Protože opakovaně připojuji další dislokované pracoviště a opakovaně hledám ty samé postupy ve svých poznámkách, odložím si zde komplexnější postup a podělím se o svou praxi, která by mohla někoho inspirovat.
WireGuard patří mezí nejprogresivnější a nejpoužitelnější VPN – ten kdo v korporátním prostředí řešil třeba IPSec nebo ještě staré PPTP, případně nějaké obskurní vendorlockované řešení, tak ví jaký je problém aby vše fungovalo všude. WireGuard je velmi jednoduchý na konfiguraci a širokou podporu platforem. Klient existuje jak pro macOS, tak pro Windows, Android i iOS.
rinetd je síťový nástroj na přesměrování TCP a v nové verzi 0.70 i UDP spojení. Používám to místo portforwardingu. V kombinaci s WireGuardem tedy není nutné vystrkovat porty na veřejnou IP adresu, ale stačí se v rámci VPN dotazovat jednoho zařízení, které pak v daném segmentu větší sítě přesměrovává místně dotazy.
Konkrétní usecase (třeba): Mám od poskytovatele Internetu zpřístupněné SNMP na WiFi zařízení, kterým jsem připojený skrz jeho síť MAN připojen do Internetu. Směrem z LAN se na zařízení v MAN dostanu, ale z Internetu už nikoliv. Ve virtuálním serveru v Internetu mi běží SNMP monitoring, kterým bych zařízení v MAN síti rád dohledoval.
In spring 2019 I was asked to build an antenna which should be similar to equipment which is used by US Army and what more it should work.
After some research through sources of US military contracts and pictures there was a hot candidate for MILSAT or SATCOM antenna build: AV 2040 UHF Satellite Communication (SATCOM) Antenna from ULTRALife corporation 
There are STL  and OBJ  files for anyone who would like to print own atenna. The design is for 449,550 MHz but by adjusting lengths of active parts of the antenna it can be tunder in wide range, see below on Fig. 5
There are three formulas considering f as frequency in Hz need to be calculated to get three dimensions which are mandatory for best results:
red = (299792458 / f / 2) * 0.92 [meters]
blue = red * 1.05 [meters]
green = 299792458 / f * 0.225 [meters]
It all began with an idea to get a 3D printer for home. The original intention of the 3D printer was to print a parts for my antenna designs. Then came up the idea to print something while the printer wasn´t being used.
I got the inspiration from a sub reddit r/3D_printing to print an airplane and later I discovered a great youtube channel of Richard Mrázek where he mentioned the guys from 3Dlabprint which is a company luckily from the Brno in the Czech Republic.
The very first airplane I wanted to print was IL-2 M3 Sturmovik, it was that time the newset airplane in the shop a and the price of $20 was acceptable for some print tests.
The idea becomes reality just instantly. I very appreciate genereated .gcodes for i3 Průša´s printers. You just put the airplane in the basket, proceed paying via PayPal and in a second you are downloading .STL files and pre-generated .gcodes.
Inspired by OMs in the Czech Republic who were able to make QSOs with northern stations during the Nordic Activity Contest, I decided to take my portable rig and visit one spot near my home QTH. Unfortunately, the conditions were poor. I only heard two stations but was unable to make QSO with them. At least we started the portable season with grilled meat from a campfire 🙂
On Friday 22nd March 2019, I was invited as a professional citizen by The Committee on Security to a seminar entitled “Legal regulation of weapons in the Czech Republic and related issues of ammunition production”
Thanks to the Chairman of Committee on Security, Radek Koten many representatives from different fields were invited.
However Mrs. Dana Kovaříková (the chief representative of the European Commision) was invited to give a speech during the main programme, and once again she was unable to attend.
The first speaker was Mgr. Milena Bačkovská (from The Ministry of Interior) who presented information about upcoming changes of Czech Gun Law. She gave more details about all processes and when the amendment should be sent to the House of Commons. The appeal to the European Commison with regards to the European Firearms Directive is still in process so there is no sense of urgency. The New Czech Gun Law will not be implemented before the appeal is solved.
The Director from the Department of Environmental Hazards and Environmental Damages, The Ministry of the Environment, Ing. Karel Bláha, CSc spoked about ECHA which may result in the banning of lead in ammunition. It was said that the toxicity of lead in that form is used in bullets is not an issue. The only opportunity to keep lead in the bullets is to make sure lead is put on the exception list of toxic materials published by ECHA.
RNDr. Jiří Hynek (President of Defence and Security Industry Association of the Czech Republic) spoke about the importance of the Czech weapon industry in context of internal security of the Czech Republic and informed participants about the consequences of accepting the European Firearms Directive or the lead ban could cause.
Special thanks to Radek Musil (Sellier & Bellot) who investigated all ECHA reviews and papers. Musil reported that the ECHA report was of very poor quality and conlusions from quoted sources were misrepresented. Based on the original study which was noted in the Investigation report, he said there is no danger from the lead used in ammo production. And he also mentioned a suspicious connection between ECHA and Swedish Chemicals Agency (KEMI) which is responsible for starting this campaign.
Mgr. Pavel Černý (police ex-instructor and president of LIGA LIBE) mentioned that banning lead in ammunition could increase annual expenses for gun training more than three houndred percent.
Ing. Jakub Smetánka MPA (vice president of the LEX association) agreed with the gentlemen and lady and presented very interesting statistics about the lead used in ammo and the lack of substitutions. There is no substitue available for .22LR and lead bullets for shotguns.
Have you ever wondered how the so-called QTH Locator or WW locator is calculated and what is behind it?
Many HAMs and radioamateurs use it but ask them where their locator came from and not many can tell you. There are plenty of web based applications which overlay Google maps with a locator grid and many of them provide a calculator for conversion from other geographic coordinates to Maidenhead Locator System.
m = mobiledev();
m.Logging = 1;
lat = 50.2727514;
lon = 14.2518494;
alphabet = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','R','S'];
locator = ;
len = 4;
lon = lon + 180;
lat = lat + 90;
lon = lon / 20;
lat = lat / 10;
for i = 1:len
lon_tmp = floor(lon);
lat_tmp = floor(lat);
if mod(i,2) == 0
locator = [locator int2str(lon_tmp) int2str(lat_tmp)];
lon = (lon - lon_tmp) * 24;
lat = (lat - lat_tmp) * 24;
locator = [locator alphabet(lon_tmp+1) alphabet(lat_tmp+1)];
lon = (lon - lon_tmp) * 10;
lat = (lat - lat_tmp) * 10;
And the most amazing aspect is executing .m files on your iPhone. The disadvantage is that an internet connection is necessary for computing via the application.