it.
The line voltage is measured using a simple transformer and a circuit based on the schematic from OpenEnergyMonitor. The software to measure the line voltage is also from OpenEnergyMonitor embedded into my sensor framework.
For the main power distribution in my house, I also build a powersensor. The basic idea is the same as for this sensor. But the electric meter is already build into the distribution cabinet, so this power meter uses the so-called S0 bus of the power meter inside the cabinet.
My MQTT server also has some basic systems management capabilities - means the MQTT server can emit the following data to the MQTT broker:
I've done some measurements on two RF detectors - one on an older diode detector from ELDITEST and another one on an AD8307 based one
from SV1AFN.
To have a stable 10MHz reference in my shack, I've ordered a SYMMETRICOM based GPSDO from an Chinese eBay seller. It was delivered in kit form, so no issues with missing CE marking etc.
The GPSDO is build into a sturdy aluminium case with a PCB front panel and an aluminium back panel.
Last week I received my long awaited K-POD from QRP-Project in Berlin.
Inspired by the work of Richard G3CWI from SOTABEAMS and his flight decks for some QRP transceivers, I decided to build a matching one for my ELECRAFT KX3.
Starting point was a clipboard which can be found for some bucks at AMAZON. In the lower section, I can simply secure my log sheets with the strong clip.
My proof-of-concept works pretty stable - please check the status screen:
Here I've build an audio CW-filter based on the circuit from NM0S/4SQRP.
This filter works pretty well. I've done some audio analysis using a cheap soundcard from BEHRINGER and the shareware application AUDIOTESTER.
Now I've finished the Audio CW-filter I've decribed here in details.
Last year I've build the cheap Frog Sounds QRP Transceiver. This transceiver has a pretty basic audio section - a simple LM386 audio amplifier with some LC/RC filtering.
Inspired from the work of EA4TX and K3NG I decided to check, whether the ESP8266 based NodeMCU 1.0 (ESP-12E) is usable as a simple remote IP-based rotator control. You can get the NodeMCU in a decent quality on eBay.
Idea was, to link a local emulated serial port to the NodeMCU module. The HAM Radio applications are communicating via the standard Yaesu GS232A protocol with the emulated serial port. This emulated serial port then forwards the serial requests to the NodeMCU.
Weiterlesen: Rotator control and the NodeMCU - a proof of concept
Hier eine Sammlung unserer Wanderungen/Ausflüge der vergangenen Jahre
You may have seen my build version of the M0UKD sensor keyer and the Bamatech sensor head.
As you can see in this post, I've used a simple slide switch to control the power for the sensor keyer. This was a little bit annoying, as you must always check, whether you've turned of the power, when you leave the shack.
As power consumption is not really a big issue - the keyer draws about 2.5mA from two AA-cells. Based on the capacity of an average Energizer Classic AA battery of 1.200mA you will get an on-time of about 300h.
Since many months I've had the idea, to add an electronic switch to the keyer, so it switch of automatically after 15 minutes of idle time.
Some basic config stuff for the RASPI & MQTT
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This was my first participation in the WAG contest since 2010 - and I must say, it was a pleasure!
I managed to complete 472 QSOs all in CW :-)
2014 CW (Morse Telegraphy) was added to the German Nationwide Inventory of Intangible Cultural Heritage.
© 2019 Dietmar Krause, DL2SBA