Whispers & Screams
And Other Things

Curved Text In Gimp

Photoshop is a pretty well-known piece of software. Indeed its become so well known in the field of manipulating images its transitioned into the catch-all verb to describe the act of artificially changing a photograph. Not so well known, but to all intents and purposes just as powerful as Photoshop is GIMP. GIMP stands for (The) Gnu Image Manipulation Program and one of the best features that place it streaks ahead of Photoshop is the price. It's free.

The power packed into this freely downloadable piece of software is phenomenal. You name it, GIMP can do it. Ok so introductions over, one of the things I get asked about regularly is whether GIMP can create curved text. The answer, you've guessed it is of course yes. Let's take a look at how it's achieved.

 Let's say you have a logo which looks something like this image here on the left. Your friend, who happens to be a Dentist is looking for some help with his website branding and, let's face it, toothy the tooth does look a little isolated over there. So your friend asks if you could help him place some text around the logo to give it some punch. 

The brief is that the words "Toothsome Teeth" need to curve around the top with "Dental Services" on the bottom.

So where do you even begin? Ill explain in the rest of the post.

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Hardening The Joomla Backend

If like me, you manage one or more Joomla websites, you will no doubt be aware of the sorry lack of user friendly documentation and the appalling lack of a powerful native log facility. This seems to me to be an enormous oversight on the part of the developers however it is possible with a little jiggery pokery to get the information you need. 

I noticed recently that there were enormous amounts (1500 per day) of failed login attempts at the default backend URL (site.com/administrator/). This is to be expected of any installation like this however one cannot help but feel uneasy at the incessant minute by minute brute force dictionary attacks rolling by in the log. If your passwords are secure then you'll almost certainly be fine. If your administrator username is anything but admin, you'll be even better. Still I wasn't satisfied and I decided to call in the big guns.

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Passing Dynamic Arguments to Bash Scripts


It is possible to pass arguments to a bash script when it is called from the command line. This is the technique to use when you need to have your script carry out different actions each time it runs dependent on the input and the context. This is done by passing selected parameters to the file on the command line and these parameters are called arguments.

Lets look at an example, you may have a script called "graph.sh" that performs a particular operation on an RRD file, such as extracting the data. If you want to be able to use that script on many RRD files in many different user directories, it is best to pass the file path as an argument, so that you can use the same script for all the files to be processed.

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Understanding Polarisation

There are two major types of polarisation: Cross Polarisation (Cross-pol) and Co Polarisation (Co-pol).

Looking at cross polarisation initially, there are two types of cross polarization namely circular and linear. Within the circular realm there is the Left Hand Circular, or LHCP, or Right Hand Circular, or RHCP. This type of polarization is used in C-Band and in X-Band. One would be hard pressed to find circular polarization on Ku, K or Ka band frequencies. Linear polarization on the other hand is used frequently on Ku and Ka band antennas. With linear there are two types: Horizontal and Vertical.

What exactly is happening in the linear world that we need to know about? Before understanding how linear is used, one must understand the device being used on the satellite dish to let one signal pass while blocking the other signal. This is called the Orthogonal Mode Transducer, or OMT for short.

To use the channels that are available for satellite broadcast as efficiently as possible, both horizontal and vertical polarization (and left- and right-hand circular polarization) can be applied simultaneously per channel or frequency. In such cases the frequency of one of the two is slightly altered, to prevent possible interference. Horizontal and vertical transmissions will therefore not interfere with each another because they are differently polarized. This means twice as many programs can be transmitted per satellite. Consequently, via one and (almost) the same frequency the satellite can broadcast both a horizontal and a vertical polarized signal (H and V), or a left- and right-hand circular polarized signal (LH and RH).

The ASTRA2Connect system uses cross polarisation and our users can use this page to check the correct polarisation of their own systems. ASTRA2Connect polarisation checker.
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What is a Yagi Antenna?

Ask your average person what a Yagi antenna is and they will probably look at you with a puzzled expression. The fact is however that everybody in the UK has probably seen a Yagi antenna and in all likelihood used one at some point.

The ubiquitous TV antenna.
Example of a Yagi TV aerial.


The Yagi antenna was invented by two Japanese researchers in 1926, namely Hidetsugu Yagi and Shintaro Uda.
It is more correctly called the Yagi-Uda antenna however Mr Uda seems to have slipped off the credits somewhat.
It is an example of a subtype of antenna known as the "beam antenna" but having established that its on almost every roof in the UK, why does it interest us at Rustyice Solutions?

In recent years, telecommunications has gone through a revolution with mobile communications becoming the greatest driving force behind this. Whether you like it or not all mobile communication and by definition all radio communication requires an antenna for reception and transmission of the signal. This antenna has largely become hidden from the view of the consumer with form and function of equipments dictating that an antenna can not be visible from the outside in most equipments but they are still there and play a fundamental part in everything that we do in the mobile communications world. So what does the ugly old rooftop TV antenna have to do with todays sleek 21st century devices you may ask?

'Quite a lot' is the answer. First, lets look at the technicals of the Yagi antenna itself.

Yagi with folded dipole driven element.



The Yagi antenna is usually made up of a single driven (dipole) elelment and a reflector along with a number of parasitic elements whose size and spacing is determined by the frequencies which one wishes to receive or transmit. The size of the dipole is usually half of the wavelength (?) of the centre frequency or, if a folded dipole is used, the total length of the conductor is equal to almost 1 x ?. It is directional along the axis perpendicular to the dipole in the plane of the elements, from the reflector toward the driven (dipole) element and the parasitic elements which are also known as directors. Typical spacings between elements vary from about 1/10 to 1/4 of a wavelength, depending on the specific design and performance requirements. The lengths of the directors are smaller than that of the driven element, which is smaller than that of the reflector(s) according to an elaborate design procedure. These elements are usually parallel in one plane, supported on a single crossbar known as a boom.

Laptop USB Yagi antenna



Many of the higher end wireless networking manufacturers use emulated yagi antennas in their products today however we are sure you will agree that the coolest gizmo to get yourself a wifi signal where everybody else just simply can and will not be able to connect is this example of antenna technology at its finest over there on the left. In all, we believe, a perfect example of how technology might surge ahead at great speed every day but there really is no escape from good old fashioned antenna theory when you want to get yourself connected on the move.

At Rustyice Solutions, we have many shared years of experience in the field of HF, VHF, UHF and even SHF radio communications. If you or your business needs help getting connected on the fringes of reasonable reception via off the shelf products why not give us a call. We are sure we will be able to bring our considerable experience to bear in getting you connected. Of course you could always go for the item below which, it is said can connect to a wifi network at a range of 10 miles but youre as likely to get the jail as get connected so maybe you should just leave it to us.

The (Day of the Jackal) YAGI sniper rifle



 
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