MOREHINT.TXT Written by Nigel Ballard 28 Maxwell Road Winton, Bournemouth Dorset BH9 1DL England November 1990 Well I missed out some hints and tips from the last article, so here goes with MORE hints and scanning tips you never knew you needed! MAKING USE OF THE CAR STEREO As already mentioned in my first article, but certainly worth bringing to your attention once more. TANDY/RADIO SHACK and a whole host of other electrical retailers sell a cheap adaptor that allows you to connect your portable CD player through the car stereo by way of a dummy cassette tape. Basically, you insert the dummy tape into your player, the trailing lead plugs into your portable CD player, and hey presto you now have the audio boost that a good radio car stereo can give you. Also two or even four properly mounted car speakers is certainly going to be better than the teeny weenie one in most portable scanners. And yes, your scanner works great through these adapters. Although you may need to bridge over the left and right channel wires, or fit a mono jack unless you only want your scanner coming out of one channel in the car. THE DARK SIDE It appears that many of you liked the fact that I have in the past discussed what might be called THE DARKER SIDE of radio. I must confess myself to having a soft spot for anything covert. After all if THEY don't want us to know about something, then surely it must be worth knowing about! Am I right or what? Anyway to continue our travels through the darker side of radio, here's probably the most you have ever seen written about covert bodyworn radio installs. MORE ON COVERT KIT I have already told you how the pro's mount covert radio kit in their cars, but I never told you how the FOOTMAN or covert operative goes about communicating without attracting attention. There are many variants, and I will now outline the most popular. THE HARNESS This is the central piece of kit for the covert footman. What you have is a skin coloured nylon or leather harness that fits around your shoulders and has at least one pouch that hangs under the armpit. As most people are right handed, therefore an armed undercover person would want to reach for a side-arm on his/her left side. Thus most covert harnesses are slung under the right hand side. So in the rare case when a suited operative actually has his/her suit buttoned up, look out for a bulge where the radio is slung. I know of many services where covert radio users have their suits made to measure, they turn up for a fitting already kitted up with handgun and radio harness, and the tailor makes the measurements around the extra hardware. Double breasted suits are not favoured for two reasons, a. the normal style of a double breasted suit is rather tight around the midriff, and b. there are usually too many buttons required to correctly button up a DB suit, more importantly there are two many buttons required to undo such a suit in a hurry. If such an operative on close protection work noticed the finely machined barrel of a snipers rifle protruding from a window in the general direction of his PRINCIPAL, the last thing he needs to do is fumble about with a whole stack of fiddly buttons to gain access to his side-arm. Another fashion point worth mentioning is that DB suits worn open look very scruffy, and also leave a fairly large amount of cloth flapping around, which might also get in the way should weapons need to be drawn. A CASE IN POINT Very recently, I saw some news footage of Margaret Thatcher leaving a Sunday church service, it was a very windy day, and as the close protection man came down the stairs he was wearing an OPEN double breasted suit, clearly he had his left elbow held firm against his ribs thus stopping his side-arm getting a preview with the awaiting press cameramen. Trouble is the wind caught the other side of his jacket, the right hand side flew open revealing the covert radio and harness. WHAT GOES IN THE HARNESS? THE RADIO Of course there is a radio, it's horses for courses, ranging from single channel clear mode to multi channel DVP or CRYPTO secure modes. I won't dwell on the radio's in use other than to say the more important the PRINCIPAL under protection, the more secure the mode SHOULD be. Not always the case though. Also as the RF output is never higher than five watts, typically three. And as the human body quite happily absorbs a hefty chunk of the signal. Therefore, the transmissions do not travel very far. On occasions a mobile repeater is set up on a nearby roof-top to enable greater range, and an ALL INFORMED NET. This though is only usual if the mode is secure, as now the signal can travel some distance. SECURE The need for secure speech is paramount in the short term, and is only slightly less important after the principal had departed. The short term need is because the moves of both the principal and his/her watchers and protectors could be gauged, and weak links in the protection blanket could be made use of by any would be terrorist. The problem with the secure traffic being decoded after the event, is that pertinent operational tactics could be analysed and once again weak points could be exploited in the future. This is especially true of close protection, mainly because these people are trained to a fairly set pattern, which in itself is a rather risky approach. RECEIVING THE INCOMING TRAFFIC (THE THREE METHODS) 1/EARPHONE 2/EARMIKE 3/INDUCTION 1/ EARPHONE Not much needs to be said about this method other than wired earphones can get snagged, and are a dead giveaway to everybody else. 2/ EARMIKE This method is a bit more popular, but still has all the downfalls of the basic earphone. The only difference with the earmike is that through the patented method of bone transmission, the tiny vibrations caused by speech, and even whispers are picked up by the earmike and transmitted down to the radio. Obviously full duplex comms is out because you cannot get an earmike to receive and transmit at the same time. They do however work very well, and even very quietly spoken words are picked up well. This system is a natural for hands free VOX operated communications. If you are still a bit confused by this principle, very simply it looks like a standard earphone but also acts as a conductive microphone. This method is well favoured by the US Secret Service. 3/ INDUCTION For my money the best method. What you have is a flat induction coil set into your cloth harness. Stuck in your ear is the smallest earpiece you will ever see. Imagine a hearing aid so small that 90% of it is tucked round the bend, with only a very small part visible. They are moulded to fit snugly into the ear, and skin coloured so that a member of the public would have to be stood very close and at your side to see you had something stuck in your ear. They cost plenty, and have no volume or on/off controls. You simply open a little flap, insert a tiny hearing aid battery and off it goes. They only have a few down sides that I have ever come across. 1/ they hiss all the time, even if the matching radio is turned off 2/ people have been known to forget they had one inserted and try to insert a second one, thus standing a good chance of puncturing the ear-drum 3/ long time users have suffered high frequency deafness as a result of extended use 4/ they have been known to interfere with cinema induction sound systems (not very covert) 5/ because they are so small and rather expensive, if you loose one then you spend the next week filling out forms and explaining yourself. I have seen variants that use a clip that fits round the back of the ear and attaches to the induction earpiece by way of a short length of fine fishing line. So in essence you have a totally wireless earphone. COVERT SPEAK If your harness uses the induction method, the incoming traffic as taken care of, but what about the outgoing speech? There are two methods. Method one is a small electret microphone Wired directly to the h/held's mike socket. You can either have it stitched into the very top of your harness, or on the end of a long lead that runs down your arm. Covert operators using the first method always seem to cock their heads over to the mike side like an inquisitive parrot when speaking. Method two means you have to bring your hand up to your mouth when you want to speak. The microphone out of interest is usually held in place under the wrist by either a velcro strap or a clip that attaches to your wrist watch. THROAT-MIKE This is a spin-off from the military use of a transducer style microphone that is slung around the larynx (lower throat area) as you talk it picks up your speech and sends it to the radio. The down sides are 1/ if you have a large adams apple then they are bloody uncomfortable 2/ the speech quality is really crap, very muddy with lots of base response and no treble. It is very easy to determine covert users employing throat mikes by their muffled speech. Like the ear-mike, throat mikes are well liked by tactical firearms and SWAT units who need both hands free especially if they are handling firearms. They don't need to be so much covert as hands free. The ear-mike is by far the best solution as the hurried radio command to 'FIND' something or other can easily be interpreted as 'FIRE' if the adrenalin pumping person who issued the order is wearing a throat mike. SO THEN HOW DO YOU KEY UP YOUR COVERT RADIO? 1/microswitch 2/vox 3/pressure pad 4/switchplate 1/MICROSWITCH usually down the same arm as your microphone you have a small press to make switch in a little tube. Often they are attached to the same velcro strap. When you want to transmit you bring your hand up to your mouth, curl back a finger, push in the microswitch and speak into the mic. 2/VOX This is pretty obvious really, you might well have either an internal or external vox circuit with an adjustable gain control. Over a certain threshold, when you start to speak, the radio switches to transmit. Not very good in noisy environments. Possibly the biggest downfall of the vox principal concerns armed officers. If an armed officer gets involved in a firing incident, the vox will trip on each firing and deafen all others on the frequency. 3/PRESSURE PAD Just like those alarm mats you might have just inside your front door, when the house alarm is activated, if anyone steps on the mat, the air spaced contacts meet and the alarm is tripped. The same principle is employed for the covert operative. Usually they have a pressure strip strapped onto the elbow, when the arm is raised up past a certain point, then pressure switch is compressed in the elbow joint and the radio starts to transmit. I have found this to be the least used approach. 4/SWITCHPLATE This method is greatly favoured by firemen or anyone wearing heavy flame or NBC (Nuclear Chemical Biological) protective clothing. What you have is a switch that hooks onto your belt, it usually has an oversized pressel, thus making it easy to key-up a radio even if you have heavy gloves or mits on. This also works with covert radio users who can mount the switch on their belts underneath suit jackets. If you have thoroughly read and understood the last section, then I feel sure you now know as much, if not more on the subject than the people who actually use this type of kit! A LITTLE MORE ON COVERT CAR INSTALLATIONS As briefly mentioned in a previous article. I heard that certain OFFICIAL bodies were both experimenting and actually using the car's heated rear window element as a covert transmitting antenna. I have yet to find any written information on how to go about making such a modification. But within the last week a friend who owns one of the new Ford Granada's had his heated rear window go tits up. Tracing the wires back from the window, he found a diecast box marked FORD mounted on the inside tail-gate behind the trim. He opened it up and found it to contain several open coils and a number of capacitors etc. This has to be the blocking circuit that stops the 12 volts from the demist circuit from shooting back up to the radio. Remembering that a car radio is receive only, therefore the problem with transmitting up the wire as well as receiving must be quite a problem to overcome. Anyway I do think this area is worth some further experimentation. 1. Would a scanner work well through one of these boxes? 2. Could one of these FORD boxes be converted for scanner use? 3. Is it worth rummaging around the breakers yard looking for one of these boxes in a written off Ford and attempting to suss out how it works? Yes I think is the answer to question three anyway. I even believe there is a commercial market for any bright spark who understands chokes coils etc, and can produce a product JUST for covert scanner users. After all, the Ford box had no more than a few pennies worth of components in it. BASE ANTENNAS FOR SCANNING (reception only) Alright, so this is a subject hammered to death by everyone else, but as I feel sure that certain facts revealed in my articles will appear in the scanning press, therefore I thought it high time to say my piece. THE 16 ELEMENT DISCONE Everybody's favourite choice? Well maybe so, but it is only that by default. If you are lucky enough to have a scanner that covers 25 to 1,000 MHz without any major gaps then in all honesty, no one single omnidirectional antenna could do real justice to such a wide area of spectrum. HOW SO? Well basically, if you have a quarter wave cut to a specific frequency, then it resonates perfectly at that given freq. It has no gain, but not surprisingly no loss either. Now as we all accept that any and all coax has a loss factor, therefore by the time your feed from this imaginary quarter wave reaches the antenna socket, you WILL have a loss. So then your unity gain antenna will now be in a minus gain situation. All of you in agreement so far? OK forget pre-amps for the time being, we are talking antenna theory at present. Right, now if I swapped by quarter wave for a GAIN antenna such as a collinear, I might get 5DB gain over the quarter wave, allowing for cable loss I would still be in a plus gain situation by the time we got to the scanner. Still with the flow here? So take a discone, forgetting the top loaded element many now have, they all have one thing in common.....ZERO GAIN, in fact it is true to say that in certain areas the discone works less well than a resonant QW. So why does everybody buy them, and many pronounce them as the dogs whatsits? It's back to the matter of default. You can only afford one antenna, or maybe your landlord/parents will only allow one antenna, or maybe you think you only need one antenna? Either way the discone is a BIG compromise. And do not let smooth talking radio shop salesman tell you anything else. If you could only have one antenna, but you wanted a GOOD antenna, and gain, and the chance do to some very loose direction finding what would be your choice? THE LOG PERIODIC Most logs are sold to be used in the horizontal plane, whereas we want ours in the vertical plane, any problems with that? Only one, if you mount your log using a metal pole then the front lobe and ALL the logs inherent characteristics are going to get screwed up. Instead of a good front lobe pointing in the direction of the beam, you will instead have a pair of rabbits ears protruding either side of the beams direction. Also the gain will be affected. So rule one, use a non metal mounting pole like fibreglass. Although the log is directional, you still get a damn good signal off the sides of the beam. If you buy one of the smaller Japanese variants such as the CREATE CLP-5130, then you will have gain from 50 to a 1,000 MHz and not a pre-amp in sight. Add to your log, a good rotator and some meaty 100% screen coax and you have a scanning antenna set-up to be proud of. And as long as you didn't have a pre-amp in line, you could even transmit through it. Yes, the log is a big boys toy, but if you run something like the ICOM R7000 then don't you want to get the MAX? I have seen the grove scanner beam, it roughly copies a true log periodic, but there the similarity ends. I personally prefer the CREATE log, and for the money you get one hell of a lot of metal in the box, and the build quality is superb. I'm bored already with talking about antenna's, so now onto something else. *QUICK HINT TIME* If your scanner picks up all kinds of crud from your cars electrical system, try running through these pointers to eliminate the problem 1/ wire directly to the battery, not the cigar socket. 2/ fit auto chokes to the distributor,coil,wiper motors. 3/ Use screened DC lead to the scanner. 4/ Fit resistor spark plugs (pick a good name brand). 5/ try a ferrite ring at the scanner end of your DC lead (3 loops). 6/ Route the antenna coax and DC lead away from the engine if possible. 7/ check the screen on your coax is at least 80%. 8/ fit a new ignition coil 9/ Ford etc sell special shielding kits for some models. If all that fails to sort out the problem, sell the bloody car! COMPUTER CONTROLLING YOUR SCANNER Fine, so you have decided to computer control your scanner. Firstly, can your scanner run under computer control? Check the owners manual. A few that spring to mind are as follows: ICOM R7000 ICOM R9000 AOR AR2002 AOR AR3000 YAESU FRG-9600 JIL SX400 I can't think of anymore! ICOM R7000 Icom will sell you a CIV interface box that converts their internal logic into RS-232 format. Other than that you will have to write your own software. Many US companies sell packages offering a vast array of features including spectral displays. But all are specific to either the IBM PC or the MAC. EMP in the UK offer the SCANMASTER that approaches the problem by a different route, by putting a microprocessor in the scanmaster box, therefore you can control the SCANMASTER from ANY old computer as long as it has a serial port, and can run a terminal program, so that includes even the PSION organiser, POQET, or ATARI portfolio etc etc. R9000 What I know about this model you could write on the back of a matchbox. AOR AR2002 Without doubt the hardest bitch to control. AOR offered no help or software, and wouldn't even say what the pins on the funny connector did. A real shame as the 2002 is the PERFECT candidate for remote control. Mainly because it is so slow and awkward to use. I have only seen this model under the universal SCANMASTER control once again, the most notable thing is how far it will go below the 25 MHz lower limit when under control. And the scan speed is now much faster. AOR AR3000 Well if you read the previous article I wrote on the 3000, then you will know how easy and powerful this radio can be under remote control. YAESU FRG-9600 I think you all must know by now how much I dislike this scanner. Once again I have seen it only under SCANMASTER control, the startling thing this time is the speed of scan which really rockets along. Still a dog of a radio though. JIL SX400 I never got to try one of these early scanners. So I have no idea how they perform. I do remember hearing that they looked a lot better than they worked. DIFFERENT APPROACHES The Scanmaster type approach, gives you functional control, but lacks any of the fancy screen displays as found on dedicated packages, however you can use a scanmaster on ANY computer with a serial port, capable of running a simple terminal (comms) program. The dedicated approach, means you have to have a specific computer type, PC or MAC. For that sacrifice you get some very impressive screen displays, and lot's of pretty colours to look at. So then, if you are already a PC or MAC convert then you know what to buy, however if you only have an AMIGA,ATARI,PCW or similar games/graphics oriented machine, then the Scanmaster approach has to be for you. PROBLEMS WITH COMPUTER CONTROL 1/ Computer noise caused by cheap and poorly screened computers, especially games orientated models which can generate really nasty sproggies, these will make your scanner halt it's search modes and can be VERY annoying. 2/ Long and un-screened leads once again can induce noise from the computer back to the scanner. Good quality screened leads, the shorter the better, and a ferrite ring at either end will sort out most problems. Also try to route them away from the computer if possible. You may notice that things appear to be running slower under computer control. There are several factors involved here. a/ If your control program is written in BASIC then it may well be down to the language employed. PASCAL/C++ etc are the best. b/ the link between the scanner and computer may be set at a low baud rate. c/ your colour monitor is taking it's time with screen updates, and this is a common problem with a lot of colour computers. RUBBER DUCKS (helically wound antennas) It is a fairly natural progression to purchase a h/held scanner at one time or another. After all, who wants to be tied to the radio room all the time. So out you go and purchase a shiny new h/held. There is not much you can do to improve or customise such a radio. Better nicads as already covered. And what about the antenna. Well, if you use it in the car then connecting your scanner to an external will improve your reception greatly. If you like wandering about on foot you may be tempted to purchase one of those mega-long telescopic antennas. Why? well if you don't normally look like a prat, wandering around with a six foot telescopic antenna whipping around in the breeze will certainly give you that prat-like look. Now what about the rubber duck as supplied with the radio. Some are definitely better than others. I have a few UNIDEN one's and they are very poor. I recently got to see the new ICOM one that is not only supplied with the R-1, but now also sold as a separate item. It looks good and I am assured it also works good. Radio rallies are good places to pick up ex-pmr two way radio ducks. I have bought several, and almost all of them out-performed the standard scanners duck. Remember that pmr ducks will have been cut for one specific band or even frequency, and in that area they work great, just don't expect good results if you start scanning up and down the bands. Another approach is that if you have a specific band of interest, then get a rubber duck made cut to your preferred band. I have had several made for just such a purpose. They look good and work great. * MORE HINTS* If your are planning putting up a new external antenna, a really good investment is a roll of self amalgamating tape. The easiest place to buy this stuff is usually plumbers merchants. How it works is that you connect your downlead to the antenna for example, then taking about ten inches of this special tape you stretch it to about twice it's normal length. Then proceed to wrap it around the joint starting from the top and tightly wrapping it around the entire joint. If you stretched the tape enough, after a while it will start to bond together or AMALGAMATE. You end up with as near a watertight joint as you can get. It really is good stuff. Forget PVC insulating tape mainly because the adhesive breaks down after a while, and it is most definitely NOT watertight. MOBILE ANTENNAS A number of companies such as Radio Shack/Sandpiper/Antenna Specialists sell complete set-ups for scanning in the car. What you usually get is a miltiband antenna, a suitable length of coax, and a plug on the end. The idea is that you buy one, whack it on the roof, connect up your scanner and off you go. The question is, are they any good? Well surprisingly enough most of them are. I have tried the Radio Shack and the Antenna Specialists one and they were both well made, heavily chromed and had reasonable coax attached. However I have seen other ones that looked like they were constructed by someone who had little more idea of antenna theory than I did. It is worth remembering that these antennas are tuned to the major bands of interest in their respective countries. Therefore purchasing one from the States for example, and using it in the UK will give less than impressive results. You have to remember that apart from the international marine and airbands, these two countries use completely different bandplans. A good example is that the popular cellular band in the USA is at 800MHz whereas in the UK it is 900MHz, so a USA market cellular antenna, or a scanner antenna peaked on the US cellular market will give VERY poor results over here. And unlike PMR business antennas, most of these multiband varieties have moulded joints and thus cannot be trimmed or altered in anyway. INTERESTED IN MONITORING A SPECIFIC BAND? Well then build your own! It's dead easy to do. Take a well known PMR antenna supplier, obtain their catalogue or visit a local stockist. Most of them sell very good quality magnetic mounts or MAGMOUNTS as they are better known. They all seen to adopt their own universal mounting system. Most popular in the UK is the spade type. As long as you buy your whips from the same producer as you bought your magmount or through body mount, then the whole thing will slot together nicely. The best thing about using PMR kit is that to a trained eye like mine, one cannot tell straight away that there is a scanner onboard. Plus they look very neat and professional. But to me the best feature is that the actual whips are very cheap, you cut one to low band VHf, one for high band VHF, get one of their centre loaded UHF whips, and compliment the set off with one of their centre loaded cellular antennas. You now have four cheap whips that can easily be swapped over with nothing more than a single allen (HEX) key. They work great in their allotted bands. The two bands you might notice the greatest improvement over an off the shelf all rounder like the new Radio Shack model are the UHF and CELLULAR bands. If you are transmitting or just scanning UHF then a five eighths over five eighths centre loaded whip will leave all other types standing. Well that's about it for this article, if you have read everything off the screen as opposed to printing it out, then your eyes must be out on stalks by now. Cheers Nigel.