By Jason Reilly.....

 

Stealth is defined as the ability to do something without being noticed, and is often used in a military context.  I'm sure you've all heard of the 'stealth fighter' and 'stealth bomber' and so on.  The definition of scanning, in our context, of course will need no introduction.  So, 'stealth scanning' is the act of using a scanner in a manner that will not be noticed by others.

 

Why would you not want to be noticed carrying our your beloved hobby in a stealthy manner?  It might be that you have neighbours that do not approve of your 'nefarious activities' or you wish to discreetly monitor an event without having awkward questions being asked of you, or you might just not wish to draw attention to yourself.  One person I've heard of was in the unfortunate situation where it was common knowledge that he owned a scanner, and people in his neighbourhood accused him of listening in to their telephone calls weather they had a cordless or mobile phone or not.  Closer to home, some of us have had receivers stolen from our property, so using stealthy scanning techniques will help in not attracting attention from the less than law abiding community.

 

 

Covert Scanning At Home:

 

If there is anything that attracts unwanted attention or at the least curious stares, it's a plethora of antennae on the roof of your house.  My own neighbours are fairly tolerant, but I just know what they are thinking whenever they look at my antennae.  Does this sound familiar?  If it does, and you want to do something about it, read on.

 

If your house has a tile roof, why not consider moving your outdoor antennae within the roof.  This has several advantages: protection from the elements and storm damage, and it hides the metal away from prying eyes.  There is the slight trade off of not being able to raise the antennae to beyond the roofline height, thus sacrificing some signal capturing ability.  I have successfully operated both a discone and a VHF dipole within the roof space, and I can vouch that it is a darn good idea.  I used string to suspend the discone close to the ridge of the roof, and the dipole was suspended directly from the rafters.

 

 If the antenna-in-the-roof trick is not for you, how about the drainpipe antenna trick?  A stink or vent pipe that extends out of the roof, usually near the edge of the roof, does not even rate a second look from the neighbours.  Why not make up a fake one of these, and hide an antenna inside that?  A tile with a short section of pipe can be bought from a hardware shop, and this is used to replace a normal tile.  An appropriate length of PVC is then glued to the short length of pipe, and your antenna installed inside.  A small vent cap can also be bought and glued onto the top of the PVC pipe to complete the illusion.  For a metal roof, a hole can be carefully cut, and then the PVC pipe and antenna can be located.  It would be best to have the pipe extend within the roof space and secured somehow, and a silicone sealant can be used to seal off the joint between the roof and the pipe.  Antennae suitable for use with this method include collinear or stick type antennae, or even the do-it-yourself drainpipe antenna as described in the April '96 issue of R&C.  Even a UHF CB collinear could be hidden inside, but at 2.5 metre's or more tall, it's getting to the limit of what would look sensible for a stink or vent pipe.

 

Why not use a television antenna as your scanner antenna?  It sounds silly at first, but the humble television antenna is inherently designed to be broadband from some 60 MHz to 800 MHz, depending on the model, which is just perfect for scanning.  The 300 ohm impedance of most TV antennae should be transformed into a 75 ohm match using a standard TV balun.  Some TV antennae already have 75 ohm terminals, to which you can attach your coax directly.  Do not be too concerned with the 75 to 50 ohm mismatch, you will only loose a minimal amount of signal.  I have used an FM (88-108 MHz) antenna as a long range airband scanner antenna, and it worked extremely well, so the idea is quite valid.  Remember that the TV antenna is directional, so you may need to carefully adjust the orientation to achieve the results you want.

 

Other less effective ideas can include using a telescoping whip indoors, or, if you can find it, a pair of telescoping whips in dipole configuration with suction cups to attach to a window.  Tandy have a device that will allow you to add you own antenna terminating in a BNC plug to stick to a window listed in their current catalogue.

 

I won't leave out our HF friends at this point, either.  From my limited experience with HF, a longwire located in the roof space can do well I'm told.  I've also heard of people connecting antenna wires to metal curtain rails or running long wires underneath the carpet.  I have experimented with an 'invisible' 5 MHz dipole, run horizontally along my wooden fence, and it does quite well, although the noise level is a bit higher than would normally be desired.  Another design I've seen uses the telephone line as an antenna, with best results being obtained with aerial lead ins (the type that do not come in underground) The local telephone company may not be too overjoyed to learn about an unknown HF receiver connected to it's telephone line, so I couldn't recommend this, but I've included the idea to show you that you need to go beyond conventional thinking.  Think not 'why?' but 'why not?'

 

 

Stealthy Mobile Scanning:

 

Your car is a target.  A target for thieves, made all the more attractive by scanner antennae that just scream out 'steal me'.  Those same antennae also attract unwanted attention from vandals, passers by and some less well informed law enforcement officers.  Lets hide those antennae, shall we?

 

Firstly, consider if you even need an external antenna.  If all you listen to is the local police with their high powered repeaters, why would you want an external antenna?  Even if you only listen to simplex stations, modern handheld scanners are devilishly sensitive, and it's own antenna will probably do anyway.  The handheld scanner also means that you can take it with you when you have to leave the car.  You can still go a-scanning while away from your car and it will be safe from theft.

 

If you have been through this, and still consider that you need an external antenna, there are a few suggestions that you can follow.  The first is using the car radio antenna for your scanning activities.  A splitter is used to feed both your scanner and your car radio.  Tandy used to sell these, but they are easy enough to make.  A small project box is used to house the splitter, with metal being preferable, but a plastic box will do OK, too.  A car radio socket is used as the input connector for the splitter.  Solder one end of a 100 pF disc ceramic capacitor and one end of a 100 ohm resistor to the centre pin of the connector.  Get some thin, flexible, but well shielded (i.e. good quality) 75 ohm coax and install a car radio plug on one end.  The other end is stripped back so that the inner conductor is bare and can be soldered to the free end of the 100 ohm resistor, and the braid soldered to the outer of the splitters socket.  Similarly, a length of good quality flexible RG58 coax is terminated with a plug suitable for your scanner at one end, and the other end stripped back so the centre conductor can be soldered to the free end of the capacitor and the shield soldered to the splitters socket.  The car antenna is plugged into the splitter's socket, and the 75 ohm cable goes to the car radio, and the RG58 of course goes to the scanner.

 

Would a magnetic mount antenna do the job for you?  This is easy enough to remove from your car when you have to leave it, and sacrifices no performance.  Or if your interest lies mainly in the UHF band, a glass mount antenna can be bought from Dick Smith (cat D4019) which looks a lot like a cellular phone antenna.  This device can be used for transmitting, too, if that is your thing.  I realise that on-glass antennae can be bought for other bands (VHF and 27 MHz) but at these frequencies, they tend to be a bit big and thus loose the covert look.

 

A second car radio antenna can be installed to your car, and this wouldn't look out of place at all.  The difference is, it is connected to your scanner, not your car radio.  I've used this trick, too, and it works very well, especially at VHF.  I haven't seen them for a while, but you should still be able to buy those car radio antenna that come as a very thin wire embedded in some clear adhesive tape that you stick to the inside of your windshield, which could be used as a scanner antenna.  I imagine that the system that uses the rear windshield demister wires as the car radio antenna could be a bit hard to tap into for scanner use, but none-the-less, it's a concept worth remembering.

 

I have also seen an attempt at hiding a UHF quarter wave antenna on the rear parcel shelf of a vehicle.  It was certainly safe from damage from the exterior of the vehicle, but was still noticeable, semi-stealthy, if you like.

 

 

Undercover Scanning:

 

When away from home and car, your handheld scanner can go with you to keep you in touch with the action.  Having the scanner on your person need not mean that you have to make your hobby obvious to one and all.  There are two schools of thought here: hide in plain sight or just hide without drawing attention to your handheld scanner.

 

Hiding in plain sight couldn't be easier: have the scanner on your belt as if it were a mobile phone.  It's amazing how many people will mistake a scanner for a mobile phone given a few simple accessories.  A leather carry pouch or case, the type with the clear window will help complete the illusion and a small antenna; how many mobile phones do you see that have a telescopic whip or a thick, heavily wound helical antenna?  Also, don't have the volume turned up so far as to attract attention.  If in an area where any sound might attract the wrong sort of attention, it might be best to turn the thing off for a while.  Think of how a police officer might feel (and what he or she might say) if they hear their respective base blasting out of your 'mobile'.  I was once at a venue with my scanner and was approached by someone saying "it's no good mate - those mobile phones don't work around here".  Little did he know....

 

Hiding without drawing attention to yourself is another method that I use.  This is where you have your scanner in use, but is hidden away, underneath your coat or jumper.  Wearing those little in-ear earphones will not attract any attention.  Most people would think you are listening to your walkman or a portable compact disc player.  Don't try using a single earpiece, this will look suspicious.  I also use a converted speaker-mike that does not have the mike plug fitted, plugged into my scanners ear jack.  I have a remote volume control on the body of the 'speaker-mike' and wear it under my jumper, near the collar.  The audio doesn't need to be turned up too loud since it is close to your ears, and should the need arise, I can turn down the volume quickly without having to dive for the scanners volume control.

 

Finally, while I'm not using the scanner, I house it in a slightly oversize camera carry case, again an item which does not attract attention, even at airport X-ray security examining points.  Another fellow that I know keeps his portable scanning equipment in a specially compartmentalised briefcase with the receivers, antenna, tape recorders and spare batteries all neatly stowed away.  Goodness knows what people would think if they saw what lay within, but I'm sure that the word 'spy' would enter the minds of a few!

 

 

Stealthy Techniques:

 

While using these techniques will not hide your activities, here I'm assuming that you are out using your scanner to chase a stealthy target.  Using a few simple techniques described here will help you to locate and to monitor your 'stealthy' target.

 

First, find your target.  Look at the antennae in use and make an educated guess as to the frequency band in use (VHF lo/mid/hi or UHF or 800 MHz).  Then, if you have a scanner capable of Wide-FM, set your scanner to that mode, and use large steps, 50 or 100 KHz.  Search around for any strong and likely signals using these settings.  Once you have found a signal, quickly tune it in with the correct mode (narrow FM in most cases) and the correct step.  The wide-FM mode allows faster initial searching due to the larger steps and the wider 'window'.  For those without the luxuries of Optoelectronics Scouts or Xplorer's, this method comes a close second to quickly locating unknown frequencies when close to your target.  Of course those who have access to either a super fast scanner like the new Uniden Bearcats or a spectrum analyser need not worry too much about this!

 

One important note to make here is that if you should hear an event or happening that common sense dictates that you should not be in the general vicinity, then stay away!  Bushfires, police operations, emergencies or just plain dangerous situations are all examples of places that you should monitor from a distance.  On the other hand, air shows, sporting events, community events and the like are just perfect for going out to monitor at close quarters with your scanner.

 

Some of the results I have had using 'stealth scanning & techniques' are quite startling.  I've been able to monitor and disseminate the communications of at least 2 US Navy aircraft carriers, listen to a national VIP's security escort (what are all these men doing talking into their hands for?), even listen to Prince Charles personal bodyguards!  Not to mention the more 'mundane' military operations, security forces on 'habitation' (the lingo for 'stakeouts') and lots of other events I'm sure that certain people would prefer that I never had heard.

 

So, there you have it, 'stealth scanning', the art of not being seen but still being able to hear.