Wednesday 23 September 2020

Magnetic Loop Antenna Controller

With Gerard, PA2G I am working on a magnetic loop antenna.

I have started with the Magnetic Loop Controller. The design of the controller is from Loftur, TF3LJ / VE2LJX.

https://sites.google.com/site/lofturj/to-automatically-tune-a-magnetic-loop-antenna

Frederik, ON5AI provides nice DIY-kits for this design

https://en.golb.be/


The hart of the circuit is a Teensy3.2 controller. I am using a steppermotor 17HS4401, which will drive the Vacuum-C of the antenna configuration.

There will be some interesting challenges: housing of the SWR-pcb, housing of the controller, interface with the HF radio, etc.




Magnetic Loop Antenna Controller


4 x 20 character display

Status Oct. 4, 2020:





Thursday 17 September 2020

Casedemic, data against hysteria

 If you are interested in the science, statistics, graphs and numbers describing Covid-19, this video presentation of Ivor Cummins may be interesting for you:

https://youtu.be/8UvFhIFzaac

His message: Be aware of Casedemic Hysteria



Update 14-Nov-2020:



There is a second bump this autumn in The Netherlands, but not a second 'wave' as often stated by the mainstream media.

December 14, it was decided that The Netherlands go into a hard lockdown until January 19, 2021. I believe that lockdowns are not supported by science and data, gathered the last decennia, and the benefit of the measure will be very limited. But that is just an opinion.

Update 28-Jan-2021


The so called second wave still does not look like a wave to me. The hard lockdown in The Netherlands has been extended to somewhere in March. Leaving the house after 21.00 hr. is forbidden. The average age of people passed away in The Netherlands because of Covid-19 is 83. There are no deaths because of influenza anymore.






Update: 19 Feb 2021: In spite of the fact that the mortality rate in The Netherlands is as expected, the hard lockdown continues till at least end March.

Update: 4 June 2021: Mortality rate is less than expected. Masks still mandatory. No more deaths because of influenza. 10 million people received their (at least first) vaccin. Graph  end May/begin June 2020 (no vaccins) shows identical values as end May/begin June 2021. Seasonal effect rules.


Sunday 6 September 2020

PI7CIS beacon

PI7CIS is a 2 meter / 70 cm beacon with QTH locator JO22dc (Scheveningen). The distance to my QTH is appr. 60 km.

                                                        PI7CIS

It transmits CW signals on 144.416 MHz (45 W) and 432.416 MHz (75 W). Antenna height is 42 meters ASL. More info: http://www.pa0c.nl/Pi7cis/pi7cis_vhf_beacon.htm




I was looking for a steady 70 cm signal for experimenting and improving the stability of my 28 - 432 MHz transverter and found PI7CIS. I am trying to improve the transverter's 404 MHz oscillator stability. This oscillator is not temperature compensated (TCXO or OCXO). With a small resistor-heated heatsink on top of the oscillator I try to improve the short term stablity.


                                                70 cm beacon on screen