Welcome to PA0SIM´s home page


Dedicated to Ham Radio


[Analog route]

[Digital Signal Processing route]

[Ordinary and Extraordinary Mode Propagation route]

[Noise Reduction software route]


My main interest is CW on short-wave, but thanks to the companies that don’t know how to design for EMC, my next interest is reducing QRM. Thanks to them I have learned thinks I would not have learned otherwise.

So you will find on these pages mainly my ideas, experiences and results on local and non-local QRM and Noise reduction.


There are four main routes:


1) Analog route

Some examples of what can be found on this route

- small active receiving loops

- dual loop antenna system

- phaser / noise canceller


2) Digital Signal Processing route (DSP route)

Some examples of what can be found on this route

- effective directivity by DSP (phasing and muting)

- two phase coherent Software Defined Radio’s (two Elecraft K2 receivers as SDR)

- ideal phaser in DSP

Some audio samples:

- enhanced stereo reception by DSP

- SSB and CW Noise Reduction

- CW filter optimized for weak signal reception


3) XO Mode Propagation route



4) Noise Reduction software route

Further development is stopped (April 2015)!






I don’t have a lot of acres for antennas. Having a small city lot and too many neighbours makes the chance of local QRM very real. Not all sources can be tackled and you have to live with these remaining sources.

You have neighbours and no local QRM? Then you are (still) very lucky.


By the way:

The level of civilization is inversely proportional to the noise level (any noise: acoustic, electromagnetic or light).

73 de Jan



(email PA0SIM) (mycall is PA0SIM)

(email PA0SIM)

(email PA0SIM)




Permission is granted to use the information and the software on this website for private, non-commercial use only. If you use the information and the software provided by my pages for non-commercial use, please make reference to the source of the information.

Using the information and the software provided by my pages for commercial use is only allowed after my explicit and personal permission.

I will not accept responsibility for any damage to your equipment through the use of this information and the software or as a result thereof.



Last update: April 20, 2015