Welcome to PA0SIM´s home page


Dedicated to Ham Radio



Triggered by the magic of radio I started as a SWL in 1973. Got my full license in 1975.

My main ham radio interests are radio technology, shortwave propagation and CW.

Doing practically 100% CW on HF (AGCW #2867, FISTS #18854), mainly rag-chewing, some DX-ing (DXCC) and now and then a contest (e.g. PACC). Only my 2m transceiver has a microphone for local chats. Always using QSK.

Operating with the excellent FTDX5000 equipped with a very good APF for reading CW signals in the noise. Antennas are a 22 meter long doublet at an average height of 6 meters, using an open line and auto tuner CG3000.

Also two orthogonal small broadband active receiving loops and two phase coherent SDR receivers are used for noise cancelling, stereo diversity noise reduction and for measuring propagation polarization behavior over frequency.

I am now (Dec. 1 2018) retired as a mixed signal electronic developer/engineer from Océ - A Canon Company.



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 (e.g. for phased array’s)

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) NoiseLesser: noise reduction software route

Last NoiseLesser update June 2015






My published ham radio articles



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

73 es cu on the bands





(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: November 30, 2018