07 August, 2023
Multi Face GPS Clock ver 2.0 setup
21 May, 2023
EA8/LA3ZA April 2023
The best bands were 30 m (29%) and in particular 10 m (65%) with a lot of contacts across the Atlantic ocean as the picture shows. In total 62 different entities/countries were contacted.
QSL via Logbook of the World.
28 April, 2023
3 tips for not blowing the finals of the QDX transceiver
But first, I do actually have experience in blowing the finals. That happended under testing prior to leaving, and all it took was 9.5 Volts for my 9 V build and what I thought was a dummy load, but which might have been an open circuit load. One BS170 developed a short between drain and gate with the result that 9.5 Volts was passed directly into the outputs of the driver IC5, 74ACT08, so IC5 blew as well.
My three tips for avoiding such failures are:
18 April, 2023
Clock cycles through chemical elements
This is screen number 39 for this clock, all of them selectable by rotating a rotary encoder. The project, with Arduino Mega hardware and software is documented on Github, where the current release is v.1.6.0 (2023-04-14).
The display also shows the full name for the element corresponding to the second, as shown above for element 3 which is Lithium. It is located in group (column) 1 and period (row) 2.
18 February, 2023
QDX Twins 80-10 m
- On top, the high-band version, 20-10 m, with a revision 4 PCB
- In the bottom, the original 80-20 m version with a revision 3a PCB
10 January, 2023
Audio delay - the unspecified parameter for ham radio transceivers
Elecraft K3: Upper trace is start of sidetone and lower trace is start of RF ~15 ms later. |
The main specification for ham radio transceivers is that the sidetone is synchronized with the keying. The delay to start of RF is only of secondary importance. All numbers should therefore be judged against the length of a dot which for instance at a morse code speed of 30 WPM is 40 ms.
Here are some measurements for the Elecraft K3 and K2 that I did in 2021 for a presentation on LDEs at the HamSci 2021 conference. A video of the presentation is also available: Long delayed radio echoes – the illusive secret of the ionosphere