![]() ![]() This is another reason to use a Scout, as it will also capture unwanted signals, however it will hopefully also capture the signal that you are looking for. #Fluke multi counter trialOf course, there is a caveat that even with a hold feature, the benefit is limited as there is generally a good chance that there will be a lot of trial and error as the frequency counter will lock onto the first strong signal it detects in the area which may not be the signal you are ultimately looking for. The hold function will save in its memory the first frequency the counter locks onto, which saves you from having to write down the frequency with pen and paper. If you choose to get a frequency counter other than the Scout, be sure to get one with a hold function which will continue to display the frequency after the counter is out of range of the frequency. Additionally, if the budget allows it, an extra scanner doing reaction tuning during an assessment can be a great way to catch frequencies missing during the onsite and offsite profiling. While this is no substitute for proper profiling, it is a good hack if needed. For example, if once onsite there is not enough time for proper profiling, and reaction tuning may allow you to quickly monitor signals in the area. While this has limited usefulness, we have found that in some situations it can be helpful and save time. The Scout also offers reaction tuning, which means that it can automatically tune a compatible scanner to a frequency seen by the Scout. ![]() This can be a huge time-saver, as reading frequencies from a frequency counter screen and entering them into a computer can be a real headache. ![]() The Scout can hold multiple frequencies as well as multiple hits per frequency, and the frequencies can be downloaded to a computer for easy analysis. The Scout has many advantages over a normal frequency counter, and the extra features are very useful for a penetration tester. This is especially true when you have access to the interior of the facility that is being targeted.įor penetration testers we recommend an Optoelectronic Scout frequency counter ( Figure 5.4). It should, of course, be obvious that a handheld frequency counter will generally allow you to get fairly close to the signal source. The law of inverse squares means that the closer you are to a signal, the stronger the signal will be. This makes sense, as radio, television, and emergency dispatch towers must have the power to broadcast over a geographically large area, while the two-way radio transmitters used by many organizations must only blanket a comparatively small area. Additionally, commercial radio, pager, television, and emergency dispatch towers can cause havoc for the frequency counter. This is especially difficult when in a signal rich urban area or when there are multiple transmitters in a single tower. With the proliferation of wireless phones and the wireless network towers, it can be a challenge for the frequency counter to lock onto a signal. It is becoming more and more difficult to find a place where there is single signal in a low noise area, as today’s world is an extremely RF-rich environment. The frequency counter will display the closest “near field” signal, which must be approximately 10–15 times as strong as other signals in the area, and the closer the frequency counter is physically to the signal, the better the chance that the frequency counter will be effective. ![]() Frequency counters work best at counting a single signal in a low noise environment, as they need a signal that is high enough over the noise floor that the counter can separate that signal from the background noise and only count that waveform. An important caveat is that if there are multiple transmission frequencies in the vicinity, the frequency counter will give false data as it will likely combine the oscillations and give an inaccurate frequency count. They work by counting the number of beats, or oscillations in the airwaves of a set period of time, giving the frequency of those oscillations and thus the transmission frequency. #Fluke multi counter portableA portable frequency counter ( Figure 5.2) is one of the most valuable pieces of equipment for onsite profiling. ![]()
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