Wireless Waffle - A whole spectrum of radio related rubbish
Malta Universal Frequency Telereception Instrumentsignal strength
Saturday 25 December, 2010, 15:04 - Radio Randomness
Posted by Administrator
Following the immense success of the SuSi as a piece of apparel for improving short-wave reception, it is an honour to have received an e-mail from Nicolas Sant of Malta who brings news of an increadible new development in the field. Nicolas takes up the story:
Here in Malta, the summer months are very hot and the beaches are crowded with tourists. Having walked around several beaches it seems that the 'SuSi' is very popular as I have seen many women using them, as always receiving a good reception from their boyfriends and husbands and also from passers by.
The great thing about living in Malta is that it remains warm at Christmas time and it's quite possible to spend a day on the beach even in December. Me and my friends thought that it would be interesting to try and make a more festive version of the SuSi to be worn around the Christmas period. The result is what we call the Malta Universal Frequency Telereception Instrument (or Mufti for short). I hope you like it.

christmas antenna experimentThank you for this piece of festive sunshine from the Mediterranean Nicolas.

Your Mufti looks very promising, though the close proximity of the vertical struts will serve to reduce it's effective bandwidth. The positioning of the supporting structure (particularly in the upper region), covering the Mufti will also dampen it's effectiveness as the structure tends to absorb many frequencies. We suggest that the Mufti should be clear of all obstacles, and be fully visible. Do not allow the supporting structure to be allowed to cover the Mufti up in this way.

The purpose of the furry adornment on the top of the supporting structure is unclear. Is this some kind of pre-amplifier? If so, a simple repositioning of the supporting structure should increase the signal such that no additional amplification is necessary.

Finally, we do give a solid thumbs-up to the connector that you have used. It is clearly free of any oxidisation being nice and shiny and silver. This will ensure a good contact is made.

Anyhow, good work Nicolas. Do keep those pictures of your efforts at the SuSi coming in...
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Radio Ray Gunsignal strength
Friday 29 October, 2010, 16:06 - Radio Randomness
Posted by Administrator
Ever wondered what goes on in those increadibly high frequencies that might almost be called 'nanowave' instead of 'microwave'? Well other than a bit of use for looking at the earth from satellites (a.k.a. earth observation) the main uses tend to be military. This is partly because it becomes quite difficult (and thus expensive) to generate any kind of power at these frequencies but also because even if you do, it doesn't tend to go very far because of the poor propagation characteristics. At these frequencies, signals do not penetrate very far inside solid objects such that even the thinnest membrane will stop them dead in their tracks. Even the thin blue line of atmosphere that surrounds our fragile planet is enough to nobble extra high frequencies.

But those clever military people realised that this ability of signals to not penetrate anything very deeply might have an application other than for radio communication, navigation or any of the other uses you normally associate with the spectrum. They realised that a microwave oven at a frequency of, say, 95 GHz, would only cook the very outside of anything that was put in it (at a depth of no more than a half a milimetre) and leave the insides untouched. So you could use it to char the skin of a red pepper (or capsicum as they are known in lesser countries) whilst leaving the flesh crispy and fresh. Or you could char a peach, leaving the juicy bit inside uncooked. Or you could fire a beam at a human and make them feel as if they were on fire without actually burning them. No, seriously, not only could you do this, but this is exactly what a new line of devices being used by the military (and some other governmental bodies) are actually doing.

active denial systemKnown as the 'Active Denial System' (or ADS for short), these devices were initially designed to use for dispersing unwanted crowds gathering at military establishments, enclaves, camps or hide-outs. By blasting protestors, marauders and other such types with several hundred watts of high frequency 95 GHz microwaves in a tightly focussed beam, you can make them feel as if they are on-fire by heating up the nerve endings near the surface of the skin without heating the skin itself. This makes for a pretty good deterent and they soon move away, out of the beam.

Prisons soon realised the potential of the ADS to 'gently direct' prisoners away from certain areas too. Los Angeles County prison has installed one of these devices and according to the prison chief officer, "we likes 'em California char grilled", though it is unclear whether he was referring to his prisoners or to his burgers.

phaser gunSadly, attempts to use the device to produce instant suntans failed, partly due to the excrutiating pain involved in standing in front of the beam but also because it's completely the wrong type of radiation! Silliness aside, if such a device could be reduced in size to become handheld, it might be possible to generate enough oomph to produce a 'heat ray' beam to temporarily disable miscreants in your immediate vicinity. Now we have moved from HG Wells' martian heat rays to Gene Roddenberry's phaser guns. What with Star Trek communication devices having been introduced in the 1990s, and Star Trek style tri-corder being oh-so similar to iPhones, the time is nigh for someone to develop a real-life warp engine to propel humanity into the future. By the way, whilst you're there, could you check whether our Oidar is working and send us a message backwards through time to let us know. Ta muchly.
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When is a radio not a radio?signal strength
Wednesday 29 September, 2010, 14:36 - Radio Randomness
Posted by Administrator
When is a radio not a radio? radio cakeWhen it's a cake? Well obviously, but it wouldn't be a Wireless Waffle article if it was about cake now would it? Waffles perhaps, but cake?

Anyhow the correct answer is 'When it's a Feynman Radio'. What, I hear you ask, is a Feynman Radio. In order to answer that we have to step back in time to the works of the Maestro James Clerk Maxwell. His Electromagnetic Wave Equation is the mathematical basis of all radio signals, propagation and so forth and desribes how radio waves travel.

Maxwell's equations (in common with many) square numbers before operating on them. One of the key numbers which is in Maxwell's equation is 't' standing for 'time'. The equations describe how Electromagnetic (radio) waves change with time. However, the factor which accounts for time is squared. Now this in itself may not seem important BUT the square of a negative number is the same as the square of a positive one. So, according to Maxwell's equations, a radio wave will look identical whether it has travelled 5 seconds forwards in time or 5 seconds backwards in time! Whoa! Hang on there a minute (or minus a minute). Does this mean that every radio transmitter emits two waves, one which travels forward in time and one which travels backwards? Well that's where Richard Feynman comes in. He argues that not only is this true, but that it is true of all atomic and sub-atomic particles and that for every occurance where something travels forward in time, the same thing happens and travels backwards.

But this is rubbish right? If it were true, we would be bombarded by endless radio signals and light beams from the future. This, argue many people, is evidence that the whole idea of signals travelling backwards in time is just a mathematical theory and not a practical reality. Others argue that the whole notion of 'deja vu' is a perfect illustration of why there must be a way of seeing into the future.

But maybe the fact that we can't hear 'backwards' radio signals is down to something much more straightforward. For example:

* Radio signals travel at the speed of light. Those coming backwards from the future would cross our own path going backwards at the speed of light. We, on the other hand are travelling fowards at the speed of light. Our paths, therefore, cross at twice the speed of light which means the backwards signals would be, to all intents and purposes, invisible.

* Radio signals travelling backwards from the future would be on negative frequencies. As all existing radio receivers only tune to positive frequncies, ie those above 0 MHz, we are unable to receive them. A receiver tuned to minus 900 kHz would presumably receive future radio broadcasts perfectly well.

oidar strawkcabHere at Wireless Waffle headquarters, significant effort is being put into the development of a negative frequency radio, or an 'oidar' as we like to call it. Using things such as negative impedance converters we are seeking to synthesise a capacitor of several hundred negative picoFarads and an inductor of the appropriate number of negative microHenries such that they resonate at a negative frequency. Using a 'edoid' we hope to rectify any signals recived to feed a set of headphones. A negative antenna (an 'annetna') is proving more difficult, however we believe that a modified slot antenna in which the radiating element is a hole in a plate of metal rather than a traditional antenna which is metal in the middle of a hole (eg free space) may just do the job. Burying the annetna underground may also help but until the whole receiver is functioning it will be difficult to check.

Occasionally Wireless Waffle has been known to produce a few spoof entries (especially around April 1st!) however the Feynman Radio is real (try checking on the web). Our attempts to develop an oidar however may just be a reverse-time echo of something we failed to achieve several years from now.

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Super Signal Holiday HF Antenna Apparel (Part II)signal strength
Tuesday 27 July, 2010, 17:20 - Radio Randomness
Posted by Administrator
bikini hf antennaLast summer, here at Wireless Waffle, we came up with a design for an increadible piece of beach-wear for the short-wave listener which we cristened the 'Wireless Waffle Super Signal Holiday HF Antenna Apparel'. Not only has this become the must have item for improving reception whilst soaking up the sun, devotees have coined the nickname, 'SuSi' and it's an idea that has clearly caught on. At the end of our revelation of this unbelievable breakthrough in summer attire last year, we asked you to submit your own photos of the 'SuSi' which we would then share with other Wireless Waffle readers. And submit them you did! Here we present the 2010 SuSi Snapshot Selection. Together with the original device, it is enthralling to see so many variants in use, however we have our doubts about how effective some of the modified versions might be - so together with your photos, we have also included our view on how well the device pictured might perform.

wireless beach wearThis first picture was sent in by Jim Thrisby of Humberside and was taken in his laboratory with the device under test conditions, rather than out in the field. The unit in question has been modified to include a double, side-mounted dipole which will imbue it with some directionality. The use of an interconnecting cross-bar, however, will act as a short-circuit at higher frequencies and may limit the broadband functionality of the device. The inclusion of three distinct connection pads does, however, offer the wearer some flexibility in adopting the best position for reception whilst allowing the interconnecting wires not to get in the way.


hf antenna bikiniThis next image came from Tyrone Mulligan from South Carolina and shows a similar variant to that sent in by Jim. In this case, however, the horizontal interconnecting cross-bar is missing and its omission should ensure a wider frequency response. The three interconnection pads are also present, however the triangular (instead of square) shape and blue paint used to make them 'look pretty' may introduce a high impedance into the connection which is undesirable. The use of a conductive gel or paint will ensure a more solid contact. The modified SuSi is shown in use under good conditions and is clearly being well received by the wearer.


short wave bikiniTuning of a SuSi should not require any user intervention, however some experimenters such as Dave Brookes of Sydney, Australia, have suggested that some manual adjustment to the position of the various connecting wires can improve the clarity of reception. His photo shows a relatively standard SuSi but in which the support structure has been angled so as to increase the capture of incoming waves. Dave tells us that by using the device in this way, it is possible to receive many more short-waves and even some medium and long waves, but that effectiveness was reduced as it was too easy to get 'Chile' (or that's what we think Dave said).


cornish witch bikiniThis photo, which arrived by e-mail from Harman Tallow of Newquay, Cornwall, is apparently an attempt to use some Cornish witchcraft to improve the device's effectiveness. Whilst there addition of the two 'tuning coils' may improve the reception in some directions they also act to obscure significant amounts of the underlying support structure and may even weigh it down to produce a highly undesirable 'sag' in performance at some wavelengths. According to Harman, the field trials were relatively successful in that it was easier to mount the device on the support structure compared to the original design, but that overall, the reception was disappointing.


bikini phased arrayWe were particularly impressed by the efforts of Damian Hextonwick. Damian doesn't tell us where he's from but does indicate that using multiple devices in the form of a 'phased array' produces one of the largest increases in the achievable range of the device that he has witnessed (though we once again note the erroneous use of the bandwidth restricting horizontal cross-strut). His attempt to join four such devices together as shown in his picture, produced sufficient voltage to excite receivers which were at a significant distance from the array. Whereas it is necessary to connect directly to a single device to get its benefits, standing in close proximity to multiple interconnected devices has impressive results.


mesh satellite dish bikiniFinally, Heinz Wiedemann of North Germany has attempted to take the concept of the SuSi one step further and produce a device which can be used for satellites. By expanding upon the concept of a mesh dish, he has produced this mesh SuSi which has an integral 'low navel block' (LNB) at its lowest point which focuses incoming signals. Unfortunately, the alignment proves very critical and without careful hands-on positining of the LNB, the supporting structure becomes badly distorted leading to highly unsatisfactory reception. Heinz does add, however, that the hands-on nature of this variant of the SuSi has many distinct benefits which he then refuses to scientifically quantify, rendering the results of his experiments somewhat suspect.


Overall, we have been highly impressed by the look, feel and ingenuity of the various models of SuSi that have been submitted to us. Please keep up the experiments and remember to send pictures your results to us. We can't wait to see what the next year of experimentation may bring and to share the joyous fruits of your labours and to enjoy the summer sunshine wherever you may be.
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