(Continued from Part 1.)
‘Sweeping’ a Band
If one can afford to buy several scanners, then that would be optimal. We should have at least three, given the old adage: “3 is 2, and 2 is 1, and 1 is none.” We can keep one spare scanner in a Faraday cage, and store it elsewhere. Then use the other two scanners: One to scan from a list, and the other to sweep the band, or particular parts of a band. Each scanner will have an operator’s manual to help. If I could only sweep one band, then it would be the 2 Meter Ham band, or sweep all the way from 144 Mhz to 162 Mhz as that is where most of the analog radio traffic will occur.
Advanced Methods of Scanning
Because my Area of Operations (AO) is remote, and where digital is seldom encountered, I put my meager resources into a bank of seven used analog scanners that each are utilized, together and separately, to intercept the most likely frequencies that might have traffic.
Scanners can perform in two different ways. They can be set up to ‘scan’, scrolling through hundreds of specific frequencies that have been programmed in, and to ‘sweep’ a band. Using a scanner to sweep a band, the scanner scrolls through all of the usable frequencies by bandwidth steps within a user-determined preference, that can be limited or expanded by the operator. If we are sweeping the entire VHF band, the time need to complete the sweep is extended to 3 to 4 seconds. If we limit the sweep, the time to complete a sweep is greatly shortened to one or two seconds.
Using several scanners to sweep different portions of the VHF band ensures coverage of that portion of the spectrum, and greatly increases the odds of interception. The technique pretty much eliminates the need for a frequency counter that is marketed as Uniden’s Close Call feature, and the range at which interception can occur is much greater than the Close Call feature allows. And we have the advantage of capturing the frequency even if the dispatcher attendant is distracted, or not present. If we used a digital recorder’s VOX function, we can also capture the traffic, and the frequency as it can remain displayed until the user resets the scanner.
Using a Scanner to Monitor Primary and Alternate Frequencies
Baofengs are indeed efficient receivers drawing only 75ma. However, Baofengs are a bit deaf, and their scanning feature is too slow to be used as a scanner that scrolls through a long list of frequencies. An older and slower analog scanner can search through 200 channels every 3 seconds or so. The Baofeng (and other inexpensive transceivers) can however be used to monitor one frequency that is your primary or alternate. A primary and alternative frequency should be a part of SOI (Signals Operating Instructions) used by a security operation. It would be easy to jam a primary frequency just before an attack by simply keying up, or ‘opening a mic’ intermittently, or continuously. A quality mobile radio set on 5 watts can be used to transmit a continuous signal. Therefore a second Baofeng (or other transceiver) should be used to monitor your alternate frequency at all times, even though the frequency is not used.
Scanners should not be used to monitor a primary or alternate retreat security frequency that is in a band that is being scanned. It is quite possible that brief transmission that is less than 2 to 3 seconds in duration, might not be heard, especially if mic clicks (a noise heard when a transceiver transmits and breaks the squelch of a receiver momentarily) are a part of the SOI. If one does not have a scanner, then a Baofeng can effectively scan a very short list of no more than 8 frequencies. Unless there are not enough transceivers for the job, using a more expensive scanner to monitor a single frequency is a waste of resources. It is much better to use a transceiver in this role, so that if traffic is heard, the operator can respond to that traffic quickly, simply by using that transceiver that is conveniently at hand.
Power Management in Austere Conditions: A Scanner as a Reciever of Last Resort
In a long-term grid-down environment, resource management would be a constant struggle. Understanding our equipment goes a long way to optimizing any resource we have. Keeping at least one receiver operational and listening for a report from LP/OP (Listening Post, Observation Post) may become our goal in austere conditions. If our transceiver, that would be a first choice to monitoring a primary frequency consumes more power than my scanner, then my scanner is repurposed to monitor my primary channel, and only that channel. If all else fails and my source of electrical power no longer available, my contingency might be moving the OP in closer and using field phones, or rigging up a wire pair from the OP that operates a noise maker of some kind — a buzzer, or car horn, for example. Or it might be only cordage in a pipe, or a light cannon, or a laser. With the exception of field phones, these other options are not ideal, but work. However, limited by the length of the wire available, or option used, the distance from perimeter to the OP would have to significantly reduced, and this decreases the effectiveness of our security operation. An analog scanner might be the most power-efficient, and best choice to have on hand to monitor not more than two frequencies.
Many analog scanners that lack the bells and whistles of the current generation of scanners on the market, and tend to be more power-efficient. My favorite old-school handheld Radio Shack scanner (with an LCD display) will use only 75ma (75 milliampere hour = 0.075ah). This means our limited power supply might be adequate if power-efficient receivers were used, while power inefficient receivers were not used. During the long dark winters, a small PV system will struggle to replenish its batteries even if the demand ( power drawn) appears to be very small. A relatively small draw of power would be constant, and over time, become significant. Either we must increase the size of the PV system and battery bank (expensive), run a generator (expensive), or use contingency means of creating power, such as a one-wire GM alternator turned by a bicycle, or use the most power-efficient receivers on hand, or all of the above.
For my own purposes, I’ve determined after much calculation that the smallest PV system required to keep at least one receiver functioning for the next eight years by using only the PV system to generate power here in the Intermountain West, should be no less than 800 watts, and have a battery bank of no less than 440 AH in capacity. More would be better, of course. Various means of power production should be another topic.
If a generator is not necessary, then the ability to monitor is not only less expensive, but just as important, our power generation plan less complicated, and thus, more reliable as gasoline goes bad in about 3 years, and generators and chargers can break. (BTW, I use AVGAS 100ll (96 octane) stored in airtight metal cans for a long-term gasoline supply for critical and contingency applications. However, in cold weather, gasoline engines are harder to start on this fuel, but it can remain good to use for longer than 5 years and perhaps up to a decade if store in ideal conditions.)
While modern scanners can be super fast, and offer digital capability, a frequency counter feature (Uniden brand markets this as Close Call), as well as many other features that are appealing, it may not be the best choice when limited power generation presents an operational issue. These models tend to be power hogs, and relatively inefficient consumers of precious power. My Uniden with Close Call drains its batteries relatively quickly. I did not test all of my scanners, and do not have to, because it was easy to see how quickly the Uniden used up batteries. It does so, alarmingly fast. It will not be used during the darkest winter months.
If faced with a long dark winter and minimal isolation (sunshine) of less than one hour per day to recharge the batteries of a PV system, I might be forced to shut down a large bank of scanners, and to resort to only one of the most efficient scanners on hand. The threat will have been reduced by heavy snowfall on the roads, and the need for monitoring potential radio traffic would be reduced. If the threat condition was high, I would run a generator to keep as much of the equipment function as possible.
(To be concluded tomorrow, in Part 3.)