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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What are the chances (Part IIa)?signal strength
Wednesday 25 August, 2010, 04:10 - Pirate/Clandestine
Posted by Administrator
Back in October 2009, Wireless Waffle brought to your attention the HF (short-wave) monitoring data produced on a quarterly basis by the ITU. Within these reports were a number of short-wave pirate stations and the original list of stations brought a lot of interest from these stations, both to see who had been 'caught' and to see how close the ITU had gotten to identifying their exact location. Based on the e-mails that were received following the article, it seems like some had hit the nail a little too closely on the head for comfort.

To see how the ITU were getting along, and who had been spotted more recently, a trawl of the montoring reports from January to June 2010 has been conducted and the results presented below. Those stations whose name is shown in CAPITALS were directly identified by the monitoring station concerned. Those in lower case have been identified using the various on-line blogs that report pirate reception.

DateTime (UTC)Freq (kHz)Monitoring StationLocationStation
03 Feb 100600-06004025Berlin, GermanyUKLaser Hot Hits
23 Feb 100000-06304025Tarnok, HungaryLaser Hot Hits
23 Feb 101830-23594025Tarnok, HungaryLaser Hot Hits
21 Apr 101830-24004025Berlin, GermanyLaser Hot Hits
02 May 100600-23594025Rambouillet, France0W10 52N01 (Baldock, UK!)Laser Hot Hits
23 May 100000-06304015Tarnok, HungaryLaser Hot Hits
16 May 101900-22125814.7Rambouillet, France0E17 52N45 (King's Lynn, UK)Radio Telstar South
16 May 100700-09155815Rambouillet, France6E11 52N30 (Zwolle, Netherlands)Orion Radio
27 Jun 100630-08205820Tarnok, HungaryOrion Radio
11 Apr 100854-09086203Vienna, AustriaRadio Scotland International
09 Feb 1010486210.2CCRM, BelgiumNetherlandsMISTI RADIO
10 Jan 101818-22466220El Casar, Spain11E24 44N27 (Bologna, Italy)Mystery Radio
20 Jan 101812-23506220El Casar, Spain11E24 44N27 (Bologna, Italy)Mystery Radio
30 Jan 1020026220Baldock, UK10E0 43N50 (Pisa, Italy)MYSTERY RADIO
28 Feb 101100-11376220Vienna, Austria11E0 44N0 (Prato, Italy)RADIO MARABU
06 Mar 101800-23506220El Casar, Spain11E24 44N27 (Bologna, Italy)Mystery Radio
21 Mar 102012-23556220El Casar, Spain11E24 44N27 (Bologna, Italy)Mystery Radio
06 Apr 101852-19176220Vienna, AustriaItalyMYSTERY RADIO
10 Apr 101900-23596220El Casar, Spain11E24 44N27 (Bologna, Italy)MYSTERY RADIO
13 Jun 101730-18006220Klagenfurt, Austria12E0 43N0 (Perugia, Italy)Mystery Radio
14 Jun 101700-19006220Rambouillet, France10E43 43N45 (Prato, Italy)MISTERY RADIO
15 Jun 100700-08006255Rambouillet, FranceNetherlandsCool AM
19 Jun 101530-16456374.1Rambouillet, France4E13 51N59 (Den Haag, Netherlands)Radio Baken 16
09 Feb 1009446299.2CCRM, BelgiumRADIO RAINBOW
30 Apr 101918-20056375Vienna, AustriaNetherlandsRadio Relmus
09 Feb 1009146376.6CCRM, BelgiumNetherlandsRADIO DUTCH WING
20 Jun 101015-16006399.9Rambouillet, France1W45 51N21 (Marlborough, UK)Laser 558 relay
11 Mar 101815-22006870El Casar, Spain9E7 45N18 (Milan, Italy)RADIO PLAYBACK INT
11 Apr 101500-17006959.9Rambouillet, France4E39 51N41 (Breda, Netherlands)Radio Jan Van Gent
03 Jan 1008007610El Casar, SpainItalyRADIO AMICA
10 Apr 100600-21157610Rambouillet, France12E56 43N55 (Pesaro, Italy)RADIO AMICA
11 Apr 100530-06007610Rambouillet, France12E56 43N55 (Pesaro, Italy)RADIO AMICA
10 Apr 101247-14077610Vienna, Austria11E30 44N30 (Bologna, Italy)RADIO AMICA

Please be assured that it is not our intention to name and shame these stations in any way, nor is the Wireless Waffle team opposed to hobby broadcasting (for want of a better word) but we do believe that the stations concerned should be aware that their location may not be as secret as they had hoped.

The question of how accurate these measurements are is a good one. The level of concern that seemed to arise from the previous list suggests that they may be relatively good. However, let's take a real example. There are 10 measurements relating to Mystery Radio. Of these, five different locations are logged. The map below shows the position of these loggings.

mystery radio italy

to catch a pirateThe distance between the closest of all these measurements is around 20 miles (32 km). It is possible that this is the best resolution that some of the monitoring stations can achieve. At this kind of resolution, a ground-based receiver would be unlikely to hear the transmitter. Ground wave signals would not travel this far, and it is the ground wave signal which is required for a person on the ground to be able to 'home in' on the location of a transmitter.

So should pirate radio stations be concerned about being tracked down as a result of the work of the ITU. From the evidence above, it seems that this data alone is probably insufficient to allow a station's location to be identified in one simple move. However, if you are running one of these stations and the location which is shown is more accurate than those for Mystery Radio - and certainly if its within 5 km at which point a man on the ground would be able to track you down - perhaps it's time to up sticks and find a new site!
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