Radio Reviews

by Blue Whale

Several years ago we trekked out to Austin, Texas on an ill-fated journey - to witness the Steve Jackson Games trial.  While the trial never materialized for us (it was postponed a week, in one of those legal maneuverings that occur for no reason in particular), we did manage to salvage the trip by hanging out in Austin (one of the hippest places around) and by testing out what was then considered some of the best commercial radio equipment available.

Texas is a great place to go scanning, with its endless miles of open road and its military ranges spanning the distance between population centers, and we were prepared with nothing less than a Icom IC-4SRA and Optoelectronics' frequency counter, Model 2600, of course.  The idea, as I recall, was to catch local frequencies on the Opto and then listen in on the Icom.  As it turned out, the Opto turned out to be the weaker link in this radio dyad.

First off, to actually get a verifiable frequency you had to watch the LCD while random "background noise" frequencies flashed by.  Then, if by chance you happened to spot a number which more or less remained constant, you then had to flip the "hold" switch and hope that the frequency wasn't yet another pager system or birdie or what have you (our model was state-of-the-art; earlier models did not even have this highly prized hold switch).  Then, just when you thought you had this little system down, the sun would set and you'd have to break out the night vision goggles to read the LCD in the dark.

Needless to say, we ended up breaking that Opto unit in a fit of blind retribution, and dreaming up a wish list of features that we thought the unit should have included.

Enter the Scout

The Scout is the embodiment of everything we wanted on that trip.  With this one product Opto has redeemed itself in our eyes.  It is truly a hacker's dream.

Basically, it's a palm-sized frequency counter with a back-lit LCD that stores up to 400 filtered frequencies and supports reactive tuning and computer interfacing.  The unit also has a beep mode and a silent vibrating mode to alert you to frequencies it captures.

Typical operation involves turning the unit on, say, in vibrating mode, putting the unit in your pocket where it vanishes out of sight, strolling around somewhere, and then experiencing the thrill as your Scout occasionally vibrates to alert you to a captured frequency.  Unlike our old unit, the Scout utilizes a filter to exclude the random background noise that so irked us out in Texas.  Signals must be 10 to 20 dB stronger than the background noise in order to squeak by the filter and register as a frequency (you may, if you wish, turn the filter off, in which case the Scout will function like a normal counter).

What happens when you get a frequency depends upon what mode you're in.  If you're in beeper mode, you will hear a beep of course (one beep if the frequency is already in memory; two if it isn't).  Additionally, you can set the backlight to switch on for ten seconds (this is very useful when you're in the car, as you may not hear the beeps but you will certainly notice the blue backlight).

In vibrating "stealth" mode, the vibrations replace the beeps and you cannot set the backlight to automatically turn on.  You may cycle through the frequencies at any time by going into memory recall mode.  This will display not only the filtered frequencies you've captured, but how many hits on each frequency (up to 255).

The Scout utilizes an internal NiCad battery that charges fairly quickly, sometimes in an hour.  When powering the unit down, you must place it in recall mode in order to keep the frequencies that you've captured in memory.  This is by far the most annoying design flaw in the unit.  Instead of the Scout defaulting to recall mode, it takes an effort to place the unit in this state.

As a result, if you accidentally switch the Scout off (or, as is more often the case, someone you're showing the unit to does) and you do not have the Scout in recall mode, you will lose your frequencies.  The Scout must be placed in recall mode each time you want to shut it off with the memory intact, and once you place it in recall mode you cannot use any of its features, so that it's not like you just hit some button when you first get the Scout and forget about it.  Basically, everyone I know who owns a Scout has, at one time or another, lost frequencies because of this.

A Note About Models and Versions

The Scout has gone through a number of software and hardware revisions since its original inception.  The latest one appears on our bills as "Scout 3.1" which now supports reactive tuning with AOR's AR8000 (a wide range cellular-capable receiver, also reviewed in this article).  Version 2.0 will also support reactive tuning with the AR8000 although you will need to use a small battery-sized circuit board in between.

R10A FM Communications Interceptor

While the Scout is certainly worth the $449 you will spend on it, the Interceptor at $359 is questionable.  Some people swear by it (see, for example, Thomas Icom's article, Cellular Interception Techniques, in the Spring 1995 issue of 2600), but my own experience leads me to conclude that the Interceptor is not for most people, hackers included.  It is definitely not for someone who is thinking of purchasing their first receiver.

First off, the Interceptor is not a receiver in the conventional sense.  The best way to describe it is to compare it to a frequency counter, only instead of displaying the strongest near-field frequency, you hear the signal deviations.  The result is that the Interceptor will automatically "tune" to the strongest signal it encounters, be it AM, narrow FM (NFM), or wide FM (WFM).

In theory you can take your Interceptor with you in the car and listen to all the cellular conversations you want.  In practice you will be annoyed and frustrated at your inability to selectively tune the various areas of the spectrum you wish to monitor.  If you live in a city or some other highly saturated area, your Interceptor will be practically useless, as all you will get most of the time are pager signals and commercial FM stations.

While the Interceptor does come equipped with a skip button that allows you to skip to the next strongest frequency, it is not very effective as strong signals will block out the weaker ones you will invariably wish to listen to.  In rural areas, the Interceptor is somewhat more effective, as there are obviously less competing signals.

Finally, I must point out the most annoying quality of the Interceptor, that being its inability to maintain two-way communications signals.  Although the latest Interceptor comes with a "delay scan" meant to correct this problem, the fact is that it doesn't work.  Thus, the second your local police dispatcher releases his mike, you will lose the signal and once again be listening to pagers or commercial FM or what have you.  Pressing the skip button a few dozen times may get you back to the conversation, if only for a brief moment, but who wants to monitor something this way?  It's too bad that the Interceptor does not come equipped with that beloved "hold" switch that is thoughtfully included on Opto's frequency counters.

Near-Field Receiver / Bug Scanner 30 MHz - 2 GHz Testing Optoelectronics Interceptor R10

APS104 Active Preselector

  

Not worth it.

At $995, the APS104 is certainly one of the priciest toys you will buy from Opto.  The problem is that the features just don't match up.

Basically, the APS104 (measuring approximately 7" by 4" by 1.5") goes between your receiver (a Scout or Interceptor or what have you) and your antenna.  You then tune a 4 MHz passband between 10 MHz and 1 GHz by rotating a knob up to ten times.

The APS104 will block all frequencies above or below this pass band, resulting in a theoretical increase in range for frequencies that fall within this band.

My problem with the APS104 is its non-linear analog tuning.  When you get your unit, it will come with a custom frequency calibration chart depicting 11 frequencies and their corresponding dial settings for your particular unit.  Thus, to tune the center of your 4 MHz wide filter to 825 MHz, you might in fact have to tune to 510 MHz on the dial.

Needless to say, using this in a moving vehicle is akin to using the old frequency counters.  And if you lose that paper chart out the open window you're out of luck, not that the chart is even remotely useful unless you happen to be interested in those particular frequencies.

In a world in which digital tuning is no longer the exception but the rule, Opto should basically let the process of natural selection do its thing and retire this dinosaur.  Again, as with all of Opto's products, the documentation for this unit is completely unreadable and unhelpful.

Teardown, Tutorial & Experiments with Active/Passive Microwave Bandpass Filters (APS104)  The Signal Path, #204

Universal M-400v2 Decoder

Not an Opto product, but one which I thought I would mention just the same.

As digital signals become more and more common across the radio spectrum, products such as the M-400, which is able to decode many types of signals including pagers, will gain in importance and popularity.

Unfortunately, I was not able to acquire a unit for testing.  I was, however, able to order an owner's manual from Universal Radio, something I suggest everyone does with every expensive product before ordering the product itself.  Just one glance at the manual was enough to confirm my suspicions that Universal is a lot like Opto when it comes to documenting their products.

The manual does, however, clarify many of the questions I had concerning the M-400.  For example, the unit can only store up to 8k of information, has extremely limited programming capabilities, and does not have a computer interface (although I am told that at least one company is working on such a product, and Universal Radio does sell a similar model that plugs into a PC).

So far as I can tell, the only reason that it is called the "M-400" is that it costs $400.

AOR's AR8000 Wide Range Receiver

As with the Scout, the AR8000 is enjoying immense popularity in the hacker world, and rightly so.

The most important reason why you should own this $600-650 unit is that it receives 800 MHz cellular imaging loud and clear on its 1400 MHz band, with absolutely no modifications (tune from approximately 1419.9 to 1442.91 MHz in 10 kHz steps).  Or, if you prefer, you can interface the AR8000 to a computer and reprogram its EEPROM to unblock cellular, a service which some people are now offering.

If you're wondering how AOR can accomplish this with our current laws in place, so am I!  In any case, even without these undocumented features, the AR8000 is a great little unit, capable of receiving from 100 kHz to 1900 MHz continuous (less cellular until you reprogram the EEPROM) and in the following modes: AM, USB, LSB, CW, NFM, WFM.

Another noteworthy feature is its ability to store frequencies in non-volatile memory along with eight-character alphanumeric text tags for each frequency.

Lastly, the AR8000 does not use costly internal or external NiCads, but four AAs.

Any device that requires a sheet of paper in order to tune is not worth your time, especially when that device costs $995.